BUILD ARTICLE

In this article…

This build article will be by date starting at the top of the file. To see the build in the order it happened, scroll down the file. This is the actual order I used to build the plane and that is not to say it was the best order, simply the one I decided to use given the circumstances I encountered. The kit was from Balsa USA and my evaluation of the kit is included in the words and photos contained herein.

10/4 - 10/13/09

Initial steps

The kit arrived and showed no external damage. The 3 boxes were opened and inspected with no damage noted.

The hardware parts were inventoried and stored in a container as that will avoid handling damage to the wood. The rest of the kit was then inventoried and the wood inspected. Some of the wood will be replaced for better quality, but most looked fine. The wood was then organized by size and all die cut parts were separated and bagged according to major sections of the plane.

The plans were in several sheets and I studied them before begriming the build.

The supplies for the build were confirmed and a list of items to purchase was begun.

The decisions that needed to be made before the build could begin were:

1. Engine Selection -- for this issue I rely on the experience of those who have succeeded with the same plane. I checked with Dick Pettit who owned one of these planes and placed in the middle of the pack at Top Gun two years in a row. He had a Zenoah G-62 and was pleased with the plane. We were thinking a larger motor to get to a twin cylinder motor and the smooth idle that comes with a twin. After consideration, we decided on the G-62 with a spring start.
2. Servos -- This is key because the Ercoupe is unique in the way the twin rudders work. Each rudder moves only to the outside as movement to the inside would cause it to hit the elevator. The design of the plane uses one servo and a bellcrank with linkage to accomplish this rudder movement. With the use of a modern radio, we can program this function into the servos and use one on each rudder. I selected a thin servo for the rudder and it will fit in the thin stab with ease. The other servos were selected for the required power and digital servos were not used as there was not a clear need for them.
3. The wing will be in three parts to make the plane easier to handle.
4. The painted parts of the plane will receive automotive quality paint and that will be done by a body shop.

Other decisions will be made during the build, but these were the key items that would change the build.

I met with Jim and we decided that brakes will be a good addition to the plane for the short runway at the Alex city filed might be a problem for a plane this size.

 

 

10/14/09

BEGIN WITH THE WINGS

I had a chance to begin the build so I set the plans up on the table and began with the center section of the wing. It will be in 3 parts so that Jim can wheel the plane in the trailer with the wings off and in the trailer.

I started with lamination of some parts that needed to be doubled.

The wings will each have a wing tube that is square aluminum and will take the stress of the weight of the plane. These tubes will slide into each wing section and be secured. I built the tube pockets with 1/8" ply and glued the four sides over the tube which had been covered in wax paper. I made 4 tube holders and set them aside for later

The wing center section was stick built over the plans and below you can see the built - up spar with the tube holder glued in place. the locat5ion will match the structure in the wing. The dihedral was built into the spar in the front and the one in the back.

Next I added the ribs behind the spar and short rib ahead of the spar to form the front of the wing and to make structure around the tube holder.

The structure was then rocked to the other side and glued up as I did on the first side. You can also see the internal leading edge in place as well.

The other leading edge was glued on and then the bottoms were planked. After the glue was dry, I trimmed and sanded the entire structure to shape. You can see below that one wing tube was put in the tube holder and fits very well.

The center section will have the air system for the brakes installed prior to the top planking being put in place.

The Left wing was then set up by taping the plans to the board and wax paper was placed over the paper plan. the structure was then pinned in place and glued with fast CA. The main structure is scale and will perform very well for this size wing.

Next was the wing tip and it is scale to the very unusual tip designed for the full scale Ercoupe. It is a complicated structure that requires some time and lots of parts to complete.

In the shot below you can see the tip without the reinforcements. The shape of the tip is distinctive and will be very strong when completed.

10/15/09

This is the real tax day and mine went in the mail to be post marked and the end of the tax year has arrived again

The wing tips were then glued as there are 5 layers of wood on the tips and it takes time to get this done. These laminations are done with white glue as the CA would be so hard that I could not shape and sand the tip.

The wing tube box was then reinforced to be sure there will never be an issue with it working open and becoming loose. I doubled the supports and added gussets until I was satisfied that we had a ridiculous amount of strength in the area.

I then added webs between the spars as that is essential to the strength of the wing. The joints were then all re glued to improve the strength of the joints.

 

10/16/09

The final wing section was then put on the board and framed just like the one above. I like to frame them and then plank and fit the center section with both wings at the same time. This gives a more consistent fit and improves the straightness of the final wing. this one is 10 feet long so we need to keep it straight and true. The framing was complete and the wing tip was laminated.

below you can see the second wing framed and the tube holder installed as before. The spar webs are in place and the frame is ready to be removed from the board.

 

I test fit the three wing sections together to ensure the joints were done correctly. There is always some tuning that has to be done to the joint and this was done in preparation for the next step

 

Below you can see the left wing joint. The wing tube is in place and the the fit is very good The sections will have a peg in the rear part of the joint to stabilize the flight load on the wing.

 

The wings were then sanded and shaped on the top and bottom to ensure the planking will go on the frame smoothly. I began with the bottom of the wings and planked the leading edge ahead of the spar and the trailing edge with a 5/8" section of planking. This must be done correctly as it will warp the wing if not done right.

The cap strips were added and the leading edge planking was bent to match the shape of the wing tip. This planking will make a very strong wing.

Below you can see the right wing fitted to the center section and pinned at the trailing edge of the wing. The pin is secured in the corner of the wing by glue and a block that increases the strength

Below is the finished joint with the pin in place and the fit was checked to be sure it was correct.

The rib upper surface was sanded to match the two parts and when the planking is added it will be a nice match. This wing is straight and clean so far and I will need to figure out how to hold the wing sections together .

Below you can see the wing in the assembled condition. There is a lot to do before the upper planking is put on the plane. The center section will hold the air system for the brakes and the wings will have the servos for the ailerons. Once all the gear is in place, I will plank the sections and make hatches.

10/18/09

The next step was to make the attachments for the wing tubes. The tubes will be glued into the tip portion of the wings and the tubes will then need to be secured to the center section. I began with the blocks that will hold the bolts. The blocks were then fitted to the top of the wing tube boxes. I then drilled for a clearance hole for an 8-32 bolt and set a blind nut in the bottom of the block The block will hold the bolt without attempting to thread the aluminum wing tube. The bolt will then thread into the blind nut and proceed through the tube to pin the tube in place.

The block was then counter sunk for the bolt head and a washer. The assembly was then complete and I decided to wait to glue the block in position. I need to find something to use on the top of the wing to disguised the bolt as a fuel port

Next I framed the servo mounts for the ailerons. I will use the hatch as the mount for the servos and I started with a hard wood frame and then cap stripped to supply strength to the area.

10/19/09

I then made a hatch and mounted the servo with a slit for the servo arm.

The assembly was then mounted on the frame and the rest of the bottom of both wings was completed with some reinforcements on the ribs.

The leading edge planking for the top of the wings was not the proper quality so I edge glued some of my stock to make a sheet wide enough. After the sheets dried, they were soaked in water and glued o the leading edge.

The trailing edges were glued on along with the cap strips on the top of the wings. The leading edges were then glued in place and allowed to dry

After the glue was set I shaped the wings to the rough configuration and filled any imperfections. I will leave the outer wing panels in this condition until just before covering and that way I get less handling damage the airframe

 

The next issue is building the ailerons and they are constructed upside down over the plans with balsa center and ribs on the top and bottom. I began by laying the plans back on the board and getting all the parts set up for construction.

10/27/09

The session began with the completion of the preps for building the ailerons. These are odd because there is a curve upward on the bottom of the ailerons and this must be done right to make the surfaces line up. They are constructed inverted on the sheeting that will be the top side.

After they were framed, I rough shaped them and set the blocks for the control horns. I then sheeted the bottom of each aileron and set them aside to dry. This is one of the applications for white glue as it let me sand the panels to match the wings once the glue was dry. The shape was adjusted and the taper of the leading edge was set to allow the required throw on the aileron. The new ailerons were filled and set aside.

I began to set up the parts for the stab and elevator as that was the next item to build. the parts were gathered together and the plans studied as this is a complicated part of the plane. The rudders are on the end of the stab and they will move so there has to be servos in the bottom of the stab as well. This all takes some planning and I worked on the plan until I was satisfied I was ready to build.

10/30/09

The trailing edge was pinned down to the plan along with the spar and the ribs were added followed by the top spar. The inner leading edge was glued on to compete the structure.

The shot above shows the bottom of the stab and I framed in hatch openings for both sides. The thin servos will be in the openings and the control arm will come out the bottom of the stab to operate the rudders.

I then sanded the structure to shape and planked the bottom it with 1/16 material. I then planked the leading edge of the top of the stab and sanded the internal leading edge flat. I glued on the outer leading edge and shaped it to final shape.

The rudder servo bays were next and I cut a ply hatch and mounted the servos on the hatches with the control hours protruding through the lower stab skin.

 

When in place, the hatch will be invisible and will be attached with some unusual linkage that will be shown later in this article.

10/31/09

The day was spent putting in the servos on the stab and getting the operation to work correctly. I designed the final version of the linkage that will push the rudders outboard but not pull them inboard. This linkage is complicated so I built a mockup and tested it to be sure it will work correctly. Everything is in order for the rudder operation.

Next I got the parts together for the elevator and the twin rudders.

11/1/09

The elevator was constructed flat on the plans with a sheet of balsa and the ribs supplied in the kit. The leading edge was glued in place and the assembly was then sanded to shape.

Next I planked the top side and sanded the entire thing to shape. It was then ready to be hinged and I set it aside for future assembly.

 

I then got all the parts together for the rudders and fins. I drew the rib placements on the two sets being careful to make one right and one left set.

11/2/09

The session began with the construction of the rudders. The building included leading and trailing edges on both sets and then ribs and the doublers around the edges. The rudders are hollow to save weight and they will be hinged and then mounted to the stab.

After the building was done on one side, I shaped the structure flat on the fin sides and tapered on the rudder sides. I then planked the inside of each system and then shaped them and beveled the rudders.

11/11/09

The fuse was the next part of the build and this will take lots of time to build. It is very detailed and began with the plans on the board covered with wax paper

The crutch was constructed from thin strips of balsa and they were curved to match the plan and then laminated to make a strong center rail for the fuse. The top will be constructed directly to the crutch and then the bottom will be built on the inverted side of the crutch. Below is a shot of the crutch constructed and then it was trimmed and sanded flat

The first former is the one on the edge of the side glass for the cockpit. I have decided to make the side windows slide like the full scale one did and that will require some steps very early in the fuse build. I began by building the f5 former from 4 parts of ply and shaping it to match the curve of the plans.

 

11/12/09

The next step was to build the window tracks and this was done by laminating 1/32 ply with balsa to form the sliders. I then began assembling the top of the fuse on the crutch. the formers were glued in position and the tracks were assembled to the large formers shown below

You can see that the top part of the canopy is framed below and the tracks are in place for the sliders.

below is a close shot of the track that will hold the canopy material. It has ply on both sides and a spacer in the middle. This was then assembled to the former and glued to the crutch after checking it for square.

Once the formers were in place I set the stringers in the front and back. This adds a lot of strength to the system and gets us ready to plank the upper decks.

The kit came with a large sheet of very thin ply and I cut the sheet into the parts that will be the planking around the fuse. I cut them all out and that will save the trouble of doing it in single parts.

The planking began with the front deck and I laminated the left and right sheets with CA and then glued them to the frame. The crutch was beveled so that the ply would follow the curve of the formers right down to the bottom of the crutch material.

I propped the crutch up off of the board with 3/8 material so that the planking could be overlapped on the crutch. This gives a neat job of gluing. After the front deck I did the rear canopy area and it was one side at a time.

below you can see the rear canopy parts are on with holes cut for the windows.

The front of the upper 1/2 of the fuse is planked in the shot below and it is looking like and Ercoupe already. You can see that the front windshield will be installed from the front deck to the standing frame. The sliders will go between the standing frames and the rear windows will cover the holes in the planking.

11/13/09

This session was devoted to completing the sheeting on the top part of the fuse. The back part was done in one sheet and it took a good bit of fitting to get it right, On the front side it needed to fit with the window planking and all the stringers and formers had to be sanded straight and rounded so that the ply would fit without any buckles. Once it was fit I glued it beginning in the center of the turtle deck and working down to the crutch. this was done in 5 successive glue sessions and it came out looking fine. I then removed it from the board and double glued the joints from the inside. The sheeting was then trimmed to the crutch and inspected to be sure it was straight and true,

11/16/09

After sanding and shaping the upper part of the fuse it was time to begin the construction of the rest of the body of the plane. I began with the construction of the formers from the nose to the tail.

The former above is under the instrument panel and was constructed to fit the crutch width and to glue in place on the bottom.

The former above was constructed to fit under the forward canopy track and after I did the former and sized it to fit the crutch, I built a track that would match to the track in the upper half. This will complete the circle track on the forward end of the canopy.

The former and track shown above is the rear track for the canopy and it was very precisely made to fit so that the tracks would line up when assembled.

the rest of the formers were assembled and set aside to be used later.

Next I made a former that was tall enough to support the upper part of the fuse and I checked to be sure it was parallel to the table and square to the center line. I then nailed blocks to the work table and nailed the former to the blocks taking care to make it square to the table surface. This is the first support for the inverted fuse. The support system will be completed and the crutch will be flat and supported for the next part of the build.

11/17/09

 

The building of the formers was completed and each one is different.

Above you can see the fixture as I set it up. There is a support at the nose and one at the tail former with a straight edge to confirm the crutch is straight.

I started building the formers at the front. Each former is set in position and then glued with reinforcements as needed.

In the shot above you can see that the upper and lower formers with tracks had to set the tracks so that the window could slide through the joint. The track formers were done so I set up the tracks so they are good to go

The rest of the formers were set in place per the plans.

Next the stringers were set and the alignment checked before gluing them all in place. The glue was allowed to cure and the stringers were trimmed and the fuse was sanded to shape. This took a long time but will pay off once the planking is on the plane.

11/18/09

The session started with a complete check of the fuse. I checked for straightness as this will be the last chance to adjust anything on the fuse.

The planking on the side of the fuse is very hard because it is a compound curve. The solution is to use strips and custom fit each strip to the curves of the fuse.

The planking was set for most of the side and allowed to dry.

11/19/09

The first fit of the center section of the wing was done and all is well. The wing fit on the formers rather well and it will be fine tuned later in the construction.

The fuse next got the ply planking on the bottom of the fuse. This was one sheet and it was glued to the framework.

The front of the plane was next and that allowed me to get the new engine out of the box and check it out. It is a Zenoah G-62 and that will be a fine motor for this plane. I inspected the motor and everything looked very good

As you can see in the shot above the spring starter was not on the back of the motor so I assembled and checked the starter. It bolted up and the shot below shows it with the mounting plate installed and ready to begin to set it up for the plane.

In order to tell how to build the motor box, I laid the motor out on the plans and found that the motor is nearly correct for the full length design of the motor box. The shot below shows that the motor would be 1/8 short of the perfect position if the motor box were built per the plans.

As you see above, the motor was set up on the plans and I like the position of the motor. It is easy to put a shim behind the motor mounting plate to move it ahead, but impossible to move it back once the motor box is constructed. With the layout done, I began constructing the motor box.

Above you see the rough motor box in position and it will get the ply firewall in the front of the box.

The next part was the 45 degree brace for the box. I fitted it and there will be additional structure in the nose area once the box is done. Remember the fuse is still upside down and the motor will be inverted so that the exhaust will come out the bottom of the plane.

11/21 - 22 /09

The interior of the plane needed to be planned so that the equipment would be accessible and could be hooked up properly. I turned the fuse right side up and attached the center section and added the wings for the first trial set together of the plane.

In the shot above you can see the plane is fitting together very well and the main compartment is quite large. There is a seat that fits in the center and there is a cargo compartment behind the seat. I found several photos of planes that had an open area behind the seat but most had a cover over the cargo compartment.

You can see there will be an instrument panel in the front of the main compartment and you can see the forward track in which the windows will run.

In the shot above the area aft of the rear window track will be the cargo compartment. I now believe that the best solution would be to put the equipment in the cargo area and put a cover over the area that will be easy to remove to get to the equipment. There is a front seat that will also be easy to remove and that would give access to the elevator servo and all the gear.

 

The rest of the session was spent designing the interior of the plane so that it can be secure in flight and easy to remove without any tools. The design is not complete but great progress was made.

11/24/09

The session began with the motor box assembly to the plane. I checked the alignment and glued the box in place. I then glued in all the support parts and then reinforced with triangle stock to give the maximum strength we can get from the structure. Since the engine has lots of power, we do not want any strength issues with the nose of the plane.

Next I changed the arms on the throttle and the choke to allow good linkage to be hooked to them and for the direction of travel to suit the plane. These arms will allow the ball links to be hooked up.

It was time to begin the interior and I decided on the operation of the inside of the plane. The floor and seat bottom will be glued in place and the seat back will be easily removable. The cargo area will have a cover that will also be easy to remove and will hold all the equipment for the plane. The pilot will be strapped to the seat and will flex as the seat moves. The switches will be behind the seat or up on the dash depending on the way the equipment fits in the space.

I began the install with rails in the upper cargo compartment. These will hold the cover. I then build a system to hold the floor in place. This will allow the seat back to be pinned securely to the floor.

I then set the floor and checked it to be sure it was flat. As you can see above, the floor ends where the seat back partition will intersect the floor.

The walls were next and they were put in place with CA to ensure a strong structure. I tested the seat in positron and it all looked good.

I wired the switches to the fly board and also extended the wires on the rudder servos before ending the session.

11/25/09

I completed the side planking and made the seat back. The ply material for the seat back was sized to fit the walls and pull out through the window area since that is all that will be open once the plane is done.

below you can see the back being lifted out and the bottom of the partition is pinned into the floor structure. This will secure the seat back in flight.

In the shot below you can see the blocks and pins that hold the partition from moving fore and aft. The rail at the top is beveled and will be glued in place to retain the cargo deck.

With the seat back in position, you can see the seat fits well in the space and is high enough to give a lip over the back deck.

 

Next I added a structure and a removable back deck over the rear of the cabin. This deck is scale to the planes we have been able to find. The tow bar and the tool box will be added later for realism. The seat back locks the rear deck down for flight.

I finished the structure that holds the back deck and then it was time to begin the equipment installation. I first considered the switches and the air fill as they are things that will need to be accessed every time we fly the plane. I decided to try to mount this gear behind the seat as we could just rock the seat forward and get to the switches and air system to charge them up as well as turn everything on for flight.

Below you can see the panel on the left holds the ignition switch and the air fill as well as an air gauge. On the right are the two main switches with charge ports built in, You can also see the structure that holds the cargo deck. There will be more structure as the other items are built in the equipment area.

The next thing was the mount for the fly board and the receiver. This location is key since we will be running all the wires to the servos from this board. The batteries and switches also connect to the board and it must be placed where we can access the equipment easily.

11/26/09

I constructed the servo mount for the elevator servo and mounted the batteries. The rest of the equipment install will wait for another day

The fuse was then inverted and propped into position for the center section to be reinstalled and this time I aligned it to the table top based on the aluminum tubes. I also adjusted the tramble to be sure the wing tips were the same distance from the tail and were flying in the same direction as the nose.

In the shot above you see the center section was clamped to the fuse formers and then screwed in 4 places to hold the alignment. I then inverted the fuse and added the wing panels to check that the wings were on flat to the cutch. I used a long straight edge to confirm the wings were flat and a string to the tail section confirmed the tramble.

I then repositioned the fuse and glued in some forward formers in preparation to glue the center section in place.

11/27/09

The leading edge was glued onto the center section and shaped to match the leading edges on the two wing panels. This is key to the flight of the plane so I used templates to be sure the leading edge was the proper shape.

Next there were more planking strips to put on the fuse before the center section was put on for good. In the shot above you can see the floor of the passenger compartment and the string that will help feed the wires from the front of the plane to the equipment compartment. The floor was not per the kit as I found a better and lighter way to build it. I extended the floor ahead to the back of the F1 former as that will give a better look to the inside of the plane and will allow some additional structure to be added to the nose. The area ahead of the wing will have to support the motor box and take the forces from the nose gear. This structure work was done prior to attaching the center section.

11/29/09

Before attaching the center section, I wanted to test the assembly that will support the sliding windows on the side of the canopy. I made tracks that form a circle to the bottom of the fuse and I needed to conform the operation of the tracks and that the windows will really slide as they were designed. This is a unique feature and soon the tracks will be planked over and adjustments would be hard to make.

So I cut a spacer in the top of the tracks and slid in the window panels. I left the protective coating on the panels and they did slide down the tracks and under the main compartment. The final install will have lead bars on the sheets so that the plastic material will not bow out and become disengaged in the tracks.

The shot below shows the windows up and everything seemed to work pretty well. I was satisfied enough that the rest of the work could continue. There will be a bar and a latch at the top of the cockpit that will link the two window panels together at the top. Many times the pilots of the Ercoupes would fly with the windows down without any ill effect and the same thing will be true of this plane.

 

There is a front windshield that will be mounted in position and there is clear material for the rear windows, so everything we do to service the plane will have to fit between the side window frames.

When getting ready to fly, Jim will lower the windows and check the charge on the batteries and fill the air brakes from inside the cockpit. He will then turn the three switches on and set the seat back in position. He could then raise the windows and he will be set to fly.

As you can see in the picture above, the planking on the lower part of the fuse was glued in place and then sanded to shape. This planking will not intersect with the wings as there is a large fillet that will connect the two surfaces. All the internal joints in the planking were then double glued and further reinforcements were added to the inside of the fuse.

11/30/09

The big decision to attach the wing center section was at hand and I made all final checks to be sure there will be no regrets later in the build. While I am confident that I have already made every error on planes that can be made, I did not want to push it.

I mounted the wings and bolted the center section into position according to the marks made earlier. I confirmed that the wings were in the perfect position and I removed the wing panels and inverted the fuse.

Below is a shot of the center section and you can see the servo screws used to hold the formers from the fuse to the ones from the center section. I used fast CA on all the support structure and I re-glued several times and then went over the joints with medium CA for good measure.

After the CA dried without using accelerator, I added the 1/4" square stock you see above. At the leading edge I added structure to be sure the strength was up to the level we want.

With the structure in place, I added stringers to the front former and, as you can see above, I added one last section of floor up to the f1 former in the front of the fuse. Everything was double glued before the planking was applied to the fuse.

Above you can see the planking on the front part of the fuse was then put on and sanded to the proper shape. This planking takes time but makes a fine job of the compound curves that are all over the plane. this is the very same way the full scale plane was constructed.

12/1-- 2 /09

I then planked the center area of the belly and sanded it to shape. As you can see below, there are still open areas on the planking and these will be covered by farings that will be put on later in the build The bottom of the center section is strong now, and I will return to it later.

The leading edge will also be added on to later and for now it is all set.

Next I set up the stab by assembling the plane and placing the stab on the stab mounting plate. It is key that the stab be flat to the wings and be straight on tramble. Tramble is the condition that one tip is ahead of the other and that creates problems in the air.

Flat to the wing can be measured as distance up from the table at the tips. You can see that the stab is flat to the wings by looking at the angle below. I also measured from the wing tips to the stab tips and made sure they were the same.

To mount the stab on the fuse, I first reinforced the center area with ply and then put in a block of hard wood. I drilled the block for a 4-40 bolt on the drill press to be sure it was straight.

I then set the stab back on the marks I made earlier and drilled through the mounting plate . I slid the bolt in place to position the rear of the stab.

Next, I checked the alignment again and bolted the two lead bolts in place. After a final check, the blind nuts were put in place and the stab secured to the fuse. The stab will also be glued in the final assembly as the loads on this area of the plane are very high and I want the strength to be at the max. Since there is no need to remove the stab, We would rather have the strength in the tail area.

Next the wire tube was installed that will contain the rudder servo wires. It is key that these wires not be loose in the fuse and that they pass through the bottom of the stab and not interfere with the control rod for the elevator.

The tube for the antenna was installed at the same time

The control rod for the elevator was then made from an aluminum rod with 4-40 threaded rod leading to the servo mounted earlier. The rear of the rod was fitted with more threaded rod and connected to the elevator control horn.

The elevator was hinged on to the stab and the control horn was attached. The control rod was hooked up and tested with the servo.

Next the stab tips were glued on and the rudders were then bolted to the stabs. In the final assembly they will be glued and bolted to be secure and to follow the scale appearance.

 

12/11/09

The session began with the mounting of the rudders to the stab with blind nuts and #2 bolts. I will glue these in place later, but the bolts are scale and will hold them for now. Once everything was on straight and true, I hinged the rudders to the fins. This is tricky as the rudders only move one direction so the bevels are not the usual ones.

I then began the first assembly of the links by putting the rudder servos in the stab and inverting the assemble

I set the control horn and then made the linkage you see below. The servo arm has a sliding brass fitting and a wheel collar makes the arm push the rudder out when it moves.

When the servo arm moves ahead, the brass fitting slides on the linkage and the rudder is not pulled inside the straight line. I will have to devise a stop for the rudder to be sure it will not move inward and hit the elevator.

I completed both rudders and then assembled the stab on the fuse. Below you see the left rudder is turned to the left but the right rudder did not move left.

below, the right rudder command was given from the transmitter and the rudders work as they should. With the completion of the rudder construction, I could then plank up the stab and the sides of the fuse.

The fuse was inverted again and the joints were checked and re glued if needed.

The last of the part orders have been placed for the cockpit interior and the instrument panel. The kit comes with an aluminum dash and I found a company that makes authentic gages to go in the dash. The parts are on the way along with some yokes and other interior labels. The pilot is also on order and I believe he can be automated to turn his head with the rudder command.

12/13/09

 

The glue strips were set for the side planking and the planking was trimmed and fitted to the opening. The sheets had to fit on all sides so the trimming took a long time to get done right. The sheets were glued in place and accelerator was used to hold the sheets.

Below is a shot of the side sheet in position

The sheets were checked and the joints got filler in preparation for sanding and final shape. The sheets were in position correctly and this completes the skin of the fuse. These are complicated constructions because of the double curves and the fuse came out without any buckles or spots that will have to be repaired before covering.

Next I set the tail block that will later be shaped to the fuse.

While the glue dried, I began the work on the upper planking of the center section.

The shot above shows the aileron wire and the air tube for the brakes. I reinforced the rib joints with triangle stock and gussets to be sure there was no chance of a stress failure aft of the main spar.

The final step before planking was to finalize the screw attachment of the aluminum tube to the center section. I will glue the tube in the outer wing section after covering, but there will need to be a screw through the tube on the center section side to hold the wing on in flight. I did not want to put this on the bottom of the wing as it would be inconvenient so It must go on the top. In this version of the plane, the gas tank filler was near this location so I decided to make a fuel tank fill that is scale and it will cover the bolt that holds the wing on.

A close look at the plane above will show the gas cap. I set about making a gas cap that will work and cover the bolt in the wing tube.

12/14/09

I made blocks that fit on top of the wing tube ply and fill the gap to the top of the wing. That block was drilled and counter sunk to allow a 5/8 dowel to fit in the hole. I then made the dowel look like a gas cap from the real Ercoupe . As shown below, the bolt was then epoxied into the cap.

The block had a blind nut in the bottom that allows the bolt to be threaded down through the block and into the wing tube. The shot below shows the finished block glued in place. The block is thicker than needed because there will be planking on the top of the wing.

You can see the finished product below and after covering the block will not show and the gas cap will be scale and I am thinking of painting it yellow like the one I saw. In the shot below the planking still needs to be trimmed and that will be done as the center section is mated up to the wing panel.

Next the equipment for the brakes was gathered and I decided how to install in the equipment compartment. The air canister was first put in and tubing run to the air gauge and the air fill port on the front of the equipment area. This will not ever need to be removed so it is put in for good.

The air will go from the tank to the valves where the transmitter will actuate a servo to pressurize the brake lines. The mini servo was mounted on a board and the primary flow valve was mounted so that the arm of the servo hits the black button on the valve. The valve will then open and the air will flow to the flow control to the left of the valve. This is an adjustable control that will determine how fast the brakes pump up and stop the plane. The knob on tip is the adjustment and it was tested after the install was complete. The air lines were positioned near the gear and will be connected later on.

Next I began the farings for the trailing edge of the wing. The glue strips were installed first so that the 1/64 ply would have a surface to glue to. The shape of the ply was very gradually adjusted to fit the curve of the fuse and glued in place. The upper side of the faring will be put in later after all the equipment is in place.

You can see the glue strips in the shot below and the rear spar in the center section. This is the last access to the bottom of the equipment compartment, so I checked everything before fitting and gluing the other faring in place.

The left faring was then put in and the main consideration is that the two panels be even and symmetrical. The second faring took more time to fit because of these factors.

12/15/09

The work session began with the design and cutting of the fire walls for the motor box. The large one will be glued to the motor box and the smaller one will serve to position the motor so the cowl will fit as it should

Next I cut the top of the motor box away to allow room for the spring starter that protrudes from the back of the motor. The front of the box is square to the line of flight and the thrust line is marked on the top and the side of the motor box. These lines will be used later for alignment of the engine. I also decided to double the front former that was 1/8" ply. This will add a lot of strength and provide a nice edge for the planking.

I then assembled the nose gear box as the plans described it. The hole in the bottom was fitted to take the servo that will control the nose gear steering. This is a high powered servo and it will be mounted in the ply bottom of the box

The box was adjusted and carefully aligned to be square and straight and then glued to the motor box and the front former with epoxy. The trick here is to avoid getting glue in the corners as there will be hard wood triangle stock in there later and it fits better if there is no glue fillet. The string is in positron to pull the wires back to the equipment compartment under the floor.

the shot below shows the gas tank in position with a stop in front and foam on all sides. The leads are passing into the motor compartment and the install is easier if done before the fire wall is put on the motor box. There is a velcro strip on the back of the tank to allow it to be removed from inside the plane if need be. The lines were marked as fill and vent so I can avoid that embarrassment on the motor test.

The hard triangle stock is also in the front of the motor box and lots more will be added to increase the strength of this assembly. It has to hold the motor and take the stress of the landings too.

In the next shot you can see the triangle stock and the fire wall is screwed - not glued - to the motor box so I can fit the motor. The upper cowl brace is glued and screwed to the area above the motor box and it will support the cowl.

The cowl rails were fitted to the plane and glued in place. These are hard wood and will help hold the cowl on the plane. This takes a lot of fitting and trial assembly to get right but it is worth the time to get the cowl on right.

the cowl is now close to the right position and we need the motor in position to get it just right.

The best way to set the motor is to get the fuse straight up and let gravity hold it for us. This looks strange but is the best way I have found to get the cowl and motor to be right.

The motor is just put up there with the proper thrust washers. The fire wall is straight so the down thrust and the right thrust is done by washers as shown below.

Once this was all set, I slipped the cowl on and then positioned the motor to match the cowl.

Once I got the motor positioned and the gap between the spinner and the cowl just right, I lifted the cowl off without moving the motor and marked the mounting holes. I tend to do this more than once to avoid the problem of drilling in the wrong place.

Once I had that good feeling, I drilled the motor mount holes.

12/16/09

 

The assembled motor mount was then returned to the plane and set in the proper position with the cowl. It was then fast ca'd to the fire wall and then removed from the motor box.

The fire wall and the ply spacer were then checked for alignment and the firewall was glued in place and lots of reinforcement was done while the epoxy dried.

Next thing was to figure out how to work the throttle and the choke servos. I made linkage and mounted them in place. The wires were extended to reach the equipment area under the back deck and the wires were run. The nose gear servo was then mounted and the wires run for it as well.

The spinner arrived just in time and the cowl was test fitted with great success.

The exhaust has not worked out well and further work will be done on it to be scale for the plane.

The equipment was then turned on and the servos set up to the transmitter and adjusted for full operation.

12/17/09

The pilot figure arrived and I automated his head by building a box that was placed in the chest area of the figure. I mounted a servo in the box and made a pair of dowel extensions that faced upward. The head was then filled with foam and the dowels were set into the foam so that the head was in position but was suspended by the servo arm. When plugged in to the rudder circuit, the head turned and the action was very scale indeed. The servo lead will plug in and the pilot will be seat belted into the seat. The figure was reassembled and came out very well.

The next issue was the wing farings and they were aluminum on the original full scale plane. They were removable so that the wing spars could be inspected and they were not smooth or very aerodynamic.

The farings that came with the kit were ABS and were very scale in appearance. In my investigation of the planes still being flown, most of the time these farings have been retrofitted to a smooth line and I think the appearance and function are much better than the original.

I started with the wing panels as constructed and the bottom rear sheets in place.

I then cut out the ABS farings that were in 3 parts for each side of the plane. I trimmed and fit the farings to the plane and then glued them in place to be as straight as I could make them.

Above you see the first side and the faring is in place in the rough form. Before any further work was done, I mated up the wing panel and shaped the areas leading to the farings. The view below shows the wing in position on the center section and all the planking sanded to shape. This process took a lot of time and the result was very good.

After this step, I will add Aeropoxy filler to the fillets and they will be sanded smooth to the wing and the side of the fuse. These farings can not be covered with monokote because they are inside corners and there is no way to put shrink covering in them.

I decided the best thing will be to cover the surfaces and mask off the farings and paint them at the same time I paint the cowl. This will give the finish we desire and the look will be just right.

12/18/09

The session began with the rest of the plastic wing farings. They were glued in place and then both sides were rough sanded and checked for shape. Some of the ABS farings were incorrect on the shape and that will need to be corrected.

I used Areopoxy to improve the farings. This is filler made for full scale farings and it dries in a few hours and is sandable. I mixed it up and put a coat of filler on all the farings. I ser it aside to dry.

The wings were then checked and improved to get ready to cover. The ailerons were inspected and filled as well.

12/190and 20/09

The left wing was first to cover and the bottom of the wing was done first. the ribs were ironed down to give the scale look and the servo bay was covered. The servo wire was extended so that the plug would reach the hole in the wing root and the servo mounted.

Below you can see the trick to secure the wire one rib back from the root and the wire will never get way inside the wing.

I then covered the top of the wing and set the hinges in the covered part. I mounted the hinges and then covered the aileron. Below you see the covered parts. Next will be the stripes and then I will mount the aileron and hoop up the hours and linkage to the servo.

12/27 -29 /09

covering continued on the wings and the left wing had the striping put on and the aileron attached.

The right wing was then covered and checked out for problems. The servo covers were monokoted and mounted in the wings with extended wires.

 

12/30/09

The rest of the wing covering was completed and the wings are ready to go. The control horns were then put on and the linkage made for the ailerons. I tested them on the plane and checked out the aileron motion.

I then did the second coat of interior paint. Since the interior will be done in gray fabric, I am painting gray as well. The seats will be done in black and it will all look very nice.

While the paint sets up I removed the wing panels and the final step was to epoxy the wing tubes into the outer wing panels. I roughed the tubes up and then glued them in place. The screws under the gas tank caps will secure the wings to the center section and the assembly will be easy to do.

The skin is now on the fuse and it needs some filling and inspection. I began with the bottom and sanded the first coat of filler and put the final coat on in the few places that needed it.

I turned the fuse over and sanded the upper part and the wing farings. It is all looking good and needed some additional filling. I added the final coat and set it aside to dry.

1/1 and 2/ 10

I spent real time sanding the fuse and getting it close with Aeropoxy and filler once I thought it was close, I used primer as an indicator on the rear of the fuse. I will sand most of it off and that will indicate the low spots.

The fillets were sanded along with the fuse and they are getting near completion. The scale farings are rough and removable and I opted to sue the smoother style for this plane. as you see above, they are close to where I can paint them. The monokote will cover the wings up to the farings and the rest will be paint.

I then put the cloth on the seat and test fit it in the plane.

I next started on the tail assembly by planking the top of the stab. All the work is done on the rudders and stab, so it could be closed up.

I covered the rudders per the color plan.

After the sanding was done, I covered the bottom of the stab and the elevator. The hinges were put in place and the servo doors were covered and mounted with button head screws. The assembly is nearing completion and it will be screwed and glued together after the fuse is painted.

12/03/10

 

Next I covered the upper side of the stab and hinged on the elevator.

The rudders went on to test the positioning, the final assembly will be done later.

The shot above shows the mounts for the rudder and the bolts are scale to the plane. The linkage was hooked up and checked for operation. Below is a shot of the stab on the fuse and you begin to see the potential in the plane.

1/4 - 6 /10

The fuse needed to be sanded and worked to get ready for paint. After the first prime coat, I sanded as much of the primer back off as I could. This sanding is done with a long block as I was trying to sand off the high spots and leave the primer in the los spots. Below you can see the light and dark spots after the first sanding was done on the upper and lower areas

There were still some pin holes and low spots so I filled them with red lead. This is very smooth and will then be sanded back down to the flat surface. The read lead sands very easily and will get the rest of the low spits filled in.

This process was repeated several times and the result was a surface that looked a little odd but was smooth and ready for the second prime coat. on the rear

 

Next I sanded and filled the lower area and it got the first coat of prime.

The landing gear system requires a lot of silver solder and machining. I started with the wheels and the air system and assembled all the parts with lock tite.

The machining and prep was then done and the parts made ready for the silver solder and assembly planned for tomorrow.

1/8/10

The parts of the landing gear are steel and the landing gears are scale and fully operational. Since this plane has some weight to it, the gear is very well built to withstand the occasional heavy landing. There is a lot of silver soldering to assemble the parts. I will not describe the silver solder process as that would not enable you to do it. It requires training and equipment you will likely not have. If you need to do this stuff, go the a welding shop.

The first issue was the nose gear. This is spring loaded as a shock absorber and it steerable by a large servo in the nose. The parts below are the completed items and from the left they are.

 

Steering tube -- silver solder was used on the lower tube and the servo control horn

Main tube -- the ring at the bottom was silver soldered

Mounting tube - had the plate silver soldered to the tube.

After the process was done, there was a great deal of wire brushing to get the corrosive flux off of the parts.

The nose gear was then fitted into the fittings on the nose. The parts were assembled as shown below and the assembly was tested for proper operation. the shot below was with the gear extended all the way

The shot below shows the gear compressed

Below is the assembly all buffed up and ready to put in the plane. The spring goes inside the tube and supplies the shock absorber action to the gear. The plate will be mounted to the ply motor box.

Below you can see the assembly mounted in the plane and the control horn is in position to be hooked to the servo.

I set the plane on its feet to check that the nose gear shaft was square with the main gear. As you can see below, it was adjusted to be straight.

Next I attached the linkage with ball links to make the steering wheel worked. The assembly was tested and worked just fine. The direction of the servo will be set later using a servo programmer to be sure that right is right.

The parts of the main gear are shown below and there were several silver solder joints done there as well. At the bottom of the photo are the four shafts that were constructed from tubing and some brackets and washers. The assemblies are nearly ready to be assembled.

Since this plane has brakes, the wheels and hubs were replaced with Robart wheels shown above. The shaft diameter is larger than the wheels provided with the kit. The shafts shown above will not fit correctly in the wheel hubs and that needed to be addressed.

I started with some welding rod and reduced the OD to fit into the wheel bearings. I then center drilled the rod to fit over the old shafts and allow the wheels to work. I then cut the tube into 2 sections that were long enough to fit in the wheel hubs. This corrected the problem and allowed the wheels to be assembled.

1/9/10

Looking at t he wheel hub I noticed there were pins in the hub that were to lock the hub to the gear arm. The lower arms were drilled to accept these pins and the wheels were assembled to the lower arms.

Below is the shot of the hub in position with the pins in place and the air fitting ready for hookup.

Next the arms were assembled with all the parts made in the last 2 days. The upper arms have the interlocking tubes assembled with a large spring to act as a shock absorber for the main wheels. The wheels are assembled with the brakes and the wheel hubs.

Below is the inside of the strut and you can see all the mechanical parts of the gear. The initial assembly was then complete and the plane was ready to put up on the gears.

below you see the plane on the gears before any adjustments were made. The gears will be adjusted so the wings are level and so that the plane sits with the nose level to the ground. Those will be done at a later time.

With the gears on, the cowl could be aligned and put on the plane. The first trial fit of the cowl revealed that the choke servo was in the way and so I moved the servo and remade the linkage to make it work. the results are shown below.

The muffler was attached so that the cowl could be fitted.

The nose gear was the first area for cowl adjustment and that was done so that the nose gear can be removed from the pinion gear and then the cowl can be removed. Because of this discovery, the bottom of the cowl had a hole in it rather than a large slot. This will make the cowl stronger and will last longer than if the slot were used.

The cowl was rough fitted to the plane and the spinner was put in place for alignment. The cowl was then in position as shown below.

The shot below shows the cowl with the gear on and the prop attached. This worked so well that the cowl mounts were then examined. You can see the horizontal rails that will be used to mount the cowl and I then looked for places to mount it at the bottom of the cowl. I consulted photos of the plane to see where bolts were located and I tried to hit the same locations for the mounts.

In the shot below I checked the ground clearance of the prop when the nose gear is fully depressed into the spring. The clearance looks fine

I installed a block at the bottom of the cowl beside the nose gear servo and reset the cowl. Once aligned properly, I began with the smallest drill in my set and drilled one location of the mount. I left the drill in the hole to pin it in place and went to the next hole with another drill bit. In this way I drilled all the locations for the cowl mounts and the cowl was checked for position after each drilling. You can see two or three of the drills in the shot below.

Once all the locations were done, I went back to the first drill and drilled and set a button head screw. Soon all the screws were in and the cowl was secure and mounted in a good position.

Below you can see the blisters on the front of the cowl. These are scale and were glued in place and then filled to be sanded with the rest of the cowl.

1/10/10

The cowl was sanded and primed. I then found some areas that needed work so I filled the surface a second time and primed again. This process continues to get a paintable surface.

The shot below is before sanding the second time and I hope that will be all the work it will need.

There are several more paintable parts that needed to be done and I started with the tail cone. This finishes the rear of the fuse and hides the linkage for the elevator. On the real plane it is removable and since Jim will not be able to take off the stab and elevator, this cone will need to be removed for service and repair.

I started by fitting it to the fuse and gluing the parts together. I then filled the joints and set it aside to dry before sanding and priming

Next I worked on the longarons on the side of the fuse. The area around the windows is unsupported and therefore needed external support in the full size plane and on this one. I made the curved sections and fitted them to the fuse.

The parts shown above are to look like the aluminum angles that are on the full size plane so I did not taper the edges very much. They were then glued on the sides of the plane and I spent a lot of time getting them straight and even with one another. When they were correct, I glued them on the side of the plane and double glued from below.

As you can see above, this will straighten out the buckles that were in the side of the fuse and this completes the rough construction of the exterior of the fuse.

10/11 and 12

I visited the paint shop and they are setting up the colors. They looked over the work and decided to test the paint system on the wood and primer combination we intend to use. We are not interested in a surprise when we paint the fuse. I made samples and delivered them to the shop.

The interior needed the cloth look so I made panels out of 1/64 ply and covered them with the cloth for the interior.

Using 77 spray adhesive, I made the two side panels and the floor and installed them.

The seats are done in black fabric and I positioned the seat and covered the back of the seat after attaching it to the back bulkhead. This seat also got the seatbelt for the pilot. After adjusting the panels the interior looked very nice.

The seat back can rock ahead so that you can operate the switches or the back seat and the pilot can be removed by pulling it straight up. The pilot has a plug that can be unplugged to remove the seat and pilot for more extensive maintenance.

You can see above that the side walls and the rear deck are in place and I only have the final fasteners to put in and it will be complete.

The dash panel and the center bar will be put in later . There will also be a visor to finish the top deck and give some support to the front windshield.

1/13/10

I started the session with the layout of the dash panel. I decided to use wood for the dash so I cut the panel to fit and set up the gages up on the face.

The holes were cut in the the dash and the gages fit in place. The panel was then painted to make it white as that was the color of most of the planes I was able to get photos on.

As you can see above, I also set switches and other items on the dash to get ready to put it on the plane

The steering rods were drilled and put in and that completed the prep for the installation of the dash panel

The dash was then fitted and screwed in place and the other items were added to complete the dash area.

While I was waiting for the paint to dry, I used Jim's transmitter to set up the gear and set the throws on the servos that were hooked to the plane. This is a time consuming process and it must be done so that the first flight will be easier. In the shot above, the floor is not in final position and the wood you see ahead will not be visible when it is all fastened in lace.

 

1/19 and 20

The paint system checked out and we are OK to finish the fuse surface and get it to paint. There are several things that needed to be cleaned up and so I started with them.

The interior sides were screwed in place as was the floor and the lower seat. I decided to use screws in case there was a need to get into the sides in the future.

I also applied the visor to the top of the fuse and it covered the dash panel. Later it will be covered with the black fabric to be scale.

Next I wired the Ignition switch and mounted it in the engine compartment. This is a relay that closes a circuit that grounds the ignition to the motor and prevents it from sparking. The relay is activated by channel 7 on the transmitter and I tested it to be sure it was working properly.

In the shot below it is the square box directly under the throttle linkage and the carb.

The surface of the fuse was the next priority and it got one final sanding for shape and a final sand at 600 grit. This prepares it for priming and some of the side has not been primed as yet. After all the prep was done and the wings were masked off, I primed the fuse by spraying the top and allowing it to dry and then the bottom.

1/21

I sanded the primer and added filler to the problem places.

 

Next I covered the lower wing stubs and the lower center section. This covering will save weight and is on shapes that lend themselves to covering.

I then inverted the fuse and covered the stub wings on the top. I then masked the covered areas with auto masking tape and then added plastic to cover everything that had covering on it. I inverted the plane and masked all of the bottom of the plane. There were parts that had not been primed and so I completed the first coat of prime ont he bottom.

 

I once again inverted the plane and sanded all the fill and checked the primer. Once this was done, I primed the second time on the upper 1/2 of the plane and let it dry.

1/22/10

 

Paint shop will take the plane on Tuesday so I continued to prime and sand the fuse and the parts. I just need to build the gear skirts and it can go to paint

 

1/23 and 24

Finished preparing the fuse, the tail cone, and the cowl for paint. The shop will take the plane on Tuesday 1/26. All priming is done and the surface looks good.

The tail cone mount and the main gear covers are all that remain to be done before paint.

The fuse will be painted silver along with the other parts and then the top surface of the cowl will be done with a flat black to reduce glare on the pilot.

The spinner has been primed and painted yellow per the plan for the plane.

1/26

All prep is done and the paint shop will get all the items tomorrow.

1/27

Fuse in the paint shop and they project it will be out on 2/2/10

1/28

wing bags are done for both wings and the rudders. These are for protection of the parts and not for the beautiful sewing of an old plane builder. They will do the job for which they were designed.

2/4/10

The parts are starting to come out of paint. I got the fuse today and I have started on the steps to finish it.

First I mounted the wings and checked the alignment. When they were all set, I drilled the holes in the wing tubes for the retainer bolts. As shown before, the retainer bolts are set up to look like gas caps. When I assembled them for the first time they were not long enough. I removed the bolts from the gas caps and glued in longer bolts.

I then checked the operation of the ailerons and tested the servos for throw and alignment. Everything looked good

I installed the replaced brake shoe on the main landing gear and installed the air line to the brakes.

Next I completed the linkage for the rudders and tested them to be sure they returned the rudders to neutral and they stayed in that position.

When the servo pushes the rudder the stop engages the linkage and the rudder moves.

I began to group the wires inside the equipment compartment in preparation for running the rudder wires which will be the last of the servo hook ups.

The cowl is expected to be out of paint tomorrow as it is getting he anti-glare black top deck.

The insignias were ordered today and will be here soon.

2/5/10

The session started with the paint shop finishing the cowl and it came out very well. The black top deck is just right for the plane.

I began the session with a trial fit of the plane and the result is shown below.

it is moving along well and the first assemble went off without any problems.

The wings were checked to be sure they were level when the plane is sitting on the gears. I adjusted the wings by putting washers under the main gear springs on the low side. This was done and the wings were correct.

The nose gear was fully installed and the angle of attack on the wing was checked so that we can be sure the ground handling will be as expected. If there is negative angle of attack then the plane will pick up speed but not try to fly until you hit some up elevator and then it will tend to balloon up with some exciting consequences.

If the plane carries a lot of positive angle of attack it will try to take off on its own before it has air speed. This will cause a stall and some redesigning of the front of the plane. Since we try to avoid any of these things, I checked the angle of attack and found it to be + 2.7 degrees and that should be just right as we will fill the tank and that will reduce it to around 1.5 degrees.

I met with Jim regarding the graphics package and got it on order later in the day. This plane will be the YO55 which was one of only three types that were military planes. We discussed the appearance and operation of the plane and had a fine time just looking at it assembled for the first time with color on all the parts.

2/6 - 9

I started working on details that need to be done. The front deck of the cockpit needs to be flat black so I cut some fabric to fit the area and used contact cement to glue it down to the balsa surface.

Next, I made the support bar for the windshield. This is square tubing on the full size plane and so I used square stock and made a scale mount for the compass on the bar. Once it was complete I painted the assembly black. The bar was the first thing to be glued in place and I cut a hole in the fabric deck to ensure the bar will hold as it is structural for the windows to work properly.

I then set the compass on the bar and inspected it for correct placement

The tail assembly was next to be assembled and I set the rudders with epoxy and screws taking great care to get them straight and square. After the glue set, I connected the servo linkage and tested the operation

The plane was then set up with the wings on and the rudder servo wires were threaded through the wire tube and attached to the board in the equipment compartment. The stab and elevator assembly was then bolted to the fuse and the alignment to the wings was checked for tramble and flatness to the wings. This was done during the building phase so there were not adjustments needed.

Before final assembly of the tail section, the tail cone was evaluated and trimmed to fit under the stab and set straight with the fuse.The tail cone is removable so the blocks were fabricated and glued to the last former on the fuse.

Below you see the alignment trick for this sort of situation. I put tape back from where the screws will be and put a mark on the line at 2" from the screw. I then fit the tail cone on and measured in 2" and you hit the block every time.

The tail cone was then set in position and screwed to the blocks. It is key that the tail cone be straight and also that it will allow the elevator to go to full down as shown below.

In the full up position the linkage is visible and you can see how the cone is mounted to the fuse.

The stab is ready to be mounted and I took one last set of measurements as the glue step will have to be correct. The plane is looking better with the surfaces all on.

2/10/10

After all the checks were done I removed the tail cone and glued and screwed the stab in place. Once it was dry, I replaced the kwick link on the end of the elevator push rod. The old one was worn from the trial fits. The elevator was then hooked up and the tail cone put in place.

Next I worked on the wiring and tied up all the connections to prevent damage from vibration. This is a tedious process and it takes time to complete.

The brake system was then assembled in the final form and it was then tested. Surprisingly, it did not pass the test as the system did not operate and there appeared to be a large leak that prevented the brake shoes from operating properly. I traced the brake lines and valves and found the repaired brake hardware was at fault. After consultation with the Robart folks, I put the brake shoe back in the mail to be replaced. This is not the norm with the Robart people and, in hind site, I should have insisted on a new assembly instead of allowing them to repair the faulty one. I can continue with the assembly because I can set the brake shoe in place with the gear covers on.

2/11/10

I worked on the fuel system and the lines were run for the overboard discharge and for the tank fill.

In order for the plane to be fuel tight while not in the air, I made a plug and flag assembly that says to remove before flight. This plug is in the discharge line to seal the system up. The second line that fits through the cowl is for the gas fill. It is in a location that is not obtrusive but is functional with the cowl on the plane.

Next I balanced and painted two props for the plane. This will give a spare and the pitch is the same on both.

I tested the spring starter and it was working just fine. I secured all the bolts and the spark plug in the motor. It runs better if the plug is not hand tight. I then blew out the motor intakes and exhaust and final assembled the muffler

The Graphics package arrived and I will put it on with Jim so we can get it right. I checked the layout and it all looks good so far.

I reassembled the brake system and secured it in the equipment compartment. Once all the equipment work was done it was time to begin the rear windows. Cutting and fitting them takes some work. It they are in the opening too tight or loose, the performance is pretty bad.

2/12/10

The session began with the main gear covers. They were made and painted so the mounting was all that was left to address. I used Aeropoxy glue to hold the covers to the aluminum main gear. This is a Locktite product called 9462 Hysol. It is a 2 part glue and it is the best I have ever seen. It is the only glue I use for fiberglass because it works and epoxy really isn't good for formers inside a fiberglass fuse. It will not run and it dries very well. The drawback is that it is a little expensive and it takes 8 hours to set up.

I glued the covers in place and used tape to hold them overnight

 

Next I began the arduous task of putting in the rear windows. I started by tracing the shape on the material and cutting it out. The "glass" had to be about 1/16" undersized to allow for the rubber striping.

I then set the striping on the material and checked it in the opening. After adjustments for size I glued the rubber gasket to the clear material and set it aside to dry before putting them in the openings.

The above shows the glass ready to put in the plane and you can see the protective coating is still on the sheet.

Later in the session, I fitted the glass, with the striping attached, to the hole in the fuse. I adjusted the hole to get a good fit. The flange was then coated with canopy glue and the glass was worked into the opening and taped securely into position. The canopy glue was allowed to sit overnight. I like this glue because it dries clear and you will not see any little bit that might leak out under the gasket.

There is a faring to cover the joint of the stab and the fuse. This cover is screwed to the full scale plane so I thought it ought to be that way here. I started with a paper pattern and cut it to fit the area and then cut the aluminum to the same shape.

I sanded the edges to fit on the plane and then painted the faring.

The front windshield had to be trimmed to fit and then the weather striping was added and test fitted to the plane. This will make a nice look with the black dash area

The front glass was then fitted with the gasket and it was glued to the glass and allowed to dry overnight.

9 steps left to the motor test.

2/13/10

First step for the day was to un tape the gear covers and they looked very nice. The final step on the covers was to pull the rear ends together and glue them. This makes them aerodynamic and minimizes the drag from the beefy gear structure.

The front windshield glue was dry so I checked alignment and glued it in place. It glued against the ledge made by the dash and clamped on the upper bow of the fuse. This was done with canopy glue so it will need a full 8 hours to set up and 2 days to dry completely and be clear.

The rear windows were dry, so I un taped them and checked them for fit and finish. As you can see above, they came out flush and flat.

Next was the stab faring and it was adjusted and screwed to the fuse to look like the full scale version.

The front window will have a srip of aluminum over the clear material to be sure it stays in place and to be scale. Before that strip can be added, the side windows have to be in and working. I began the final side window work by laying out the sheets that will be the slider and cutting out 4 of the upper supports from 1/64 ply.

The upper supports then were drilled for the rivets that will hold them together. There is one support on each side of the slider and the rivet holes were drilled in one to be sure the locations were the same from the left to the right side.

As seen above, I the used canopy glue to glue the two ply parts to the clear material taking care to get them lined up exactly. The wood is extended outside the glass so that the clasp can be made to hold the windows together in flight. This glue then had to sit for 8 hours to set up.

Below you can see the status of the cockpit as the session closed.

The front windshield is in and drying and the rear windows are dry and ready. The strip just in front of the pilot's nose is the one that will have an additional aluminum strip added. The windshield is glued to the wood former and that would likely hold it but the scale requirement is to have the additional strip added. The windows are slid in place through the notches at the top of the formers and once the metal strip is on, the windows will be locked in.

There are now 6 items left on the list and the motor test will be done. Once all the windows are in, the graphics will go on and the plane will undergo final checks. The balance will then be set with all the equipment in and working. The lateral balance will keep the wings flat in flight and the CG is the number one priority for the first flight. Most folks that have tried this plane found it tail heavy and had to add nose weight. While the weight is not something I would enjoy adding, the CG must be right. A tail heavy plane is un flyable and we would need the direct intervention of a superior power to save the plane. Nose heavy makes the plane sluggish and would be fatal if the motor quit in flight.

As you can see, these final steps require absolute dedication to get right.

2/14/10

I began the day with the side windows. The lead end was painted and the rivets were set in each frame. The rivets were hammered in place against a steel block

Once the frames were made, I removed the protective coating and slit the windows in the frame of t he fuse. I slid the window past center to expose the bottom of the glass. I glued on a wood support to stop the bottom of the window from jumping out of the track that continues under the pilot seat. Once the glue was dry I slid the window into position.

Below you can see the windows in the final form and both side windows are up and latched together.

They work independently of each other and the plane can be flown with the side windows in any position you wish. The initial flight will tell if the side windows stay in position with the vibration of the engine.

Below you can see the right window in the full down position The frame prevents the window from sliding too far down.

Next I fitted the metal cover strip over the front windshield edge. The strip was then glued to the frame and screwed to the lower rail to be sure it will stay in place.

Below is a shot of the fuse in the completed form. The cowl and gears are in place and the side window is about 1/2 up.

 

2/15/10

Met with Jim today and we applied all the graphics to the plane including the walk areas on the wings.

It came out very well and we are both pleased. We checked the CG and to our surprise there was no change needed as it measured in the zone shown on the plans. This is a rare occasion with a scale plane. We built it on the light side and the motor is heavier than the one shown on the plans. This accounts for the lucky CG

The total weight of the plane is 29.9 lbs and that is right in the middle of the zone for the plane. Again, with the bigger engine, this is a very good result and means the plane will fly with good energy.

The lateral balance needs some adjustment and there are a few small things to do before the engine test on Thursday.

 

2/18/10

 

Assembled the plane outside and fired the motor up. It started right up and ran just fine. We ran 2.5 tanks of gas and it is running smoother already.

 

As always happens, we found some issues to improve after the plane was subjected to some vibration.

1. The side windows are too smooth and they moved all over while the motor was running. I installed a pin at the top of the track that will prevent any more of this.

 

2. The Elevator servo did not like the vibration of the electrical noise. The next run we are going to change the servo out and look for a change. We will go from there

 

3. The pilot enjoyed the test run but did not sit up straight. I improved the seat belts to include an over the sholder option that will keep him in place.

 

4. The throttle linkage failed during the first run. I realigned and tightened the link and it ran well the rest of the afternoon.

 

Due to Jim's schedule, it will be a few weeks to the next step so he took the plane to the home hanger. Next step is to solve the servo problem and run taxi tests.