Workshop

1/2/10 - 1

I met with Bill Todd and we discussed the kit and how he would like the plane to be done. Bill supplied the kit and most all of the parts and supplies I will need. We had a great time discussing the plane and some programming stuff. Bill also helped me with some fence plans on the new house and shop.

Work will begin as there is time available from the Ercoupe. This is a very high quality kit and the build will move along pretty fast.

1/29/10 -2

I began the plane today by checking the contents of the short kit with the list of materials. Everything was there and I then cut all the parts out from the sheets and discarded the scrap material. This is a short kit so the material supplied is only the laser cut parts and all the sheet goods will be supplied out of my inventory of wood.

In the photo above you can see the parts that came in the kit as I have them set on the table.

Next I taped the tail assembly plans down to a clean flat building surface. I use inexpensive luan doors from a building store. These are less than $20 and are flat. When they get rough from wear you can discard them and each board will last through many builds.

the shot below shows the plans taped down ready to begin.

The first step is to laminate the rudder fin and extension which I did with white glue over some wax paper. The white glue will sand and allow a seamless joint in the finished plane.

Next, I constructed the leading and trailing edges and pinned them down to the board. I made the wing tip blocks from 3/8 sheet and glued them in place with white glue. I cut a 3/32 sheet down to 3/8 wide and fit the rib in place per the plans as shown below.

Next I glued in the center section ribs and tapered them to allow for the center section sheeting. The center strips were then glued together and glued to the ribs as shown below.

the shot above also shows the 1/8 sheeting that was cut with great care to fit over the ribs and still be flush with the 3/8 leading and trailing edge stock. This will give the distinctive diamond shape to the stab that is a key element to making the plane fly correctly.

I then allowed the entire structure to dry for 8 hours.

1/30/10- 2

The stab was turned over and the bottom built just like the top. I then rough shaped the stab and rounded the leading edge. This completes the rough construction so I set it aside for later

Next I rough shaped the rudder fin and the rudder. They were beveled and checked for straightness and then set aside

Next I started the wings with the taping and covering of the plans. I cut the sheet so that I could lay out the two wings in flight position. This way I could build both wings at once.

I first built the spars as they are doubled in the area near the center of the wing

I pinned the lower spars to the plans being sure to get it straight and true. The center section was planned for the landing gear supports. This is an historic weak spot for this kind of wing so I redesigned the landing gear mount. As you can see below, the support will go to the center of the wing and it will tie to the support in the right wing. This will make it much stronger and I then reinforced the support - rib joints with thin ply so that the balsa rib will not fail in a hard landing.

All the redesigned parts were dry fit to be sure they were OK and then all the ribs were dry fit and adjusted to perfect alignment. Below you can see the ribs were then blued to the lower spars.

The dihedral brace was then drawn on some medium density balsa. This was done based on the dihedral called for on the plans. The brace was then cut out and fitted into the left wing root.

Below you can see the brace in position and I was ready to attach the upper spar.

1/13 - 1

I set the upper spar and made two additional braces for the dihedral. The plans do not show these braces and I added them for additional strength in the center section of the wing. You can see below that they were glued in place on the left wing.

I made a gage for the angle of the first rib and glued it in place as shown below. This angle is key to having the halves line up when I put them together.

Next I cut trailing edge strips from 3/32 sheets and fit the first strip in the lower trailing edge slots. when it was straight and aligned I glued it in place.

There are also hinge blocks that were glued in place on the trailing edge along with a large block at the center section. This will be the block for the screws that will hold the wing in place on the fuse.

I then added a 1/4 square trailing edge and sanded the upper air foil shape into the trailing edge. This is tedious to sand properly and it is key to getting the proper shape in the wings and keeping them straight. The same work was done to the right wing

2/2/10 -3

All the blocks were shaped and the trailing edge planking was glued in place. Next i turned the building board around and glued on the interior leading edge. After it was on, I shaped the leading edge to match the curve of the ribs.

Below you can see that the left wing has all the planking on and the cap strips are in place. The 3/32 planking was precut to fit and glued on to the ribs. The cap strips were cut from more 3/32 sheets and glued to the ribs with med CA.

The edges were trimmed and sanded flush with the ribs in prep for the next step.

I then set the left wing in place attached to the right. The wing tip was elevated to 4.5 inches of dihedral and the spar braces were checked for fit. When everything was set I glued and reassembled the wings.

Below you can see the dihedral braces glued in place and the match of the two wing halves. It is key to get these braces in contact with the spars. The plans do not call for these braces, but I use them for added strength since there is not added weight. The plans call for the braces to be cut off at the center section thereby eliminating the brace strength I have added to the wing.

Once the halves were securely glued, I added the center section nose braces shown above. These will secure the dowel used to pin the leading edge to the fuse.

Below you can see the top part of the wing after the planking and cap strips were added and the rough in of the upper structure was complete.

The next step was to sand the edges to clean lines by using 60 grit paper and a sanding block. It is key to always use a block behind paper to keep the cutting straight. You can see the wing tip below is straight and clean. All the planking and tips were sanded to rough shape and filled where there were gaps in the planking.

The leading edge will have one more part added so I left it as is.

2/14 - .5

The under side of the wing was fitted with the landing gear blocks. They were set to mider in the middle of the wing. This will give strength to the dihedral joint and to the performance of the gear.

Once the blocks were set in place dry, I made blocks to fit under the gear blocks. These blocks are a large part of the strength of the gear so I made them from hard wood. They fit under the main blocks and support the end of the gear

As you can see above, the blocks I use go tot he planking on the top of the wing and extend to the gear block. After I fit the block it was glued to the wing.

The alignment was checked and then the gear block was glued to the ribs and the other block.

As seen above, I then used a 1/64 ply doubler on each side of the block to ensure the strength is there.

Once both sides were done I drilled into the blocks and set the main gear. This is the easiest way to assemble the main gear and have all the holes line up. This will produce a strong landing gear and it will not add weight to the plane.

12/15/10 - 7

The session began with the construction of the servo bays in the bottom of the wing. I first set up the 2 servos and checked the receiver and battery combination. I set up the flaperons so that the servos could be no different channels.

The frame for the servo tray was constructed next. and then the leading edge sheeting was put on the bottom. I then trimmed the sheeting and sanded the leading edge flush with the interior leading edge material.

With the frames in place, the outer leading edge was put on next and allowed to dry. Any of these parts that are to be sanded and shaped later are glued in with white glue.

The hatches were made next and you can see below that the servo is set at an angle to the wing ribs. This is to get the servo moving perpendicular to the hinge line of the ailerons. The line drawn on the hatch is ser square.

From the top side you can see the servo is mounted to blocks that are glued to the hatch. The string is in place to pull the wires to the center of the wing after covering.

The view below shows the servo in the hatch and the hatch screwed to the frame. The cap strips are in place and they frame the hatch so that the covering can be ironed to the frame and the hatch covered. This gives a nice clean look to the wing. The center section planking is in place and there is planking on the landing gear mount to build up to level for the covering.

After the leading edge was dry ( I allow 2 hours for the white glue to set up and then I move ahead). you can see the wing was rough shaped and looks very nice on the bottom of the wing.

Next I drew the wing tip shape on the block from the plans. I turned the block and traced the wing shape from the wing tip. This block was then cut on the band saw.

Below you can see the cuts were made on the saw and the result is a rough wing tip that can be glued to the tips and shaped later.

I use tape to hold the parts on the wing while the glue dries. Cutting the tip first reduces the cutting and sanding required later. This is a big time saver.

The finished wing is shown below. It is rough shaped and now needs the ailerons. I will wait for the glue to dry before working on the ailerons.

While waiting for the wing to dry, I began the fuse by laminating the three parts of each fuse side. Note that I made a left and a right side. I have done two rights and it makes assembly of the fuse very tricky

2/16/10 1.5

I started the short work session by shaping the wingtips and filling the imperfections in the wood. The wing is now ready to be fitted to the fuse and to have the ailerons hinged on.

I set the fuse sides over the plan and studied the engine layout. I will use a motor mount that mounts to the f1 former and the nose gear will mount to the same one. This makes the former key to the performance of the plane. I decided to reinforce the joints much like I would a gas plane engine.

I began by laying out the f1 for the center of thrust and mounting the mount to the firewall with blind nuts. The nose gear was then fitted to the back of the firewall with attention to where the control horn will be located. The tank will set behind the gear and the push rods were planned at this point.

The rest of the equipment was planned before the construction began as this saves problems after the glue begins to flow. The nose gear was mounted and the F2 former was relieved to accept the gas tank. There will be room for the three servos in the main compartment and the batteries and switches will be set later depending on the first CG test.

2/21/10 -3

The session began witth a check of the formers and sides of the fuse. the parts were then placed over the plans and the former locations drawn on the inside of the fuse.

the tail section has a ply reinforcement that must be lined up with the 1/2" triangle stock that will be added later. I drew the lines and guled the ply in place

With the fuse halves completed, I placed one half flat on the board and glued the firewall to the side with CA taking cae to make it straight. The first three formers form the front of the fuse and the sides are square and parallel to each other. Aft of that point the fuse halves are bent to a point at the tail.

Since the sides are parallel, the best way to build it is to glue all three to the fuse half and make them square. Below you see the three formers in place.

Next I put the fuse inverted over the plans. The second side of the fuse was placed in position square with the board and aligned with the former lines drawen on the inside of the fuse. When everything was lined up, I glued and clamped the structure in place and let it dry.

2/22/10

I inspected thefuse and found it straight and the glue dry. Notice that the technique used is to pin blocks over the plan so that the fuse sides were on the board and clapmped together by the blocks to hold position.

Next the sides were drawn together and the 1/4 x 1/2 tail stock was glued and clamped with med CA. The sides were bowed and that is OK at this stage.

The next step was to set thelower aft 1/2" triangle stock in place and make the sides straight by using a straight edge as I glured the triangle stock in place. The stock is tapered to match at the aft end.

I then turned th fuse over and put in the triangle stock on the top of the fuse. This serves the purpose of making the sides straight and to give a surface to glue the top of the fuse in place later on.

I inverted the fuse and fitted a 1/4" ply part to the inside of the fuse. This block was glued in place and will be the mount for the 1/4 - 20 nylon bolts that will hold the wing in place.

2/23/10

The session began with the equipment area of the fuse. It is easier to put in the servos now and avoid the tight quarters later on. I began with the rudder and elevator servos and they were mounted on Spruce rails in the rear of the compartment. Each will have an arm to the outside of the servo and each nyrod will cross to the other side of the fuse. This is done because

1. the nyrod needs a curve so that in hot weather the trim will not change on the surfaces due to expansion of the rod.

2. SInce there is a steerable nose gear, one of the rods must cross the fuse in order for them to be going the correct direction.

After the servos were in, I added a third rail for the throttle servo and drilled for the nyrod to line up with the motor.

The rear nyrods were then installed with a support in the middle to keep the rod from flexing under load. I filled the exit points so they can be sanded later.

The wing was next and I began the mounting process with a measurement of the center of the span of the wing marked on the leading edge. I then marked the center of the F2 former and lined up the lines. I improved the fit by sanding the fuse sides and making it fit.

I then set the fuse inverted on the table and put the wing in position with a weight to hold it. I made the wings flat by adjusting the fuse sides until the tips were the same height off of the table.

Next I set the tramble. It is the measurement of the wing being on straight. One tip must not be ahead of the other in flight. I put a string from the center of the rear of the fuse to the wing tip and made adjustments to make these equal on the two sides of the wing. I then marked the wing position on the fuse.

Next, I glued a reinforcement to the bottom of the wing where the bolts will go.

Then, I put the wing in position and drilled a 1/4" hole through the wing and through the ply mounting plate I glued in earlier. I installed a bold and blind nut and then drilled the second hole. With the wing in position, I put in the second bolt and blind nut. The wing is now in flight position.

I reinforced the fuse sides to reduce the damage to the wing when bolted to the fuse. I added other reinforcements in the nose of the plane.

I inverted the fuse and checked alignment. It is begriming to look like a plane.

Next I planked the rear bottom of the fuse and allowed the glue to dry.

3/1/10

The fuse bottom was rough shaped and then the nose gear linkage was constructed. As you can see below, I used a double ended ball joint so that the servo could drive the rudder linkage aft and the nose gear linkage forward from the same position on the servo arm. I made the linkage and tested it out to be sure it cleared

The linkage is 4-40 rod with a carbon fiber rod over it to make sure it will not flex under load.

The gas tank was then set so that the tank was in position and the plumbing was run to make the fuel system work.

I decided that a hatch in the nose area would be a good idea so I put the rails in place to make the hatch and fitted it to the area with balsa runners.

The corner will be rounded and this allows the hatch to fit inside the rounding. Mounting rails were then put in and the hatch fitted in the opening. Note that the hatch is made from thick balsa (1/4") so that I can shape the bottom any way it wants and the hatch will still fit properly. I spot glued the hatch in place and I will remove it later and add the bolts.

The rest of the nose consisted of the doubler for the engine compartment. I fitted the doublers so that they could be glued to the inside ply and to the motor mounts. This gives a solid install for the motor and allows us to seal it all up.

With the doublers glued in place, the nose area was rough shaped and prepared to be fuel proofed.

3/2/10

I turned my attention to the wing as it is mounted on the fuse and can now be processed the rest of the way through the build. I made the ailerons by cutting them to length, hinging them to the trailing edge with ca hinges and shaping the aileron to match the shape of the wing. I beveled the leading edge of the ailerons and checked them to be sure they were straight and had sufficient throw.

The wings then got the second sanding with 320 paper and a final fill on the imperfections in the surface. I used ca and light fiberglass cloth to strengthen the wing joint on the bottom of the wing. With the trailing edge ply and the fiberglass, the wing will be secure under any flight conditions.

I filled the fiberglass cloth and did a final sand to 600. this takes a lot of time and you are rewarded with a nice looking wing when you are done.

3/3/10

The wing was checked for finish and the covering began with the bottom of the wing. I cut the red covering on a flat table with a straight edge.

The covering was ironed on the tips and then on the straight edge just enough to cover the open area. I used one sheet for the entire wing and this will give the best covering job. Below you can see the ironing was done only about 1/2" in all the way around the edge of the sheet. The tips were left for later.

Above you can see the tip was stretched using the blower and the red was taken just past 1/2 way around the tip. The covering will do the entire tip, but I wanted the upper covering to be just past the center of the tip so that the joint will not show.

 

Below you can see the red panel after the heat shrink had pulled the covering tight. All the edges were rolled and sealed so that the top sheet will overlap the covering by 1/4".

Continuing on the bottom, I cut a strip of white and sealed it to the wing with the stripe located per the photo of Ed's plane. The stripe was sealed and ironed completely even though it is in the open span of the red.

The black was last and it was sealed to overlap the white by 1/4" and then wrap over the leading edge about 1/2 way.

The tips were completed and the covering was all set on the bottom. I then sealed the covering in the hatch areas and for the landing gear. The areas were then slit and the hatches were covered with the red material.

3/7/10

Next I covered the top of the wing with the red and the overlapped white. The white had a cured pattern on the original so I put that sort of design on the plane. The covering I do is usually done bottom of the wing first and then the top from the trailing edge up to the leading edge. The red was put on to cover all the open areas and the white overlapped as needed.

Next I put on the black in the center section and then the leading edge black was ironed in place.

The red stripes were put on last and then a coat of wax to help keep it clean and free of spots later on.

Next I put the top on the fuse as the interior is in place.

3/9/10

The fuse was cut to shape with a flat gouge and then sanded with 60 grit to rough shape and then with 120 and 300 grit to begin making the surface for covering. This is a time consuming process and is worth the effort in the final plane.

Next I filled the surfaces and painted the equipment compartment. This makes it look better and it hardens the surface of the compartment against fuel or other problems

Once the shape was established, I turned my attention to the stab.

The stab was rough shaped and now it was fine sanded. The elevators were shaped on the belt sander and then fine sanded. The bevel was added and the hinges cut in both sides. The elevators are joined by a piece of spring steel wire that runs between the elevators and is secured in each half. I bent the wire and drilled the holes in the elevators. The stab above was ready to mount on the plane.

I then indexed the plane on the work table. The blocks were adjusted so that the wing tips were an equal height off of the table. With the wings set flat to the table, I checked to confirm the fuse was square to the table and then began to set the stab.

After some cutting and fitting I glued the stab in place and allowed the epoxy to set up. The stab was set flat to the wings by sighting the stab tips to the wing surface while standing behind the plane. The tramble was set by measuring the stab top to the wing tip on each side.

Next I checked the rudder and fin and fitted it to the fuse. Once set up properly, I glued it in position being sure it was square and straight with the line of flight.

I confirmed the incidence measurements made earlier in the build. With the wing bolted in place, I set the frames on the wing and stab and checked the readings on each side of the fuse. The wing left side root is taken as 0 incidence so the other readings were

Left wing tip -.5 ----- ----cord 0 ---cord -.01 -----------------------tip -.4

 

stab tip +.22 ----cord +.1----cord +.1 ---------------tip +.18

 

These readings are a little different from the first ones and they are very nice. On this plane a reading of .75 degrees would be a concern for me.

The wing cords and the stab cord are all within .1 degrees and that is just great. The stab tips are fine with a little + incidence and it is not enough for the plane to notice. What you would look for here is that the stab tips should not have one + and one- incidence because that could add to .75 in a hurry.

The wing tips need some - incidence to keep them from stalling before the root would. This is called wash out and it is key to build that into the wing. We have about .5 degrees and that is Ok up to a reading of about 1.5 degrees. So all this is just fine and the plane will fly straight as a string.

I added the filler to make the farings for the rudder to stab joint and let it sit overnight.

3/10/10

The session was spent on covering. I did the under side of the stab and then the upper and the rudder all in white. The fillets from stab to rudder take time to get right and the small parts take a long time to cover.

next the black was applied to the left side and some of the red trim was put in place.

This is an unusually detailed color layout and since it was done on silk in the original plane, these colors were taped and painted on the silk. To make monokote do the same thing is very challenging in that it requires several layers of covering. If you have worked much with the material, you know it is hard to layer it. If it is not right, I just remove it and start again and that takes some time.

3/11/10

The covering continued with the completion of the stab and rudder

Next was the red top to the fuse. This was done with one sheet of covering and that takes lots of time and patience. The technique is to have an oversized sheet and iron it down at the bottom of the fuse sides and then shrink it repeatedly with the gun. There were wrinkles that were at the bottom of the fuse and I sealed the center area and trimmed off the red at 1/4" below the red and white joint line. The wrinkled part was cut off and discarded

Next the white stripe was applied and the red / white line was established in line with the rear black / white line.

3/13/10

The session began with the fuse side covering. I added the black and the stripes to finish the fuse covering as shown below

Next I covered the elevators and fitted the hinges to the stab

Below is a shot of the plane with the covering complete and the tail surfaces in place. The ailerons are glued on but the elevator and rudder will be glued on later as there is linkage to get ready first.

Another view of the plane shows the flag and other markings that are similar to Ed's plane from long ago.

Below you can see the shot of Ed's plane and above is Bill's. We were trying to be similar to the original and it looks like we made a pretty god show of it.

The under side of the plane shows a difference from the top and that should allow the pilot to identify the top and bottom in the air.

The covering has turned out well and a coat of wax improved the appearance quite a bit.

 

The rest of the session was spent making a rack for the fuse. With the covering on the plane, the danger of hanger rash becomes a big thing. The plane is built pretty light an,d therefore, the wood is soft and can be damaged. The rack will allow the fuse to be supported in an inverted status so I can put the equipment in the plane without hurting the finish on the top of the fuse.

Once the rack was constructed, it got a coat of paint and a second will be applied tomorrow so I can begin using it at once.

3/14/10

The rack was completed first thing and the fuse fit in it very well.

The next task was to begin the install of the equipment. The rudder and the nose gear were first and the linkage attached to the servo is shown below. It is a C/F rod over 4-40 rod to the nose gear so that it will not bend during use. The double ended connector also has nyrod that operated the rudder. Here is the trick THe rudder rod crosses over to the other side of the fuse. If you do not do this, the nose wheel will be opposite of the rudder and that is hard to fly.

Below you see the three servos and the rod going up to the nose gear. This was put in first and then the fuel system was attacked.

Below you can see the rods from the rudder on the left and the elevator servo on the right. The nyrod is supported every 4 " of length so it will not flex.

Next I started on the fuel system. The shot below is another KEY TRICK OF THE TRADE =- The line is the pickup inside the tank and it has a clunk on one end. The trick is to use metal tubing in the middle of the tube. If you land hard the clunk will not end up in the front of the tank. Ever had that happen ?? it will cause future dead sticks and that kills planes. ( By the way, I assume you know all of these tricks but I would not be doing my job if I did not mention what time has taught me at great expense)

The tank was assembled and the tubing run to the motor compartment. I find the tank MUST be removable for service and problem solving so I accomplished that as seen below.

The tank was placed on a foam pad and padded sides. There is then a hard wood strip that was padded with foam and screwed to the rails to clamp the tank in position. It is key that the tank not move ahead during flight as that will damage the tubing with obvious results.

The shot below shows the batteries padded in foam and placed in the bottom of the compartment . They will be held in by other things along the way. The electronic were completely hooked up and tested. Everything worked just fine and so I continued with the work at hand.

You will note above that I put the battery data on the inside of the plane so that when you are charging you will get the numbers right for the charger. If you have more than one plane this can be a problem.

Next I began the linkage in the wings. the servos were plugged in and the hatches removed to align the servo arms. I lock tited all the screws in the hatch so that it will not have to be dismantled again before the first flight.

Once the linkage was made and set up. I will drill the holes for the control horn. This makes life easy for the adjustments.

3/15/10

I began the session by mounting the control horns and adjusting the links to give centered ailerons. I will set the throws later.

As seen below, I then mounted the wheels on the main gears and mounted the gears in the wing. I checked the alignment and the wheels were tracking after some adjustment.

The rudder control hour was then put on the plane and the nyrod hooked up. The trick here is to use a 2-56 rod with a threaded end and cut off the rod with 1.5" of rod from the end of the threads. Then put the unthreaded end inside the nyrod and thread it into the inside of the rod. The threaded part sticking out will be for the quick link.

The switches are a problem on this plane as there is limited space in the sides and I just do not like having the switches show on the plane. I was looking for a cleaner way to do it and so I mounted them in the hatch behind the nose gear. This seems to be the best location and you can charge the plane while sitting in the rack. The switches will not show and will not see any gunk from the motor.

The elevator linkage went on next and the elevator was adjusted

I put the wheels on and tested the position of the plane. The slight negative incidence of the wing looked just right for the first flight.

The nose wheel was then painted white in the hub to improve the appearance some.

After the initial check of the CG showed it was close, I mounted the motor and hooked up the throttle linkage. I adjusted the throws for full open and closed positions.

This is a rear needle valve motor so I set it up for the motor test. You can see the fueler on the side of the plane and that is the easy way to fuel the plane. I will remove the line to the muffler as the overflow and reattach after the tank is full.

3/16/10

I set up the CG machine and adjusted the equipment to get the CG correct. The first flight will allow us to tune the CG. The record of changes made was entered in the book under setup.

 

I then set all the throws on all the surfaces with one rate on high and one on low. This makes the first flight a little safer. I checked the check sheet and ran the sheet for all the nuts and bolts to be sure they were tight and locktited properly.

 

I trimmed the canopy and the pilot ti fit on the plane and I cast pins in the head of the pilot so that it could be glued securely to the top of the fuse.

 

I removed the prop and painted it just for show.

3/17/10

I glued the pilot in place and allowed it to dry

The plane was done except for the canopy and the motor test. We are hoping to fly on Friday

4/1/10

With the tests done we went to the field. We checked the plane out and taxi tested the plane. Everything went well and then the nose gear failed because some set screws worked their way loose. We repaired that problem and the first few flights went very well.

 

We needed to adjust some up thrust in the motor to pass the thrust test and the other tests were very nice. We settled into some pattern flying and the plane looked good in the air.

 

Bill took the plane home and we were al pleased with the day in general