Workshop

Oct 19,2008

Brent and I went to the field for the second try at flying the Cap. We assembled the plane and ran all the checks to prep the plane. We started up the Da-85 and were again impressed with the power and the sound it puts out on demand. After the engine was warmed and the range check performed the plane was ready to go. In the warm up the spinner bolt, which had an extension on it, failed and the spinner was set free. Since I do not carry spare spinners, we decided to fly without the spinner and realize that the plane will be slightly tail heavy from the original settings. The big mill was then let loose and the plane took to the air at less than 1/2 throttle and I climbed for altitude and leveled it off to find the trim was close to correct. I always put in a few clicks of up trim for a new plane to help it in the first few seconds of flight and this time it made the plane climb a little more than was comfortable. several bumps of down trim and she was flying along at 1/2 throttle with authority and it looked nice in the air. The plane was very sensitive to elevator and a check of the CG by inverting the plane revealed it was tail heavy enough to account for the sensitivity I was seeing in the plane. All else was looking good and there was no lack of brute force from the engine.

Brent took over the plane understanding it was tail heavy and did a superlative job flying it and made a nice job of a very tricky landing. We adjusted the position of the batteries and tuned a few other small things and Brent took of for the second flight to find a big improvement in the behavior of the plane. It flew very well and the inverted test indicated the CG should move a little more to the front. I like to set up a plane so that if it is trimmed properly, the inverted flight takes just a bit of down to fly level. We ran other trim tests and she flew right through the tests with no problems.

The second landing was a sight to behold and even the critical onlooker had to admit that it was well done. We made some further adjustments and the third flight hit the CG right where is belongs. We then made a list of things to adjust and folded up shop very pleased with the day and excited to make the changes and put some more time on the plane.

Oct 16,2008

Brent and I went to the field to fly the plane and encountered a problem with the electrical system on the engine. This seems unbelievable since we engine tested the plane three days ago and everything ran just fine. We did not adjust or change anything on the plane since the engine test and therefore expected everything to run fine. Upon investigation back at the shop and discussion with the DA service people, the ignition module was bad and the DA people said this will happen about one in one thousand motors they send out. I believe this bad luck is attributable to Ramone and his deviant life style. They will send a new module and it will likely be here by the time the weather clears and our schedule allows to go to the field and try it again.

Oct 13. 2008

Today the plane was completed. The second coat of color on the upper cowl was dry and the final assembly and checklists were done. Below are some shots of the plane. We will be flying in later in the week and this file will then be updated.

Oct 12, 2008

The day began with a list of things needed to finish the plane. These were then organized and the list was used as a guide for the day.

Wheel pants were checked and mounted to the gear and the gear was set on the fuse for the final time.

The opti switch on the ignition was wired and checked for proper function. The tail surfaces were hinged on the fuse and linkage made and adjusted. The surfaces were then programmed and rates set according to the plans. The cowl was mounted and the spinner was shimmed to provide clearance. The motor box wall behind the carb was glued in place and the motor box closed up. The new prop was drilled and the spinner and prop set on the plane.

Once the plane was assembled, the center of gravity was checked and adjusted to the plans. The equipment and batteries were then secured and the engine test was run. The motor ran very well and the RPMs were 6400 with the 26 x 10 prop.

The final steps were done per the check sheet and all was ready for the first flight. At the end of the day, the cowl upper was sanded and a second coat of color was applied to improve the finish.

Oct 11,2008

Part of the day was spent at the Mack Hodges fall fly-in which is an annual event that gathers flyers from all over the country.

The wheel pants were installed on the gear and then removed and painted. The upper cowl had the primer sanded and the color coat applied so that it could dry overnight. More time was spent on the wiring and some of the batteries were charged.

Oct 10, 2008

I have had the plane for a month and this day was productive. It will be ready to fly very soon and we are excited to see it go well.

The fuse covering was the first order of business and it was completed by adding the white stripe and the blue on the bottom. All black striping was then added and the entire plane inspected to be sure the covering was in order.

The assembly of equipment could then begin with the servos in the rear. String has been built into the stab and routed down to a tube that carries the wire to the equipment section. The servo wires were extended by using solder and heat shrink tubing. The string was used to pull the wires and this was done with great difficulty as some of the corners the wire had to turn were a little tight in the stab area. Having done this part the servos were mounted and tested for operation with the fly board and the receiver.

the throttle and choke servos were then wired and checked for operation. The wires were made into cables to avoid vibration damage.

Oct 9, 2008

Since the fuse is complete, the covering was the order of the day. I began with a fine sanding and inspection of the surface. I used 320 paper for the final sanding and I sand one panel and then cover it. In addition to the finish on the panel, I am care full about dust and dirt on the surface as that will make the covering look bad.

The color scheme is determined before the start of the covering and the lines were drawn on the surfaces. This layout of colors allowed the green / white line on the fuse to be lined up with the upper and lower cowl. This will simplify the painting operation

The under side of the stabs and elevators were first and then the top side. With the stripes on the upper surface, this process takes a lot of time. On to the rudder and fin and they were covered and checked for the line between the green and the white. All 3 surfaces had the control post added and secured at this time and the hole filled on the upper surface.

The fuse between the stab and rudder was then covered and the turtle deck was done in green and trimmed back to the line on the fuse.

Oct 8, 2008

The day began with the upper hatch as the shape was ready to be determined. I cut the extra wood from the sides and fitted it to the cowl. The 1/8" front wall was then glued in place and after the glue was dry the spacing between the upper hatch and the rear wall of the upper cowl was set at 1/16". The rest of the surface was rough sanded and I was ready to move on to the pilot area.

I have a nice dash panel that will fit with some coaxing and Brent intends to have a pilot figure in the cockpit so there has to be a floor that will allow enough height. The dash panel was cut down to fit between the rails and I soon figured out that the floor was not going to go in with the design I had in the mornIng. I glued in interior rails that will fit inside the fuse ledge and that solved the floor problem. After installation of the floor I build a trap door that will serve the needs of the cockpit in the future. Reinforcements were placed and the overall shape of the hatch was confirmed with everything tightened down to the plane.

Next I completed the sanding of the cowl upper and lower and cleaned both halves. Inspection of the cowl determined it was time to prime the parts and then sand them down and see what the look like. I used a good dupli-color primer and put two light coats on all the surfaces.

I began working on the wheel pants by assembling the gear assembly and fitting a 1/4" ply plate on the inside of each pant. This plate was set in epoxy and allowed to dry.

Oct 7, 2008

The upper hatch was the focus of the work for the day due to some engineering problems fitting the classy control panel into the limited space in the pilot area. The rough construction was shaped to match the cowl and cut down in the pilot area. The control panel was fabricated to fit over the rails and down to the level the floor would be placed. This required considerable time and gave a nice fit behind the 1/8" sheet glued on the foam face of the cockpit. The floor was then constructed over some hardwood rails that were 3/16" thick. The trap door will allow the pilot to be added and it was constructed to complete the upper hatch assembly.

Since the cowl is complete, it was time to prep it for paint by straightening up all the cut lines and washing the mold release off of the outer surface. The entire thing was then sanded with 220 grit and any imperfections filled with bondo. This was then set to dry

The elevators are all glued up and shaped and now need a little increased strength so that the counterbalance will be strong. I drilled from the tip into the balsa leading edge material and glued in some small dowel material to pin the two parts together.

Oct 6, 2008

 

Work continued on the upper hatch by laying out the foam front upper for cutting to size so that it would fit between the hard rails.

The foam was then glued into the frame and additional balsa glued in to fill in the edge of the area.

Oct 1 - 5, 2008

There is considerable work done on the cowl and it is in fine shape. The process includes many steps that I find useful to get this type of cowl in place properly. You will notice that I have not done any work on the upper hatch as that will wait until the cowl upper and lower are in final position. The most important joint on the plane is the upper cowl to hatch joint as that is the first thing you see as you look at the plane. This needs to be very nice and my approach is to get the cowl done and then match the upper hatch to the cowl. I do this because the most important thing about the cowl is the joint with the back of the spinner and one can not effectively set the cowl to satisfy both joints at once.

First setup was to mount the lower cowl in position with the back of the spinner. This is accomplished by using servo screws to set the cowl to fuse joint and hold the lower cowl in position while the spinner joint is inspected. There were a total of three adjustments to the position of the lower before I was satisfied that it was OK. The lower is glued to the ply face that is bolted to the under side of the motor box. I bolt it in position and then check the shape to be sure it is in contact with the inside of the cowl lower. When all this was OK I glued the lower to the ply facing and allowed it to dry

Second step is to fit the upper to the lower and install button head cap screws to hold the upper to the lower. This is done with blind nuts in ply that is glued to the inside of the cowl and the upper is bolted to the lower.

Third is to mount the upper ply facing to the top of the motor box and fit the cowl upper to the ply face. When it is right the glue is put to it and allowed to dry.

ON each step I checked the spinner joint and it remained straight and true.

After all that work, the cowl is in final position and I began matching the upper hatch to the rear surface of the upper cowl. First I began to build the upper hatch frame with four 5/8" dowel sections that had been drilled for center of an 8-32 bolt and countersunk to the depth of the head of a cap screw.

These four sections were mounted in the fuse sides and ply ears were made with blind nuts in them.

The ears were mounted with the bolts and the side frame was cut from hard wood. The ears are glued and pinned to the rails and cross members are glued in place to give the frame the needed strength to withstand the vibration of flight and the repetition of putting the plane together for years.

 

 

September29 - 30, 2008

Good progress on the fuse! The decision was made to make the rudder to fuse joint scale and leave it squared off. In order to get the strength up to acceptable levels, I set two ply formers in the rear of the fuse and then glued in a c/f rod up into the rudder to ensure it would stand the stress of Brent's high speed knife edge passes low to the field. This completes the tail section and final sanding and covering is next.

The front end of the fuse had the motor on it and there are now many things that need to be done. I began the cowl prep by fitting the lower half to the fire wall and positioning it to make the spinner come out just right. The lower half it put in place with a plate that is bolted to the fire wall under the motor box.

This plate was fitted to the fuse and positioned on the cowl. With everything in position, the lower half was glued to the plate and allowed to dry.

Next the lower was removed and the structure could then be made beginning with the bottom of the motor box and some strengthen blocks to secure the fire wall in place. Once all the blocks were in place and dry, I pinned all the joints in the front for added strength.

The rear carb needs to have at least one inch of open space to function properly, so it was then time to establish the position of the equipment in the front without violating the space requirement of the carb. I began with the ignition module and it was soft mounted to the side of the fuse and wires run to the engine. The throttle and choke servos were a substantial problem as the linkage is in the carb compartment and the servos need to be aft enough to get out of the area of the carb.

After due consideration, the servos were mounted and the linkage run to the engine. Though we were intending to use a mini servo for the choke, the demands of space made a full size servo work better. I installed a servo I had in stock and the problem was solved. The final install will wait for more of the work on the front.

September28, 2008

The new motor was mounted on the fire wall today and it has the 2 degrees of right thrust that the plans call for. It is key to have the side thrust and not down thrust. The right thrust counteracts the torque of the engine and lets you pull to an up line without standing on the rudder to keep it straight.

Once the motor was mounted on the fire wall with the 2 degrees I mounted the fire wall to the plane and began the process of strengthening the joints with hard wood and wood pins. The cowl is in upper and lower parts and the lower was fitted to the plane and cut out for the engine and muffler. It is key to have the cowl fit to the plane so that it is straight and the spinner is aligned correctly. This step takes time and it was nearly complete at the end of the session.

I joined the owner of the Cap for some great flying at the Alex City field and he graciously made room in his hanger for the new plane

September 24- 27, 2008

These were partial days in the shop and progress was made on the shape and finish of the fuse. The tail assembly is now complete and only fine sanding is required to begin covering.

The beautiful mill from DA arrived and it is a work of art. It is a single cylinder motor with a rear carb. I have elected to mount it on the firewall without standoffs as that is DA's method. The firewall was cut to shape and the engine mounted with a 2 degree right thrust correction. This is done by mounting it on the fire wall and then checking the thrust with the digital level.

September23, 2008

 

The day began with the plane assembled to check for problems. The wings were then finished

by adding striping and hinging the ailerons to the wing. The servo linkage was then constructed and tested. For details on the linkage construction, see tips and tricks in the main menu. This completes the wings and leads to the completion of the tail surfaces.

Completed the glue-up of all the surfaces and final shaping will be all that is left to do on the back of the plane. Test fitted the canopy and developed a plan for making the upper hatch.

Hope for delivery of the big DA tomorrow

September 21, 2008

 

We continue to wait for the Da 85 so the front of the plane is not complete. The wings have the servos in them and are ready to be striped and hinged.

The fuse got the stab in place and it was secured with additional blocking and pins into the frame. The rudder was fitted to the fuse and additional wood was glued to the front of the rudder.

The turtle deck was fitted to the fuse and the foam hollowed out to save weight.

The turtle deck was then glued in place and the front facing of the turtle deck was planked with 1/16 balsa. The fuse then was rough sanded and shaped in preparation for covering.

The fuse from the leading edge of the wing to the tail is nearly done and covering will soon begin on the fuse.

September 19, 2008

 

Today I began with the incidence on the wings. The first step was to decide the location of the two pins that were set in the wing root and go through the fuse sides to hold the position of the wings in flight. The third pin is a 1/4 - 20 bolt that is attached in the wing root and will be used to hold the wing root securely to the fuse sides. These three items were set in large hard dowels in the wing root. First I drilled the wing root and then used epoxy to glue the large dowels into the wing root. After the glue was set, I drilled the dowels for the pins and bolts and installed short pins.

The incidence of the wings was set to 0 degrees to the datum line on the fuse. Carden makes this easy by making the datum line the top surface of the fuse. I used an electronic level to set the angle of the wings to the same as the datum line. The level sets to one tenth of a degree and when I had the correct reading I superglued a block under the trailing edge of the wing so that I know where the wing belongs.

With the short pins in place, I slid the wings on the wing tube and pressed them against the fuse sides with the trailing edge on the blocks for alignment. This process marks the location of the holes in the fuse and next I drilled holes for the pins and bolts. Once the wings were on and aligned, I made and glued in ply doublers in the inside of the fuse to hold the pins under the load of flight maneuvers. With all the glue dry, I bolted the wings on and did one final check of the alignment to find there is a .1 degree variance between the wings.

This data was entered in the setup sheet for future reference. The tramble was also confirmed and recorded in the book. The final step was to glue in the phenolic wing tube in the fuse with the wings bolted securely in place to ensure the tramble and level would not change.

The stab and elevator assembly was checked and fitted to the saddle on the fuse. This is done with the wings on the plane so that tramble and level can be set relative to the wings.

The incidence of the stab is key to the Cap as the stab is nearly 5" above the centerline of the wings. I set the incidence with great care and after several adjustments, I got it within tolerance. I threaded pull string through the stab and through the wiring tube so that I can pull the elevator servo wires up to the center of the fuse without and problems. With everything straight, I glued on the stab and rechecked it for alignment.

 

September 18, 2008

 

 

Next was the rudder - I drew the cut lines and cut the parts on the band saw. The leading, trailing edges and the hinge posts were then all cut and glued to the foam rudder and fin. After it is dry, I will finish them and bevel and hinge in preparation for mounting on the fuse.

The tail wheel assembly arrived and it was mounted to the ply plate that was then bolted to the bottom of the fuse. This was done to provide access to the area under the stab. there are times when it is necessary to get in there and it is a shame to cut into the covering and the balsa sides.

The first cap was stripped of the electronics and the fly board was then mounted in the new fuse. The location will make it easy to deal with and to see the lights when pre-flighting the plane. The new fuel tank needed to have a way to mount it so that it can easily be revised to include a smoke tank. Since it is always a good idea to have the weight of the fuel over the CG, I made a mounting plate for the tank and fabricated it to allow for several tank arrangements in the future.

Below is a shot of the mounting plate in the fuse. It is in the plane with 4 screws and it allows for the addition of a smoke system without any problems.

September 16 and 17, 2008

 

Other projects took some of my time and so I have combined the two days into one session.

Wings - The wings were final sanded, beveled and hinged. Final Inspection was done and any rough spots were corrected. The wings were then covered and the ailerons covered to match the stripes. The control horn hard points and bolts were assembled and the wings now only need incidence pins, servos and final hinging to make them complete.

Stab - The stab is complicated in the way it is attached to the plane, the wood that is added to the elevators and the servos are in the stab. Made great progress on the building of the stab and elevators.

Above you see the stab with all the wood attached and rough sanded. Though it looks done, the work can now begin on setting it up for the servos and mounting on the plane.

First it is hinged and the taper in the thickness of the stab means the bevel for the hinges is not a line parallel to the trailing edge. As you can see above, the cut line for the bevel is deeper at the root than at the tip. This looks strange as you are doing it, but allows the elevators to pop up 45 degrees and the joint shown above is smooth and consistent.

Here is another look at the taper on the elevator side of the hinge. This is the secret to having the surface move a lot even though it is tapered only on one side. I like to taper both sides but it is not scale to the Cap.

Next I laid out the servo location on the bottom of the stab. I cut the foam with the hot tools shown below and checked for clearance with the servo mounts. See tips and tricks for more detail on this process. Notice that the servo mounts on the leading edge side are continuous in order to add strength to the stab in flight.

Below is the finished stab read to be glued to the fuse.

General - I did the first dry fit of the plane and corrected the small things that needed to be addressed. Completed a planning session with Brent on the location of the equipment and some of the expectations on the appearance of the plane.

September15, 2008

 

Stab progress -- rough shaped the balsa that was glued on and glued on more of the edges of the stab and elevator. It will take three glue applications to finish it

 

Fuse -- rough sanded the sides and bottom of the fuse. The next step will be to glue on the tail section and then the turtle deck. I am waiting for the engine to be delivered from DA and then the firewall and all of the front end can be done.

 

Wings --- Medium sanded the wings and ailerons and arrived at the final shape. Tapered the wing and aileron joint on both wings and hinged the surfaces. Added the hard points in the ailerons and applied the final fill before sanding to 320. Final sanding was completed and covering began with the bottom of the first wing panel.

September 14, 2008

 

The day began by adding the servo mounts for the rudder servo in the left rear section of the fuse.

The wiring and antenna tubes were installed at this time The sides of the fuse were then planked with ca glue on the sticks and white glue for the joints in the balsa planking. This process makes the sanding and covering of the fuse come out better than using ca glue on the joints. Once all the planking was in position, it was trimmed and sanded to rough shape. The top surface was checked to be sure it is flat to receive the turtle deck later.

Work on the wings ----- The hard points for the aileron servos were planked over and sanded and filled once the glue was dry. The joint between the wing and the fuse is key to the appearance of the plane and must be done with care.

I set the fuse on one side and positioned the wing tube on one wing so that gravity holds the wing to the fuse. The wing root cap is made from stiff 1/8" balsa and it was left oversized and put in position. I carefully inspect the joint to be sure the cap is fitting tightly to the fuse. At the trailing edge there was a taper that caused a gap between the wing and the fuse side. I made a block that filled the gap and was oversized to the top and bottom of the wing surface. Once this was all fitted, I disassembled the wing and added wax paper to the fuse and then glued up the cap and the block. I used tape to add pressure from the tip to the root of the wing.

The epoxy was allowed to dry and the other wing was processed the same way. The landing gear is aluminum and it was then positioned and drilled for 8-32 screws and blind nuts. The assembly was completed and the gear is ready for wheels and wheel pants.

Once the glue was dry on the wings, the root cap could be trimmed and rechecked for fit to the fuse. The wings were then rough sanded to bring them down to shape and a first fill put on any low spots or slight defects in the wood or the joints. After the ailerons are tapered and hinged in place, the medium sanding and a second fill will be done to prep for the covering process.

Next was the beginning of the stab fabrication. Cutting of the stab was done on the band saw and all the parts were laid out to keep them in good order. There were several balsa parts to be glued on to the cuts and the first glue job was completed.

September 12, 2008

I spent the full day on the cap and made some progress.

Wings -- The wings were fitted on the newly framed fuse and checked for tramble and for flatness to the top of the fuse. Adjustments were made to make them just right and then the ailerons were laid out and cut from the wing. The ailerons and the trailing edge of the wings were then lined with balsa so that they can be beveled and hinged later. After the glue dried, they were trimmed and rough shaped and the servo compartments were laid out and installed. There were hard points put in the servo bays that will be planked over in future sessions.

Fuse ---- The sides were completed and then set up over the plans in an inverted stance. After adjusting for quite some time, the fuse was glued in position with all the stringers, cross-stringers and the landing gear plate in alignment. Fast CA was used on the stringers and epoxy on the landing gear plate. All the Ca joints will be reinforced later with medium CA. The tail was then drawn into position and all of the aft structure was put in place. In order to hold position on the shape of the fuse before attempting the side panels, the bottom was glued into position cross-grain. This stiffened the rear of the fuse and will allow for the sides to be installed later without distorting the shape.

Stab ---- The stab is in two parts (left and right) and the panels were laid out and lines drawn where the cuts will be made. The elevators include a counterbalance that is cut completely off of the stab and then glued back on the elevators at a later time. The cuts are ready to be made and the stab will then be glued up.

September11, 2008

Today was dedicated to the wings and the construction of the fuse sides.

The wings were stripped of tape and the leading and trailing edges cut to rough shape. The incidence of the root and tip were checked and there was 1.5 degrees of washout in the left wing and 1 degree in the right wing. This difference is not enough to affect the performance of the finished plane.

The fuse of this plane is unlike the present Carden planes in that the motor box is contiguous with the fuse sides and there is a taper after the main compartment that continues to the tail. The fuse sides are constructed of the stick built frame and strengthening plates for the wing tube and the landing gear. The fuse exterior is comprised of many parts made of balsa and ply to give a main section that is strong enough to contain the motor and to prevent torsion of the tail section. All of these parts were put on the fuse and the firewall placement was set based on the 150mm distance from the spinner back to the mounting brackets of the DA 85. At the end of the day the fuse sides were complete in the main section and the next step will be to construct the motor box and the main equipment section,

Covering, parts, prop, and building supplies were ordered for delivery tomorrow.

September10, 2008

The Project begins with the wings. While the wings were skinned as I received the plane, you can see the skinning process by looking at the build article for the Carden Edge in the section marked "Build Articles".

The wings first got the leading and trailing edge balsa glued on and taped to hold them in position. I do this before cutting the ailerons so that the trailing edge will be consistent on the wing and on the ailerons. This is allowed to dry and then finished to shape with gouges and a plane. This balsa gives protection to the trailing edge and allows a more consistent sizing of the trailing edge thickness from root to tip.

Next I began the fuse by laying the plans out on the work area and framing the 1/4" stock over the drawing. This takes time and must include two builds (one left side and one right side). When they were both done, the size is checked and adjusted as needed to make them the same. This precision is necessary later as we get the fuse in three dimensions.