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Preparing the skins for the surfaces and fuselage parts

This process is simplified by the outstanding prep done by Dennis.  The 4” wide 1/16” balsa is edge glued to form sheets large enough to cover the foam parts. Dennis processes the edges of all the sheets so that they glue up without additional trimming.

I then weighed all the sheets of planking and arranged them by weight.  The stronger (heavier) cuts will be on the surfaces while the more bendable sheets will go to the turtle deck and the other parts that will require the wood to bend around the shape of the foam and not split or crack. This is key to lateral balance of the finished plane.

Beginning with the wing panels, I tape the sheets together per the plan. The panels are made slightly over size so that there will be trim after the skin is put on the foam core.

I set up a piece of MDF on the pool table and ensure it is clean and flat.  This will be the place to put the panels after they have been glued so that I can weigh them down and ensure they will be end-to-end and make a flat panel.

Two of the four wing panels are shown here and they are ready for the gluing process.  They are taped on one side to ensure the surfaces match up.

The panels are then turned over and the panel flexed so that the edges can be glued with any good white glue.  The panel is then straightened out and the excess glue is removed.  I then sanded the joint to get a little sawdust into the glue joint.  This will serve to make the joint invisible in the final form and will make the glue joint more sandable.

The panel was then moved to the MDF board and I place glass over the panels and added weight to be sure the panel is flat to the MDF.  After drying completely, the next panel is glued up and placed flat to dry.  This process is repeated for the 4 wing panels, 2 vertical stab panels, 4 horizontal stab panels and 4 panels for the fuse.  At the end of this process, all the skins are cleaned, tape removed and sanded to be flat and ready for gluing to the foam cores.

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Construction of the wings

The sanding is done to finish the surface before they are glued to the foam.

Next, the tube is fitted into the wings and glued in with Epoxy.  The strength of the process is that the tube is supported by ply at both ends of the tube.  The root of the wing will get a ply covering that will support one end and the other is shown to the right.  There is a slot cut in the wing and the ply former is fitted over the tube.

The servo locations are drawn on the foam and the servo pockets are cut with a hot wire and some fixtures that I made for the job.  The fixtures are used to guide the cutting of the pocket for the servo and the holes for the hard wood mounts.   The mounts are then set with epoxy and are located flush with the foam and the wing sheeting is then glued to the mounts.  I have found this to be a strong system and yet very simple to do. The cutting of the pockets and the gluing takes only moments and is very secure. For more on this technique, see the tips and tricks section.

The wing is then sanded and checked to be sure it is ready.

The sanded sheeting is then cleaned and the wing is ready to be glued up.  On the far right side of the photo to the right, you will see a small bit of hardwood that was glued in and sanded flush.  There is a second block on the wingtip side and these are used to locate the sheeting on the foam. Another view of the block is seen 3 photos earlier.   With the glue on the sheet and about 300 lbs on the foams, the sheeting will move and change alignment if it is not held in position.  As I get the sheet aligned on the foam, I use some slow CA to glue the sheeting to the blocks.  This will prevent the movement of the skin.  Once the glue-up is done, the wing is put back in the foam cradle and placed on the flat table.  An additional flat sheet is placed on top and blocks are used to compress the foams and clamp the sheeting in place.  This will dry in 6 hours and the other wing is then glued up. 

The wings are then stripped of all the weight and shucks and checked for straightness and quality of the wood bond to the foam. The leading and trailing edges are cut back to the foam as are the root and wing tips.

The leading and trailing edge stock is cut from 3/8 x 4” balsa and the cut strips are then glued on the wings.  This is done with white wood glue as it sands better and holds just fine.  After drying, the tip material is added and the entire wing shaped to remove excess material.  The foil will be brought to the final shape later as this protects the final surface from damage.  I do not do the final shape until just before covering begins.

The wings are fitted  to the fuse for the first time and the level and tramble are checked and adjusted. The tramble is checked with a string from the center rear of the fuse to each tip.  This is adjusted to make the length the same.

 The root cap is then fitted to the fuse and glued on to the wing.  This is done by setting the fuse on the side and placing one wing on the wing tube.  Having the wing vertical is letting gravity help fit it to the fuse.  If there is a gap between the root cap and the foam wing end, I fill the gap with balsa and glue it up when fitted.   

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Building the Fuselage

 

There are many tracks one can take to build the fuse and I begin with the sides.  They are the most critical element to the correct alignment of the final product.   I used straight angle clamped to the board over the side view plans.  The sides are made from 3/8 square balsa and the first longitudinal member is pinned to the board against the angle to be sure it is straight.  The vertical members are precut and are exactly the same length.  These are glued to the bottom longitudinal and then the top longitudinal is glued to them.  The cross braces are then added and the side is complete.  A second side is made and compared to the first side to be sure they are identical.  The only variation from the plans has to do with the anti-rotation blocks that are supported by the vertical members.  The members were moved to a position that would support the blocks better.

  The Carden plan is to bolt through the blocks into the wing root to secure the wing to the fuse.  Since I find this concept tedious when assembling the plane, I use a stud in the wing root that protrudes through the anti-rotation block when the wing is assembled to the fuse.  I then run a nut onto the stud from within the fuse and the assembly of the plane is complete.  These blocks will be used to ensure the wing stays at zero incidence and therefore they are not put in the fuse sides at this time.

The next step is to add the 1/8” balsa to the sides taking great care to make one left and one right side.  I have made two left sides in the past and I find it difficult to assemble the fuse.  The sides are edge glued and end glued as the 1/8 sheets are too narrow and too short to make the sides in one sheet.  After the glue-up is dry, I sanded the sides and glued them to the side frames.  The assemblies are then edge sanded and checked to be sure they are identical in size and shape.

Once the sides are planked with the 1/8”, I added the stab tube support and the wing tube supports that are made of ply and will act to align and strengthen the tubes.  These are key steps because the tubes must be straight and great care must be taken to be sure these supports are set up straight.  I put the two sides over each other and then put in the tubes and ensure the tubes are square to the board.

 

The motor box is another key part of the fuse and it must be strong and assembled straight and square.  This is made from ply wood and therefore I use epoxy to glue the parts.  I find I can simplify the later steps if I take some time with the motor box.  The joints are butt joints and I do not care for those in a strength area, so I begin with triangle stock at all the butt joints.  I put the triangle stock on in the flat and they help guide the glue-up of the motor box.   There are some hardwood mounts for the landing gear plate and for the firewall. You can see these being installed. I also put on formers that will attach the box to the side rails later.  These are easy to glue on and get square while the sides are flat.  You can see the items glued in place.  I also like having a floor in the equipment compartment if there are canisters.  I glued in more triangle stock to support the floor after the box is constructed.  These steps all make for a stronger plane.  In order to make back the weight I added with the reinforcements, I use lightning holes in the sides and in the other parts of the unit.  We have gained strength without gaining weight.

After all the prep, it is time to assemble the motor box.  This is a process of using 30 min epoxy and taking 20 minutes to align all the parts and get everything square and lined up correctly.

The two views of the motor box shows how the assembly is aligned using clamps and speed squares to be sure everything is fitting together.  There was a dry fit that allowed for adjustments to the parts to get everything right before the glue came into the picture.  This construction takes more time than just gluing it up, but it pays for itself in a straight and clean flying plane that will hold up for a long time.

The hardwood in the first former is assembled with epoxy and I add 12 sheet metal screws in the sides and front to ensure things stay where we put them.

Now it is time to begin the framing of the fuse.  I dry fit all the parts over the top view of the plans.  With clamps and squares I can be sure all parts fit as I want them.  Fine adjustments are made to get ready to glue.

Begin by making the 3/8 square horizontal braces that fit in the top and bottom of the fuse.  I cut them at the same time to be sure they are precise and have the angle to match the sides.  Pin the bottom one over the plans and be sure of the alignment.

I then assemble the sides over the plan and use blocks on the outside to hold the sides in perfect alignment.  Next, use speed squares to align the sides square to the board.  I start at the back and secure everything moving to the front.  No glue is used for quite a while yet.   This takes time and some fitting to make everything work.

This is a second view of the fuse looking aft.  The braces laying on the plans are for the upper side and have not been secured in place as yet.  They are pinned in place for alignment and glued later.

Alignment of the motor box is key.  I position the parts with braces and fit it until the marks on the plans fit to the box.

The front of the motor box is aligned with the plans and it is ready to be glued in place. 

The wing tube is now put in position and checked for tramble and level.  It will not be glued in as one final check will be made with the wings before its final position can be established.

I use thin CA on the balsa joints and then reinforce with gorilla glue.  The ply joints are secured with epoxy and reinforced as needed.  This process takes time to get done as all the braces are now glued in place.  Once it is done, the fuse is turned over and the braces are added.

The fuse is now framed and I go about checking all the joints and sanding for shape and alignment.  The fuse in then placed on a flat surface in the upright position to receive the wings.

As noted in the wing section, the wings are set on the fuse and adjusted for level and for tramble.  The wing root cam is then set to give a clean joint with the fuse.  It is time to set the incidence of the wings and to make the system that will hold the wings on in flight.  I begin with 5/8 hard dowels for the wing root and they are center drilled to receive a dowel in the leading edge position and a ¼ x 20 bold in the aft position.

The center drilling is no problem on a drill press with a vice.  Once this is done, the holes are laid out on the fuse to be sure they will hit the reinforcements that are in the fuse structure.

I use a flat bit the size of the dowels and I grind the bit to get a tight fit in the wing root

The root is now drilled parallel to the wing tube and deep enough to take the entire 2 ½" dowel.

The dowel is glued in place being sure to get sufficient glue in the hole to support the pin.  Failure of this joint gives dire circumstances in flight.  Let this dry and then the fuse is next.

The wing is fitted up to the fuse and checked for tight fit.  The pins are now set in the dowels so that they protrude only about one inch from the root cap and we are ready to set up the incidence.

As you see above, I use a digital level that can be bought on Ebay for a reasonable price as you do not need the 6’ long ones for construction. 

The upper rail is the datum line and the wing is set at that same angle.  Once the level is read for the upper rail, the wing is rotated around the tube to read the same number and by pushing the wing into the fuse, marks are made by the pins telling where to drill.

After drilling the pin holes, the angle is checked to confirm it is correct.  I like to get within .1 degrees of the correct reading.  If you miss the right reading and have to oblong the holes to get it right, then cut a ring for the inside of  the fuse.  Drill a hole in the ring the size of the pin and glue it to the inside of the block to hold the pins in position.  Use ply for the ring and the strength will be just fine.  The ¼ x 20 bolt in the aft position is also used to hold the root tight to the fuse in flight.

Incidence is set and the same process is used for the stab and elevator assembly.  They are first set level to the wings and tramble is set so that the wings are heading in the same direction as the stabs.  The incidence is set to be the same as the wings and I do that with two bars and one digital level.  A small block is glued to the fuse side to position the stab and this will due until I am ready to actually mount the stabs.

The bracket is then mounted to the stab and the fuse using blind nuts and socket head bolts.  The balsa block on the top of the stab is the index to be sure the angle is correct.  The block is then removed.

The plane is now in flying condition with the horizontal surfaces in position and it is time to get the rudder and fin in position.

This is combined with the need to produce the elevators and begins with the layout of the rudder/fin combination according to the plans.

The stabilizers are drawn also and attention should be paid to the plans as the cut lines depend on the thickness of the wood to be glued to the cut lines.

Above you see the three surfaces after cutting on the band saw.  The lines are drawn and confirmed and then the surfaces are taped to the foam shucks and then cut on the band saw.  I keep the shucks as there are other steps that will require their use.  After the cutting is done, I glued up all the cut surfaces with the wood shown on the plans.  After drying ( white glue needs 2 hrs to set up) I trimmed all the wood and brought the surfaces into rough shape.

The elevators are hinged and beveled and prepared for the hard points.  I will illustrate the method I use for hard points later and it is used for all the surfaces except the rudder.

Next, plank the top of the rudder fin saddle in preparation for the mounting of the fin.  There is a potential problem getting into the fuse if the elevator wire should be lost inside the rear portion.  I counteract this by putting on the bottom of the fuse and then building a hatch that will allow access to the wiring area.   

Blocks are glued to the fuse side to contain the foam and wood bottom portion.  The hatch will fit in the same area as the tail wheel mounting plate, so I recess the plate into the bottom frame to allow the hatch to fit tightly over the entire area.  This plate is epoxied in place as it will have to carry the load of the tail wheel.    Next the bottom is glued in place and allowed to dry.

The end of the bottom panel is then fitted with 2 thickness of 1/8” ply with the pegs in place. The frame of the hatch is built right on the bottom rails of the fuse. Small areas of ca hold the hatch to the frame and are later cut back off.  This is the best way to form the hatch to the shape of the fuse and have everything fit.

After the shaping is done, the hatch is removed and the view at the right shows the bottom without the hatch.

The hatch is secured with a 5/8” dowel that is center drilled and a 6-32 blind nut is used on the under side of the plate.

This gives a clean installation of the hatch and it is nearly invisible.

The pull- pull rudder assembly now needs to go in and that will include the placement of the holes in the fuse side for the wires to pass through.  I like to line the holes with blue nyrod so that the holes do not change shape over time.  The rudder tray is in the fuse and I lay out the tray on the plans and then plot the exit point for the wires.  This is then drilled and the nyrod put in and trimmed to the fuse sides.  After covering and final assembly, the wires are run to the rudder hooked up.

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Skinning the other fuselage parts

The other parts are now skinned in much the same way as the wings.  The turtle deck, hatch and bottom are the obvious parts and there are others that must be glued up before the fuse can be fully assembled.  The skins are sanded and the foam is sanded before assembly.  I use Gorilla glue and I spray some water on the foam to be sure the glue is activated.  After gluing the sheet, it is placed in the form and by taping and adding weight, the form is compressed to the correct shape.

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Complete the stab and fin

The stab and elevators come in foam and also need servo bays installed before the skinning can happen.  The servo bays are laid out relative to the hinge line and that is shown on the plans.

The hot cutters are used to cut the servo bay and the mounts out of the foam.  This is fast and accurate and well worth the time the templates took to make.

The stabs are shown on the left and the mounts are in and sanded flush with the top surface. It is key to have the mounts in contact with the skin and with the root cap that will be put in later.

This setup is recorded on the plans so that we can find the servo bays later.  The skin is now applied and allowed to dry.

Once the skin is on, the incidence plate is put on and the tube liner is glued in place.  The root cam is now glued on understanding that it will not cover the entire root as the elevators will be cut off of the stab and further work done on them.  I like to leave the stab and elevator in one part to set the incidence the same as the wing.  The wider root gives more accuracy to my method of setting up the stab on the fuse.

The stab and ruder are cut after the incidence setting described elsewhere.  After lining the cut edges with wood, the bevels are put in place and the hinging is completed.  This brings the stab, elevator, vertical fin, and rudder into shape and rough sanding is now completed.

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Assembly of the top of the fuselage

Now that the bottom is on the fuse and the lower hatch is in place, the fuse will stand on its feet to avoid damage to the soft under-side.  I stand it up and begin to fit the turtle deck on the top.  It is glued into position with white glue and great care is taken to match the sides with the fuse sides.  This is then let to dry and  sanded to shape.  Notice the continuous use of tape as clamps.  I find this works best with the contest grade wood we are working with as it leaves no dents to fill later.

Next I put on the fin.  It is positioned very carefully and then glued in place.  It will dry and then it is time to add some strength to the fin.  Remember that in a knife edge the rudder will be carrying a lot of weight and it would be good to have it stay right where we put it.

At some point in the build I realize that it suddenly looks like a plane!  This is the point for me and it gives a clear idea of the look the plane will have later.  All of this must now set up for about one hour before we can proceed.  I hope you have a second plane being built so you can stay busy.  Mine is the repair of a ¼ scale cub that had a battery cell failure and visited with the lake in an unsightly way.

To finish the rudder fin we just have to make and fit the faring and add a support rod up into the  fin from the bottom.  First the faring is carefully fit in the opening between the fin and the end of the turtle deck.  This is done by laying out the shape of the cut on the bottom of the foam and wood block and cutting it on the band saw.  The adjustments are made with a coping saw and many adjustments are made to get it right.  When done, it is glued in place with white glue and then sanded to the final shape.  The hatch in the rear is used to add the rod into the fin.

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Final install of the motor system

Now I like to get the motor in place with the canisters.  They were fitted in earlier and the construction is now ready to put them in for good.  The top of the canister compartment is first epoxied in place and then the entire compartment is coated with thin epoxy to help it take the heat from the canisters.

 The canister rack is completed and put in place to hold the back of the canisters in place and it is lined with silicone tubing to make it safe to contact the canisters. As you see on the right, there are holes in the rack to allow air to pass by the canisters and out the bottom of the fuse.   The hole is now cross planked with balsa and a hole cut for the exhaust.  It is rough shaped and the bottom of the fuse is complete and ready for final shape and sanding just before covering.

The motor is now put in place with ¼ - 20 bolts and stop nuts with washers to spread the load. The canisters are attached to the motor and installed in the rack in the rear. The motor system is in place and now we can shape the front formers and begin the cowl installation.

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Fit the cowel to the fuselage

First I trim the cowl to allow for the pipes on the canisters.  This is a cut that will be reinforced later once the structure is in place inside the lower cowl

The lower support parts are set up with the bracket to attach the lower cowl to the motor box.  I use a block of pine to align the driver to the head of the fastener.  This will allow the removal of the lower cowl without any problem.

The cowl is fitted up to the fuse and the supports trimmed to fit the fuse sides.  Once this is done, the supports are glued in place and the lower is ready.  This step will take a lot of time, but it determines the position of the front of the plane and the upper hatch so it must be correct.

It is key that the gap between the fuse and the cowl be even and spaced at 1/16”.  This will give a  smooth appearance and will not allow the two parts to be in contact and become damaged with vibration.

The 1/16 alignment shims are shown here.  The clamp is to be sure the support is glued to the inside of the cowl at the top of the support.

This is a second shot of the clamp in position and the glue dry.  The gorilla glue foams and that helps form a fillet with the support

The lower cowl is now in place and the upper is placed in position and taped to hold it .  I have reinforced the inside of the cowl with 1/8 ply strips to hold the blind nuts.  The holes are marked and drilled through both thicknesses of the material.  I use the clearance bit for the 6- 32 screws.   I then add the blind nuts after drilling the inside cowl out.  The blind nuts are pressed in and then reinforced with medium CA. 

The upper cowl is now in position and the upper ply support can now be set in position to support the back of the upper cowl.

This is a shot of the lower cowl with the blind nuts and the upper cowl support in place. 

With this step done, we now put gorilla glue on the upper support and reinstall the upper to its final position.

As you can see, the upper is taped to hold it in position with the spinner back plate.  The cowl can sag the nose down and that will open the gap of the cowl to fuse joint and make the spinner out of alignment.  The gorilla glue gives working time to get the position just right.  Once this dries, I remove the upper and reinforce glue the support to the cowl inner.  The cowl is now in place and secure.

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Set the canopy hatch

Now that the front end is secure, I take the last step of the build and begin to set up the canopy hatch.  Carden shows the top hatch in two parts but I find it easier to build it all as one.  This will give access to the equipment and allow better checks to be made on the equipment.  The construction also allows the all important upper cowl to hatch joint to be made just right.  I first set the balsa rear hatch cover in place as shown.

I begin by cutting 4  dowels ½” long and center drilling for the 6-32 bolts and countersinking for the heads of the bolt.

These hardwood dowels are then set in  the fuse sides where the hatch hold downs will be positioned.  These are glued in with white glue and allowed to dry.

Rails are placed on the fuse sides  flush with the inside fuse surface.   The hatch is built on this frame and it must be down flat to the fuse top.

The rails are then attached to the ears with dowels as shown in the lower left corner of the photo.

The foam top is then cut on the band saw to fit inside the rails and it is glued in place.  The sides will be built up with balsa and then carved in line with the fuse side.  This will ensure a perfect fit to the fuse and the attachments will hold it tight.

The rear of the foam top is secured by the cross member shown to the right and it is secured with a dowel.  This surface will later be the dash panel.  This assembly is allowed to dry and then additional strips are glued to the sides to build the sides out beyond the finished line of the fuse side.  When construction is done, the assembly is sanded to shape to match the fuse and the cowl.  The cockpit will be addressed later

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Add the covering

The fuse is now sanded and filled to satisfaction for covering.  I sand the last time with 320 grit and then cover immediately.  The covering process takes time and practice to perfect your techniques.  I will not spend any time here showing the covering process.  All covering is now applied and the hinges are set in place.

Once all the covering is in place, the insignias can be put on and the  surfaces glued on with epoxy on the robart hinges.  It is key to make the hinges work well and the actual hinges are treated with Vaseline before they are glued in place.  As the hinges are put in, the surface is checked to be sure full throw can be made.

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Set the equipment

Next the servos and linkages are installed.   I make all my own links in order to be sure they are of the best quality.  The plane will not perform well if the links fail in flight.  I use 4-40 allthread and I overlay the center of the rod with c/f tubes and ca them in place.  This gives the best results I have found and the appearance is very nice.  See tips and tricks for more detail on the links.

The pull-pull system is now completed and the rudder is tested and centered on the SWB rudder tray by using the supplied wrench to adjust the length of the wires.  The stab servos are mounted and wired up to the equipment area. All servo wires are hard wired to the power board except the elevator servos as there are take-off stabs.  These plugs are secured with plug clips.  Since plugs cause current losses and they can come unplugged, I avoid them whenever I can. 

The plane is now looking close to completion and that is an illusion as there is a great deal left to do.  The final steps are often overlooked in the rush to get it in the air.  We have all heard the horrible stories and I am determined that such things will never happen to my planes.  Because of that, I will describe the final steps in some detail to make clear that they must be done with great care.

The fuel system is next to get our attention, and the hardware is assembled  and then pull-ties are added to all the tubing joints.  The fuel dot is put in place ahead of the wing on the right side of the fuse.  With all the connections made, the tank is put in place.  Notice that the vent line is looped behind the tank as this will allow the plane to get in a nose down configuration in the shop and not spurt gas on our clean shop floor ----  your shop is clean by now -----  right?? The vent line is routed out the bottom of the fuse and an in-line filter is placed on the exit of the tube.   I air test the tank to be sure there is no leak to bother us on the first flight. 

The cowl is now mounted and striped off with tape and painted yellow  and then the white is applied.  The turquoise top is painted last and the color can only be done in custom mixed paint as I have not found any paint that matches some coverings.   

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Wheel pants

At the same time, I set up the wheel pants and they get the yellow paint to go with the bottom of the fuse.

The aluminum gear has been changed to c/f and he pants are secured to the gear with two 6/24 bolts into a ply plate installed inside the pants and equipped with a blind nut.

In addition, there is a ply plate on the interior outboard wall that the shaft fits into to secure the pant from bending in flight and some have even fluttered causing strange things to happen.  This setup seems to work for me though it takes some time to get all the parts epoxied in place and set up.

The pants are now on and the landing gear is mounted for the final time.  All fasteners are thread locked during final assembly and that is checked in the last checkup to ensure they will stay in position.

The plane is now looking more complete and it is time to move inside and begin the equipment install.

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Final install of equipment

The rudder tray and the pull-pull system are in place as described earlier.

The throttle servo is mounted in a structure that will allow it to be mounted in the motor box and aligned with the engine throttle arm.  I drill a hole in the firewall and make the linkage from 4-40 allthread.  I put it all together and hook up the linkage and electronics.  After the servo is centered, I reduce the throttle on the transmitter and glue in the servo assembly.  This makes all the alignment of the linkage automatic and the transmitter is now set up for full throttle travel and some expo is used to make the throttle performance linear on the stick.

Next the ignition module is mounted in foam such that the wires route properly through the motor box top.  Once the module is mounted, I finalize the wiring and leave the battery loose as it will be used to set the center of gravity.  The motor box top can be put in place after all the ignition wiring is complete.  I have used an opti-switch so that the ignition can be activated from the transmitter.  This system requires an additional slide switch to prevent battery drain.  The switch and indicator light is installed on the left side of the fuse behind the cowl.

Above you can see the choke is attached to a linkage and run through a grommet in the bottom of the cowl.  This is handy and will allow for the operation of the choke

There always seems to be a need to get into the cockpit area after it is sealed up with the canopy.  I built a trap door in the center section of the floor so that the pilot figure and the floor can be removed when needed.  The floor of the area is painted with spackle paint and allowed to dry.

Next the dash board is constructed with a visor attached and the assembly is painted yellow before having the gauges installed in the panel.  Other decorations are added and the pilot is sized and glued in place on the trap door.

The shots above show the completed cockpit with the dash panel and the yellow structural tubing simulations.  With the trap door out of the plane, the upper hatch is secured in position with the four bolts and I confirmed that the position was correct.  I then added a brace to be sure the rear former was tight against the turtle deck before the canopy is glued in place.

The canopy was then trimmed and positioned on the cockpit.  I use the formula 560 canopy glue for this  application as I have found it to be the best at holding and it will dry clear if you give it a few days.  This is not a simple thing to align the canopy and get it just right   The canopy glue will give you about 15 minutes to get it right.  Be sure to wipe all the glue off of the covering before it sets up as it will bind to the covering and recovering will be your only option.  I use tape to hold it overnight and if it is pulled down tight to the surface, it will be a nice fit.

The raw edges of the aft wall will not show as I use ¼” striping over the joint all around the canopy.  This is scale to the plane and it will go a long ways to holding the canopy in position for a long time.  The hatch cover is constructed well and there is no flex in the structure, so the canopy should stay in position for a long time.    After the glue is dry, carefully work all the tape off and add the black striping tape.  The brace was then removed and the pilot can be put in final position with locktite on the screws that hold the trap door.

   The Rudder tray and all the servos are in and the links are in place.  I next put in the power distribution board and the wiring for the switches.  The equipment came from 42 percent products and is very high quality stuff.  The high powered lith ion batteries have very little weight and they are fully redundant.  The switches are more like circuit breakers and will positively not fail in flight as they clip together in a way that just can not fail.  The difficulty is (always a price for eliminating one problem) we will have to unplug the battery from the switch harness to charge it.  This is a small price to pay since the batteries will fly all day and you will not need to be inside the plane at all.

With all the equipment in place and everything bolted in for the first time, I set the plane in the balancer to see where the CG came out.  This was the surprise of the day as the plane was very tail heavy and you do not want to have that for the first flight!!

I examined the plane and was perplexed since I have had the pleasure of many Carden builds and never had this happen.  Once I tried to balance a plane without the muffler and it was tail heavy too.  After checking the plane the awful truth set in that the plane was tail heavy.  While I thought it over, I set about moving everything ahead.  The two feather light batteries were moved to the firewall and the ignition battery went up there too.  All other movement was done and the plane still showed tail heavy. 

The problem came from several areas:

1. The new DA 100 is lighter than the old one and that seems like a good thing since the motor now weighs in the area of 6 oz less than before.
2. The battery system is a whopping 9 oz lighter than a nicad of the same power and that means I can not change the CG with the batteries.
3. While I build light, there are 2 servos in the tail and I did add a trap door in the lower tail area that will add slightly to the tail weight.

I fixed the problem by replacing the motor bolts with larger ones and adding an extra set of fender washers behind the lock nuts. 

Lateral balance is checked and no adjustment was needed.   In the trimming process there is a further check of the lateral balance.

As the equipment settled in, you can see below that the rudder tray is  in the aft area with the switches located for convenience.  The board is centrally located and the aileron wires are plugged directly into the board.  The use of extensions is discouraged as it will involve power losses and a source of failure.  The tank would not go over the CG because of the canister compartment so it is located ahead of the wing tube.  This is the finished installation and all the surfaces are checked and aligned.

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First flight setup of the radio

Everyone has their way of surviving the first flight and mine is to set the triple rate switch to have small, medium and large throws so that I can select all three on the first flight.  I convert to my normal throws after the first flight. 

During the flight I am trying to complete some things

1. survive
2. check the CG to make adjustments if they are needed.  This is done by flying flat into the wind at ¾ throttle and rolling to inverted.  It should take just a touch of down to fly flat and if it takes more or less, then we know how to adjust.
3. Check the plane for nasty habits on stalls.  Fly one mistake high and slow the plane and apply up till it stalls.  You want a little stall and the plane stays straight.  If not, adjustments will need to be made.
4. Check for power --  just fly straight up and see how it flies.  This motor will be breaking in, but it should still have unlimited vertical.

While you are up there, check incidence by putting it in a vertical down line  with throttle low and see what it will do.  If it pulls out or tucks under, then the incidence is suspect.  ( this one also depends on the CG being correct.