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Begin with the wings

The day began with the wings, as that just seems like to best place to begin. The plans were cut into a left and right wing and they were taped to the building board. I build both wings at once just for convenience. The plans were covered with wax paper and then a final study of the construction was done.

I got the materials together and laid out the ribs and checked their order and weight. I weighed the ribs for the two wings and made sure they were equal so that we will not have a heavy wing.

Everything looked in order so I began with the bottom hard wood spar and it was screwed to the building board with servo screws to be sure it is down flat and straight.

The ribs were trial fit and adjusted so that they were all straight. 4 of the ribs had a ply doublers for the landing gear plates and these were laminated to the ribs ahead of time. The ribs were then glued to the bottom spar and each was set straight to the plans and square to the board. They were all glued in place and checked The root rib is not set square and there is a template that tells the angle it should have. This is so that when the left and right are put together, the dihedral will be correct.

The balsa spars were then added in the front and rear of the air foil. The spars for the lower side of the wing will be put in at a later time, When all the spars were in the top the length was trimmed even with the first and last rib.

The planking on the leading edge is more than 4 inches wide so I edge glued 8 sheets so that there will be planking for all the panels.

There is a 1/8 x 1/4 stringer that is glued to the front of all the ribs aligned to the top face. The stringer was then cut to the angle of the top of the ribs.

Next the panels are glued to the leading edge starting with the spar. The planking is cut to size by dry fitting it to the wing and then glued with medium CA and secured to the spar so that the edge of the planking is in the middle of the spar. The Planking is then glued to the ribs and to the leading edge spar. I use a straight edge 48" long to push down on the planking and hold it to the ribs while the CA sets up.

Next the trailing edge spars are placed. These will become the structure for the ailerons and flaps so it is key to get them in place and straight. They can be put in with thin or medium CA however you prefer. The wing panels were getting quite strong and the next steps will add stiffness to the panels.

Once the spars were in place, the trailing edge planking was glued to the ribs and the spars. The top of the wings was then finished wy adding the planking on the center section, the tips and the cap strips. The top side of the wings were then complete.

 

 

 

The wings were then removed from the board and the root and tips were trimmed back to the ribs and sanded to give a precise finish to the ribs.

The landing gear support and plate was the first thing to consider on the bottom of the wings. the support was fitted into the wing and epoxied in place with the other ply parts.

The landing gear parts were drilled for the 6-32 machine screws that would be used to hold the gear in place. The plates were then cut from 1/4 ply and fitted into the opening formed by the reinforcements.

The plate was then drilled and had blind nuts imbedded in the back

After the alignment was checked the plates were glued in place. The feet were then removed from the bottom of the ribs and the spars were glued into the trailing edge area. This allowed for the bottom of the wing to be shaped and prepared for the planking.

The leading edge planking was cut to shape and installed on the wing. I cut a hole where the gear would be located that will allow for the aluminum gear to rest directly on the ply plate. You can see below that the planking covered 1/2 of the width of the spar and is glued to overlap the front spars on the leading edge of the wing.

Next the trailing edge planking was glued to the ribs just as the leading edge planking was earlier.

After the glue was set I sanded the trailing edge straight and glued on the trailing edge stock. This was done with white glue to be sure it will sand properly. Next I sanded the leading edge straight and applied balsa leading edge stock. The material supplied for most of the planking and the leading edge was too hard to use and it was replaced with reasonable material from my stock. The shot below shows the wings with the glue drying

The next item on the wings was to install the servo bays for the ailerons. I drew the aileron location on the wing and put the servo in the middle of the span of the aileron. I set 2 hardwood rails for mounting the servo with a rail under them for support.

After the glue set up I planked over the rails and cut a hole in the planking for the servo. The servo was test fit in the holes and all looked just fine.

I then completed the planking and cap strips on the bottom of the wing and glued on the wing tips. the wings were then rough constructed.

 

The next operation was to trim and cut on the wings to get them in rough shape. I do this with a carving gouge and some very very rough sandpaper. I have seen people use a small plane and even a hobby knife with some success. The point is to remove all the extra material and get to the general lines of the wing. I then go after the wing surface and do the first sanding of 4 that it will receive. This is with 80 grit paper and a block. I can not emphasis the block enough as this is the mistake I see people make the most often. With this rough paper you will sand waves in the wings for sure if there is no block. ( and not a little one --- 8" long minimum,) The second secret is long ---- long strokes with the grain. With practice you can straighten the surface as you sand.

Above are some shots of the roughed in wings. The leading edge and tips are left square to protect the surface from damage. I round it off and sand just before covering to give the surface the best chance of being ding free.

The wings should now be straight and all surfaces smooth. The trailing edge is the thinnest and therefore the one to check to be sure things are going right with the wings. See the shot below to illustrate what I mean.

The wings were weighed after roughing them in and the left wing was 17.8 oz while the right wing was 18 oz this is a good weight for wings this size and the changing of heavy wood has saved a total of 8 oz so far in the build. All airplanes fly better if they are lighter.

Next were the webs that fit between the spars and will greatly increase the strength of the wing even though they are only 1/16 balsa. the shot below shows the webs in place.

I then started on the ailerons. They are cut from the wing and then lined with wood to make them strong. I started by laying out the ailerons. and cutting a section out of the planking. The size of the section is equal to the tow balsa parts I will glue in later.

Once I cut a similar section out of the bottom of the wing, I cut the wing ribs and the ends of the aileron to free it from the wing. I then glued on 3/8 balsa on the leading edge of the aileron and the trailing edge of the wing.

I then glued balsa on the cut ends to square them off.

After the glue set up the wings were trimmed and rough shaped. The ailerons were shortened to fit in the opening in the wings. The ailerons were then fitted to the opening with clearance on each side. The hinges were drawn on the trailing edge of the wing and on the leading edge of the ailerons.

 

PUTTING THE WINGS TOGETHER

The situation is similar to the fuse problem in that the kit plans and the cut parts do not match and I would not use either method to hold the wings together. I had followed the kit cutter's plan and phoned them for clarification of their intended methods and did not get an acceptable answer on the structure.

I , therefore, decided to put the wings together in a way that is strong and light. I have used these techniques for years and have never had a problem with any of the built up wings. The process began by removing the planking on the top side of the center section of both wings. The dihedral brace is shown below and it is not long enough to supply strength to the wing. I made doublers for the brace from 1/16 ply and they extend the brace one full rib spacing on each side. This assembly was then fitted between the hard spars on the top and bottom of the left wing. This built up brace is as strong as a solid brace and considerably lighter.

Once the fit was good, I used epoxy to set the brace assembly in the left wing and allowed the assembly to dry. In the shot below you can see the dihedral brace and the side reinforcements. They are in position between the large hardwood spars.

The right wing was fitted to the brace and to the root rib of the left hand. This was then epoxied in place and allowed to dry. I then added braces as needed to complete the structure in the front of the wing.

In the photo above you can see the brace in position and the wings set at the dihedral called for in the plans. the 2 ply ribs are also glued together and that will help the strength.

At the trailing edge there needed to be structure for the wing bolts to secure the wing to the fuse. I removed the planking and made hard blocks for the first rib bay that fit tight to the planking on the top and bottom surfaces. With this in place, the bolts will have hard wood to grip and the blocks are tied to the main structure of the wing.

Once this was done the middle and trailing edge sections of the wing were planked .

The leading edge section was not planked because the two dowels that will pin the leading edge to the fuse must have some reinforcement if they are to stay in place for the long term. I will put blocks in the leading edge after the wing is fitted to the fuse the first time.

The wing joint on the fuse was rough cue and tested on the wing.

The joint with the wing was adjusted to fit without gaps and the incidence was then checked with the wing and the top of the fuse. The top line is the datum line and all the surfaces will be measured from that line. The incidence of the wing at the root should be 0 degrees on both sides of the fuse relative to the datum line. What is key here is that the wings be the same incidence on both sides of the fuse and that the stab be at the same incidence as the wings. the datum line is just a line to measure from. In the illustration below you see the setup for measuring the left wing root incidence. The bar is centered on the leading and trailing edge of the wing and the level measures the datum line and then the wing.

 

The readings were the same on both sides of the fuse, indicating the wings are straight and true. the Incidence relative to the datum line is - 2.4 degrees. The leading edge is low by 2.4 degrees and the plans call for 0 degrees. Checking the plans revealed another error in the drawings, as they show 0 degrees incidence on the wing and the stab, but the drawings produce the 2.4 degree angle with the datum line. While this is a huge error on the part of the designer, it is one that can be repaired in several ways.

1. Change the incidence of the wing by lowering the trailing edge or raising the leading edge.
2. Leave the wing and build the stab with the same incidence so the plane will fly perfectly.
3. leave the wing and stab and fly with some down elevator to compensate

The third choice is not acceptable because the plane must be straight and true. The first or second choice would work fine so I investigated the changes that would need to be made.

The wing adjustment would be to lower the trailing edge 1/2 inch which would ruin the lines of the fuse. Raising the leading edge 1/2 inch was not possible because of the internal structure.

Adjusting the stab would be 1/4" change to the trailing edge of the elevator and that change will be simple and invisible to make. With this decision made, I continued with the wing mounting process.

The leading edge of the wing will have dowels to hold the wing position. I set the wing with the center of the leading edge in the center of the fuse and drilled the dowel holes in the wing. I reinforced the leading edge with balsa blocks for the dowels to pass through. I did not glue in the dowels as that is done after covering.

Next is reset the wing and measured the tramble of the wing. By placing a pin in the back of the fuse on the center line, I measured from the back to the wing tip and adjusted the lengths to be the same. This ensured that one tip is not ahead of the other and we will do the same thing with the stab to be sure it is straight to the wing.

I then drilled holes through the trailing edge area of the wing and set 2 nylon bolts into the mounting plates in the fuse. I use blind mounting nuts in the plates as this will guarantee the threads will never strip out of fail. The nylon bolt is a little safety in a mishap as the wings will pop off it they are hit hard enough to cause the bolts to fail.

Above you see the under side of the fuse with the wing mounted. There will be faring's added to the wing to match the shape of the fuse, and I will wait to add them.

I then shaped the ailerons and the trailing edge of the wing. I cut the bevels in the ailerons and hinged them to the wing. I checked the throws and then drilled the holes for the dowels that will support the control horns

Once this was done, the wings got the second sanding and this was finer paper and all the corners were shaped and only one sanding remains before covering can begin.

The final building setup was to make the fuse farings for the under side of the wing. These were made while the wing was bolted to the fuse. The wood was glued to the wing and then shaped and sanded to match the fuse lines.

The final sanding was with 600 grit and all imperfections were corrected in preparation for covering.

Covering the wing began with the bottom of the wing and I covered the trailing edge faring in white. The flat areas of the wing would not allow the faring to be done with the same sheet as the rest of the wing.

Next I covered the inside corners of the ailerons openings. In the photo above you can see one of those corners. The way the covering large sheet of covering is cut, it is better to pre-cover the corners.

I then applied the white covering from the front spars to the trailing edge. The covering was trimmed and then head was applied to shrink the covering.

The white was applied to both sides of the wing and then the leading edge prep was done. I covered the leading edge faring in white to match the white that will be on the bottom of the fuse. I pre-covered the landing gear mounts as they are indented and would not cover in one sheet with the rest of the leading edge.

After the prep was done, I covered the leading edge and set the servos in the openings. The wires are easy to run before the top covering is applied. The bottom of the wing was inspected and re-shrunk where needed.

Next I began the covering ont he top of the wing. This is a complicated process that starts with the white on the trailing edge of the wing.

I marked the fuse sides on the white covering so that I could lay out the stripes. Below you can see the stripes set up to match what was on the original plane.

The stripes are in flight direction so they are not parallel to the fuse or the wing tip. I established a line from tip to tip that was straight and wet the stripes perpendicular to that line. I set the first stripe 1/2" from the leading edge of the wing and the second stripe at the wing tip. the other stripes were cut and positioned to have 8 red stripes and 8 white stripes all the same width.

Above is the right half of the wing with the stripes on. The ailerons are yet to be done. The left wing was done and then the leading edge was covered with the blue color and trimmed. Monokote works best if shrunk several times so I did that with 30 minutes between heatings.

The wing was really looking better and I continued to the stars. After studying the stars in the photos of Art's airplane, I selected a size that would look scale and cut each one out with the Xacto knife.

I positioned the stars ahead of time and then sealed them down to the blue panel. I let them cook and then sealed them a second time to be sure they were there to stay.

The next step was to prep the ailerons for covering. The hard points were glued into the ailerons at the proper position and I then drilled the top side for the head of the control horn bolt and then clearance drilled through the hard point. The ailerons were then finish sanded

The next step was to use the ailerons to identify the hinge holes in the trailing edge of the wing. The holes were opened up in the covering and sealed to the balsa. Once the surface was OK, I covered the ends and the bottom of the ailerons. The control horns were then threaded through the holes and some CA applied to the head of the bolts.

Once the control horns were in place, I covered the ailerons in white and hinged them to the wings. The red stripes were the next thing to work on and they were applied to match the stripes on the wings.

The final steps on the wing were to mount the servo arms and make the linkage for the ailerons. I glued the ailerons in place and then made up the links shown below

The links are made from ball joints, 4-40 allthread, c/f tube, and 4-40 nuts to hold the tube in place.

The links are best made once you can hook the servos up to the receiver that will be in the plane. The servos have soldered leads so there are no plugs to fail in the future. I left the leads long enough so that they will be easy to plug in with the plane in the holder. This process ensures that the recipe is correct and the linkage will not need further work.

I tuned the linkage and set the expo and rates in the transmitter. I locktited all bolts and nuts and the wing is complete.

This is a large wing and it will be prone to damage. I bought some fabric and made a wing bag to protect it. The lining is fleece and the outer material is more durable to withstand being handled and stored. The design allowed for the landing gears and it uses velcro to hold it in place.

 

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Stab Construction

The work on the stab began with setting the plans and wax paper on the building board and getting all of the materials together. The stab is build up and then planked with 1/16" balsa. this has been shown to be a strong way to do a stab and the design is very nice. What is not so nice is the wood selection as it is hard. I will replace most of the wood for the stab and that will save weight and not sacrifice strength.

First I framed up the stab using the plans and the wood I had in stock. Most of the joints were done with thin CA and checked to be sure they were strong.

Next I glued the skins to the frame and sanded them to proper shape.

The second side of the stab was glued in the same way and trimmed to size.

The elevators were framed next and then they were sanded so the trailing edge was thinner than the rest.

I then marked the hinge pattern on both elevators and drilled the holes for the hinges. The leading edge of the elevators were then beveled to allow the hinge to work.

Above you can see the hinged assembly after it was rough sanded and shaped. The throw was then adjusted by changing the bevels until the surfaces would be free to operate over a range of 45 degrees.

The control horns for the elevators will be bolt on and therefore I added plates that were inset in the bottom of the elevator. This will give a sturdy place to bolt the control horns.

The assembly was checked against the plans and it was put aside to be mounted on the fuse later on.

 

 

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Rudder Construction

The rudder plans were taped to the board and plastic covered just as before and the building material were located and checked. Some of the materials were too hard to use and I got more wood from my building stock. This problem is normal for any of the kit cutters. They are outstanding at the dimensional end of the business. The parts fit very well and all the wood is the proper size. The density of the wood is not one of their primary concerns and that is why I always advise people to get the short kit. The sticks and sheet product can be found with the proper hardness and the plane will be better and waaaaay lighter.

The fin was constructed and sized to the plans. It is made from 1/4 " material.

The fin is then planked on both sides with 1/16" balsa. This gives a string fin and I did the glue ups to produce the fine

The rudder was build from 3/8 and not sheeted. I made the rudder and waited for the fin to dry

I then shaped the rudder and the fin and as with the other parts, I left the edges square to protect the final shape from damage. The rudder and the fin has the hinge edges beveled and drilled for the robart hinges.

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Building the Fuse

The fuse construction began with lamination of the fuse skins. Since the plane is longer than the wood supplied, the sides were made from 3 cuts of 1/8 balsa. These were glued up with white glue and set to dry.

Once the sides were dry they were cut to shape from the plans. There were several errors in the plans and the cutting of the parts for the fuse and these problems made assembly unlikely as the plan was drawn. After a good deal of study, I concluded the fuse dimensions were correct but the internal structure was not going to work at all. I made changes to the plan so that the plane would go together and would be strong. the new plan will reduce the weight of the finished plane about 8 ounces and give a better strength level than the original.

I therefore set off building the fuse beginning with some pretty hard 1/4 square on the top of the fuse sides --- being sure to make a left and a right side. I have made 2 rights in the past and it makes assembly a larger challenge than is necessary. I then made side doublers that were 1/8 ply and covered from the front of the fuse to the trailing edge of the wing. That will add strength to the equipment box and is a standard way to build planes of this size.

 

I extended the fuse sides to in front of the normal front because there was an error in the manufacture of the cowl and it will not cover the fuse if the sides end at the F2 bulkhead. I allowed the sides to be long for now and deal with the cowl at a later time.

I set the servos for the elevators as it is easy to do it before the fuse is assembled. The servos were located and hard wood was set inside to ensure the servos stay where we want them.

After the sides were dry and checked, I glued in the first former (F2) and made it square to the side. This is the only former in the fuse that is square to the fuse sides, the rest are square to the center line of the plane.

Once the F2 was dry, I set the sides over the plan with the sides inverted ( the fuse is build up side down because of the flat upper stringers. The top will be built on later. I then put a block at the tail that made the sides parallel so that I could get the front of the fuse nice and square. After alignment, F2 was glued to the second side and everything was checked for square.

I then put in the balance of the formers being careful to keep the sides on the outer contour and square to the bench. This was allowed to set up so that the alignment could be preserved.

 

Next was the large triangle stock in the corners of the fuse. These were placed so that I can round the corners and begin to duplicate the oval shape the original chipmunk had. The blocks for the wing bolts were added at the same time.

The fuse then was in position to receive the wing. See the wing section for the process of mounting the wing.

Next was the rudder servo and the tail wheel. The rudder servo will be in the bottom of the fuse and the rudder will be driven by a shaft from the tail wheel bracket up to the rudder. All of this will need to be mounted in the bottom of the fuse. I started with the rudder servo mount as shown below.

The mount for the tail wheel bracket is ply and it must be square to the datum line. I cut and fit that plate in place

Next I turned the fuse over and set the upper side formers and the rails that are on the to of the fuse rail.

In the picture above, The stringers are added to the formers and the turtle deck is ready to plank, I will wait to do that as the mounts for the engine and some other items will be done before the turtle deck.

I installed the wire tube for the three servo wires and an ant anna tube that was let out the back of the fuse.

The bottom of the fuse could then be glued in place and the round corners could be cut and sanded. This was done and then the wing to fuse joint was completed. See the wing section for details.

The next step was to begin the cockpit by building some structure under the floor and then the cockpit floor could be put in.

The turtle deck was built from stringer and formers and the plans call for it to be sheeted. I debated leaving the sheeting off to save the weight as the structure is sufficient to fly as it was. Since the plane will be handled by holding it in the area of the turtle deck, I decided to plank it so that it would not flex if you were holding the plane by the turtle deck during and engine test.

The structure was ready to plank, so I selected some very soft wood and cut it to the size needed. I soaked the wood in water to make it conform to the structure and glued it in place on the frame.

Once the planking was done, I carved and sanded the surfaces so that the correct shape was produced.

The tail assembly was next and there are faring blocks that fit between the rudder fin and the stab. These blocks can be tricky to shape so I make them before I assemble the tail. the process began with the realization that the rudder and the stab are 3/8" thick so I made a jig that had stab material and rudder material glued at 90 degrees.

The blocks were then tack glued to the jig

The completed jig was then tack glued to the back of the fuse so that the rudder block was in the center just as the rudder will be later.

I then cut,carved and sanded the blocks to the correct shape while cutting the jig.

Above you can see what the assembly looked like before sanding. I sanded it and then slit the tack glued spots to set the jug and the blocks free from the fuse.

You can see that the blocks were then the perfect shape and the construction of the tail assembly could continue.

I lined up the stab being careful to get it on straight and to position it so that the rudder and the blocks would all fit.

Once this was done, I glued the stab in place and confirmed the position.

The rod that will drive the rudder passes down through the fuse and is also the tail wheel rod. The tail wheel bracket supplied by Glen will work just fine but the rod is not long enough to do the the job. I replaced the rod and bent the angles in it to suit the needs of the plane.

I began with a 90 degree bend in the 1/8" rod to pass into the rudder frame. I then drilled a hole down trough the fuse so that the rod could pass from the rudder straight down to the tail wheel bracket. I marked the rod and made the first bend for the tail wheel area. I then made all the other bends.

Above you can see the finished mechanism. It has tubing over the upper part so that I can block it in place without hurting the rotation of the shaft. There are various collars and a steering arm that will be powered by a servo. The steering arm rides in a flat spot cut in the rod that will ensure the arm will not slop on the shaft. There is a tail bracket that will be bolted to the ply plate on the bottom of the plane, and the lower section is for the tail wheel.

The problem is assembly as this assembly will not go in place after the rudder fin is glued in. I decided to place the linkage loosely and glue up the rudder fin.

Above is a photo of the rudder glued in place. The fin must be straight to the line of flight and perpendicular to the stab. The linkage for the operation of the rudder must also be in the correct position, so I assembled all the parts and put glue on the fin and on the blocks that support the fin. Everything was checked and allowed to dry. For this sort of operation, I use 30 min epoxy and I have time to adjust whatever needs it, The 30 min set up time in important so that I have time to get everything in place.

The rudder and the elevators are not glued in until the covering is on them, but I use them to be sure the position of the other parts will work with the overall design.

Once the glue dried, I removed the elevators and the rudder and secured the brass tubing around the rudder control rod so that there will be no motion after the plane lands lots of times. I epoxied a block to the tube and the inside of the fuse.

Once that was done, I completed the construction of the back of the fuse. There are 2 additional faring blocks for under the rudder and they were put in and all the farings and radii were shaped and sanded. The dorsal fin was then glued in and a final coat of filler was applied and allowed to dry.

The muffler arrived from the fine folks at Bisson and it will fit just fine on the plane. I started with the front of the fuse with the extended length in front of the F2 former.

I fit the gas tank into the motor box, after getting all the plumbing done. The tank is padded so that the gas will not foam. I completed the structure of the motor box and checked it for downthrust and right thrust. All the main joints were reinforced with hard wood and the motor was ready to put on the plane.

The shot below shows the fuel system with lines for fill and for overflow.

I then mounted the motor on the firewall. I set the bolts since the engine is on for good.

The fuel tube to the carb was run and the alignment of the motor was confirmed and the data written in the book.

Below you can see the cowl in nearly the correct position and the formers that will make the top deck of the plane. Since there will be mounting blocks behind the F2 former, it is good to fit the cowl in rough position before planking the top deck.

The photo below shows the front view of the cowl being fitted to the plane. I tend to cut and fit several times to avoid cutting too much. The cowl would not go on all the way because the fly wheel on the engine was hitting the inside of the cowl.

Below is a photo of the cowl and you can see the fly wheel through the fiberglass.

As you can see above, the cowl was not all the way in position as it needed to move 1/4" aft and it was hitting the fly wheel. There were no options for this situation as the spinner alignment would be compromised if I moved the motor.

The solution was to convert the motor to battery ignition and several things changed.

• The fly wheel is over an inch smaller on the new ignition system so the cowl will fit just fine and the big problem will be solved
• The change will save several ozs even with the added battery - which can be placed on the CG.
• The motor will run better with the electronic ignition.
• It will start better
• The automatic timing advance will be good to have

 

I ordered the parts from C& H ignition as they are one of our best suppliers.

While I waited for the parts, I returned to the tail assembly and final sanded all parts to prepare for covering. I began with the white on the bottom of the stab and the fuse. The covering seen below was completed by finishing the stab.

The next step was to put the red on the top of the stab and the white on the fin. The fin would get all three colors, but the white was just the first of the day. The red was ironed on the side of the dorsal fin as the fin will be blue.

After completing the other stab and attaching the elevator and rudder, the colors began to come together.

The next part was to add the blue to the dorsal and the fin.

The fin and rudder then got the red stripes and a star on the top.

I put some white around the red so that as I cover the fuse sides the line will stay straight and clean. In some areas the covering is 3 layers deep and all of this takes a lot of time to do properly. This covering represents 8 hours work.

Next I put the servos in the locations that were built before. They were mounted down and wires run to the front of the plane.

The arms were bolted on with the equipment turned on so that I could center the arms. These are aluminum arms with a lock on them.

Above you can see the control horns were on and the links were constructed and adjusted so that all surfaces worked. I mounted the tail wheel bracket in place and put the tail wheel on the shaft. The plane was then assembled and all surfaces tested for proper operation.

Next the equipment compartment was designed and constructed. It was sealed off so that no air from outside could enter the fuse and then rails were glued in place to hold a board. The throttle servo, receiver and batteries will be on the board. This will make service easy and convenient while the appearance will be up to Glen's standards.

Once I was satisfied with the design, I masked off the fuse and painted the inside of the compartment.

Next the top deck could be done. First, the blocks for mounting the cowl were put in place and the stringers were glued in the notches. The structure for the cockpit was constructed at the same time with hard wood rails to hold the canopy retaining screws. This required planning so that the screws were not in balsa.

After completing the structure, the deck and sides below the canopy were planked and then sanded to shape.

The cowl was roughed in and the cowl was positioned in the approximate location. Everything was confirmed to fit, so I continued to the cockpit and completed the structure. You can see in the photo below that the faint vertical like was the end of the fuse sides on the plan. I extended the fuse sides so that the cowl would fit over the sides. After the motor is upgraded and the cowl if fit to the spinner, the back edge of the cowl will be straightened and it will be mounted to the fuse using the hard wood blocks installed earlier.

The nose was reinforced with hard wood and screws to increase the strength of the fire wall area. I used aeropoxy glue for this work as it is the best product I have ever worked with.

In the photo above you can see the screws and also the overboard discharge for the gas system. It is key to get the fuel safely out of the plane and away from the heat of the motor.

 

With the hub on the motor, I fit the cowl to the plane and positioned it with button head screws into the hard wood blocks under the planking. I made holes for the intake, the exhaust ports, the air flow into the cowl and the carb adjustment screws. As I fit the spinner back to the cowl I noticed the face of the cowl was at a different angle than the spinner back. In addition to being the wrong size, the cowl face was cast at the wrong angle. This can be fixed by putting a ply shim on the front of the cowl that is tapered to make the cowl match the spinner back. Below is the shim I used.

If you look you can see that it is tapered to correct the problem. I glued it securely to the front of the cowl with Aeropoxy ( nothing else would hold it) and let it dry overnight. I then used bondo and body filler to make the lines match so that the change would not show on the finished cowl

When everything fit properly, I sanded the surface to 320 grit and primed the first coat on the cowl

The landing gear and the wheel pants got their first coat of primer as well.

The equipment was then set in the plane in final position and the batteries were placed on the board temporarily to check the CG. All the parts of the plane were attached and the CG checked very well for the first try. This is a real big thing as I will not have to move equipment around to get the balance straight. The plane is not done, so there will be a final check of the CG after paint and the rest of the covering is in place.

The equipment was then mounted on the board and the board fitted into the fuse. The final assembly will happen after the covering is on the fuse.

Next I addressed the canopy fit to the fuse. The front and rear of the canopy will hit the fuse at a sharp angle that will make holding it on the plane a challenge. Since there is no hatch to get into the cockpit area, we decided to hold the canopy on with button head screws after it is painted. In order to make this work well, I built a saddle for the canopy to fit into. This was done with strips of 1/16 hard balsa that were glued on the fuse top in layers to build up a curved ridge. I then carved the strips to get a good fit on the canopy.

Once this was done, I masked the area off and painted the area inside the canopy the same as the cockpit. this will give the appearance we are looking for and the ridge will give material to seal the cowl to the plane. The screws will pass through the ridge and enter the hard points under the planking and that will give the system longevity.

Next was the issue of mounting the canopy to the fuse. I needed to do this before paint as I did not want to be drilling on the painted canopy. I located the hard blocks under the planking with a pin and marked the screw locations on the ridge. I positioned the canopy and began drilling and shooting the screws so that the entire edge of the canopy was secured to the fuse.

After removing the canopy, the final sanding of the remaining fuse was done and covering the fuse was next on the list. The white covering was put on first with care to make the area under the edge of the canopy covered with the white monokote since the paint on the canopy will be white around the edges

Once the white was on, I put the red top deck on and the covering on the plane was complete. The insignias were next to go on and they looked very nice.

I then cut holes in the covering for the switches and fuel port and installed the equipment in the final form. The ignition module was placed inside the fuse with padding to prevent vibration from affecting the system. The other components were mounted on the board and wires were secured to prevent damage from vibration and to improve the appearance of the equipment area.

 

 

Mounting the engine

The first step on the engine was to add the throttle linkage to the side of the motor. The throttle arm moves in an unacceptable direction and Glen purchased a linkage kit from B&B to correct the problem and orient the linkage in a direction we can deal with easily. Below is a shot of the linkage after the drilling and adjusting was done

 

Next I inspected the plans and found the down thrust is 1.5 degrees and it is built into the fire wall. It also has 1.5 degrees of right thrust that is not in the firewall so it had to be done with a shim

The first step was to make the motor box from the ply parts. The cowl must fit and therefore I measured the length of the motor from the spinner back to the motor mounts and allowed for the shims. This engine is slightly longer than the one designed for the plane, so I changed the dimensions of the motor box. As shown below, I drew the firewall on the plans.

The firewall was then set up for the motor by finding the thrust line and the center of the wall. Because of the right thrust, the motor had to be moved left so that the spinner will come out in the center of the plane and line up with the cowl.

You can see above that the center line was moved 3/16" to the right looking at the front of the firewall. The mounting holes were then drilled and the motor checked to the holes

Next the ship was made to give the right thrust. This is simple to do with the digital level as the fire wall is set to zero degrees and a shim is glued to the right side ( airplane's left). The motor was then set on the firewall and the angle adjusted to 1.5 degrees.

The shot below shows the measurement after adjustments were made.

the motor box was then glued up with all sides square and the motor box bottom was glued in.

The motor box was tested in position and everything looks good to go once I have the motor and muffler in position.

Reinforcements were glued in place and the assembly was set aside for the engine and muffler to be check mounted before final assembly.

Once the motor was mounted on the plane, it was discovered that the fly wheel at the top of the photo below hit the inside of the cowl. The solution was to convert the motor to electronic ignition, as that has a small flywheel. I removed the motor from the plane to make the conversion and the first step was to secure the muffler to the engine head.

Above you see the finished muffler mount. The bolts were converted to Stainless due to the heat and corrosion the mount will see in the future. I drilled the bolts for the aircraft wire and secured the muffler to the engine with locktite.

There is a very specific way to wire the bolts so that they do not come loose later. I used a double strand of Stainless wire and it was passed through the bolts and braided against itself to ensure longevity.

next was the conversion to electronic ignition.

The parts arrived and I set about getting the upgrade done. The parts did not fit together at all and, since C & H has always had great parts and instructions, I knew there was a problem. I discussed the situation with Terry at C & H and he decided that the engine was made as Quatra was shutting down the Canadian operation. In 15 years of upgrading Quadras, he has only seen one other motor like this one. It is made from parts from other size motors and it was a good motor un till we tried to put the oversized fly wheel in the chipmunk and then upgrade. After he thought it out, he decided that I will modify the mounting bracket for the sensor and he will send a different hub and a new sensor. These changes will put us back in good shape to set the ignition up. Parts will arrive soon and the upgrade will be a success.

With the engine converted part of the way, I could mount it on the plane for good and begin the other work on the fuse. I put the switches and fuel port in place and fitted the cowl part of the way on the nose. I marked the location of the hardwood mounting blocks for the cowl.

The rest of the cowl process will wait for the engine rebuild.

The Engine sensor was replaced and the timing was set per the instructions from C &H. A shot ot the setup is shown below. The timing was set at 28 degrees before top dead center.

The plane was assembled and the motor started after some setting of the mixture screws. I ran three tanks of gas at various speeds and the motor began to smooth out and run well. I set the high needle for best RPM. the needles will need to be reset after about 2 gal of fule is run through the motor.

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Equipment Installation

The servos were set in the wings and the receiver was attached to line up the links and be sure the ailerons worked properly. I soldered the extensions in place as I do not like plugs hidden inside the plane.

Next the 2 elevator servos and the rudder servo were wired with soldered extensions to reach the receiver.

With the conversion of the engine to electronic ignition, the smart fly switch was ordered and wired to confirm it would operate as planned. It uses a fiber optic line from the receiver area up to the front of the plane. This is the best system I know of to control the engine and not risk any interference with the systems onboard. I hooked up the switches and tested them for proper operation.

The engine was mounted for good and lock tite was placed on all the bolts. The fuel system was set and the fuel intake and switch locations were cut through the fuse side

I made an equipment board to hold the batteries, servo,receiver and other equipment. It was painted white and mounted to the plane. The equipment was then tested for operation and the batteries strapped down to prepare for the first CG check

The throttle servo was placed on the board and the linkage run to the motor

The other components on the board will be set later. The throttle was hooked up tot he motor and adjusted for function

 

 

 

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Balance and Weight

There are several things that need to be done as the plane nears completion.

1. center of gravety must be correct and adjustable for the future.

I tested the CG while the covering was mostly on the plane and it was in the zone. Second test was after the paint was done and again everything was fine.

2. horizontal balance must be correct

First check showed a leavy left wing. This will be confirmed later on and corrected

3. total weight will be recorded in the book

 

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Assembly of the plane

The first of many assemblies was done to check the alignment and position of the tail surfaces.

I made adjustments to the surfaces and they were in good shape. I will wait to glue them on as there are some other steps that need to be done first.

The next assembly was after the fuse was completed and the cockpit was constructed.

Final steps

The first final step was to build a holder for the fuse. The plane will be assembled and serviced from an inverted position and that makes a holder of some kind a requirement. I used the side view and top view of the fuse to determine the proper size of the holder so that the nose and the rudder will clear the surface the holder would be sitting on. After the design was done, I began the construction with some nice birch ply and cut out the parts with the proper shape. the cutouts for the fuse will be lined with foam to avoid damage to the plane so the size of the openings took that into account. Aft of the canopy is a dorsal fin that must not be damaged when the plane is in the holder, so I made a deeper cut in the shape of the holder to allow for the fin and the foam lining.

The holder was then assembled and sanded and filled to make the surface presentable. The inside will have storage space that will be handy for the things that will go with the plane.

The holder was then primed, sanded and the first coat of semi gloss was added.

The wheel pants were next and I began with the landing gears on the wing. As you can see below, the bending of the gear was not close to the correct angle. The wheels should be close to perpendicular with the ground.

You can see that the wheels are not in the correct line so I removed and landing gears and re fabricated them. This process did involve a large hammer and some language normally heard on a golf course. Below you see the result.

The gear still has some angle to it but this will work just fine. I then started with the wheel pants by laying out the wheel position on the inside of the pants. I have had some real success making one left and one right pant so I thought I would do that here too. I glued a block to the inside of the pants as shown below

I used clamps and let it dry before drilling for the wheel shaft. The plane was then set on its feet for the first time and the gear was checked for alignment. The pants were then marked for position on the gear.

The block for the outside of the pants was then glued in place after a hole was drilled.

Above you can see that the shaft will pass through one side and into the block on the other side of the pant. This will make it secure for a long time to come.

The next step was to line up mounting holes with the wheels assembled. The holes were then drilled in the gear so that they would hit the ply blocks on the inside of the pants.

The pants were then assembled and lined up parallel with the ground and the holes were drilled into the pants. The blind nuts were then set in the blocks that would hold them to the gear.

The assembly was then put back together and everything checked for proper alignment. Everything looked good so I disassembled the parts and gave everything a sanding to get set for the primer coat of paint.

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