Building the Schuler 1:3 ASH 26

by Rick Briggs

CANOPY LATCH

If your going to spend a lot of time building a good looking scale ship, why have a canopy latch on the top of your fuselage that’s not scale. Her is a simple way to latch your canopy and maintain a scale look.

The parts are real simple, 1- 1/4″ T nut, a 2 1/2″ piece of 1/4″ square brass tubing, a standard canopy latch from Hobby Lobby, and a length of Sullivan throttle cable, the smallest diameter.

Cut a 3/4″ piece of square brass tubing, drill a hole for the latch, soldered a small brass washer to the latch near the bend, slide the tubing on the latch and solder another brass washer on the end of the latch, being careful not to solder the tubing to the latch, you want it to swivel.

 

Epoxy the 1/4″ T nut to the back edge of the gear door. The 1/4″ square tubing is mounted to the T nut with a 1/4 allen head screw, tighten just enough to let the lever rotate. I soldered an eyelet to one end of the tubing as well.

Use a piece of 1/8″ plywood to mount the cable tube, approximately 4″ to the rear and in line with the end of the tubing. Don’t glue the cable tube till you mount the canopy latch to the top of fuselage.

Epoxy the latch to the top of your fuselage, be careful not to glue the moving parts!. I use 3 layers of 3/4 oz fiber glass cloth. Next epoxy a piece of 1/8″ plywood 2 1/2″ in back of the square tubing.

Now slide the cable tubing through the 1/8″ plywood mounts. the cable should make a smooth arc from top to bottom of the fuselage, you want the cable to slide smoothly in the tubing with no binding.

C. A. the tube at the top first, make sure the latch is able to have full throw to the rear.

Next, cut the outer tubing to fit at the bottom plywood mount. C.A. the tubing to the plywood. Now slide the cable through the eyelet on the end of the tubing as in the photo above.

Take a 1/8″ long piece of 1/32 brass tubing, slide it on the cable. With the brass lever parallel to the back of the gear doors, position the 1/32 tubing next to the lever, solder the tubing to the cable, DON’T solder it to the lever! you want the cable to slide through the eyelet.

To operate the latch, you open the gear door and push the lever to the rear and, voila its magic!

INSTALLING THE SIDE COMBINGS

Before we start, I want to let you know that this is the first time I have gone to this much detail for a scale ship. I did use a lot of photos of the full size ASH 26. By no means is this an exact replica of the full size ship. I just wanted to get as close as possible without going completely mental. This hobby should be fun, at least for me! If you are a little intimated here, don’t be! working with a good quality car body filler is real easy, Just use a good brand of filler. I will try to show you my tricks of the trade, as it were.

Here you can see I made some temporary formers to help shape the combings. I used 1/4″ balsa wood with masking tape applied to the outer top surfaces. Why masking tape? Bondo or car body fillers won’t stick to masking tape! The formers were spot glued with C. A. Take a little time to place them even and at the same level with each other.

Use more masking tape to protect the outer surfaces to the fuse, if its already painted as this one is.  The blue block is to shape the spoiler and flap control recessed area.

Here you can see the combings with the formers removed and roughly shaped. Remember the little blue block? now you see what it did.

When you start filling the area with your filler, do it in layers of 3/8″ or so, don’t fill it all at once, car filler will get hot if you try to fill to thick of an area, heat is not good for glass fuselages it will warp and deform your nicely painted ship. I have a cold bucket of water with a rag ready just incase it gets to hot.

I use 80 grit sand paper to do all the basic shaping. As you get closer to what you want in the shapes, start using finer sand papers, I usually finish up with 220 grit. Also I use the 3M wet or dry papers, DRY, they last longer.

Here you can see the air vent, and the mounting plate for the hand crank for the seat adjustment. I used a piece of carbon tube I had laying around, the mounting plate is a piece of 1/16 aluminum plate cut and shaped, then bonded and faired into the surface.

Here is a good example of how you can work with the filler, if it doesn’t look good just add a little more and sand it till you get it the way you want it. And the best thing, it goes fast because you are working with a material that dries quickly so you can get fast results.

Here the spoiler and flap recess is taking shape, along with the faring for the tow release. Also notice the notch at the top edge of the combing. At this point I am using 220 grit sand paper. Once you get close to the shapes you are making, Spray a light cote of light gray lacquer primer to see the shapes more clearly, then sand to final shape.

These are the spoiler and flap controls. I have made the control rods of brass tubing in combination with an EMS hand grip. The ends of the rods are in brass sleeves, later you will see how the finished controls will be installed. The sleeves are notched into the side of the combings using a dremell tool. I tack them in place with CA, remove the rods, and then I fill with body filler, and sand to final shape. Use masking tape over the ends of the sleeves wile you are filling, so you don’t get filler into them.

Here are the finished, flap, air brake, wheel brake and tow release handles. Using brass tubing and EMS handles from their cockpit kit. The tow release was made form a birch dowel, turned and shaped on my drill press.

NEW SEAT TRAY AND REMOVABLE SEAT

I wanted to be able to fit a full 1:3 size “Alex” pilot into the seat. So I proceed to make a seat pan and seat that would be a little more to scale and accomplish my goal. I have to assume that for this article you have some fiberglass and mold making experience, If not, got for it any way.

Using the stock seat pan I cut out the area where ones legs and buns would normally be. Then using modeling clay and balsa wood, I roughed out the shapes of the seat. The black and red cardboard is the recess for the shock absorber.

What I am after is a seat that fits directly to the bottom of the fuselage as in a full size ship. After getting the desired shape, I then mask of the areas to protect them from the glass lay up.

Next I sprayed “Partal” mold release on the area of the seat so the fiberglass seat will lift out when cured. Using West Systems epoxy and 6 oz. glass cloth, I built up 4 layers on the seat area.

After the part cured, I then detail the seat with bondo and primer so I could then make a mold to produce the final seat part.

Here are the rough parts being detailed in preparation for making the molds. The white part is the original seat pan from the kit. The second seat pan was modified at the sides so the seat fits correctly as in the full size ship.

Now you can see the molds and the new seat pan and seat. Also in the photo is the head rest that bonds to the top of the seat.

Below the parts are assembled to show you how the seat fits. To mount the seat I just made a slot in the back of the seat pan, it’s just above the slot for the shock absorber, and on the back of the seat you bond a piece of aluminum that is 1″ wide and is bent in a Z shape so you slide the seat in from the bottom and it hooks into the slot, then a single screw holds the front of the seat in place. This way you can mount the pilot to the seat and with one screw, remove both seat and pilot for access to your R/C gear.

The head rest is hollow on the face so I could fit a hard foam piece that is covered in cloth, and inserted into the face so I leaves a clean edge when done.

RETRACT AND R/C EQUIPMENT INSTALL

This is a HOCK retract.  It has a shock absorber and brake.  The unit comes with brackets that mount to the frame for retract and brake servos.  You also can select different diameter and types of wheels.

When I ordered my 26 from Reinhard, I had him install the retract, so the bulkheads came installed with the retract.

As you can see the retract assembly fits quite nicely. Two allen head bolts hold the unit in place. The bottom of the shock mounts to the two aluminum struts with a small bolt.

Here the R/C gear is in place. I try to keep things tidy by using mini ties with a self stick anchor pad that’s 1/2″ square, you can get them at your local electronics store.

Also you can see were I cut down and widened the notch in top edge of the main retract bulkhead so the seat fits properly, look at the photo above.

This shot shows the location of the battery packs. They fit forward and under each side of the flat portion of the seat pan. The square portion of the seat pan makes for a great location to fit removable ballast weights. I used some flat 3 oz. fishing weights. There held in place with a 1/4″ nylon bolt that fits through holes drilled in the weights with a “T” nut on the bottom weight. Simple a fast to adjust your ballast.

Here the tow release servo, switches and battery backup unit are installed. The tow release is connected to the servo with a simple throttle cable, the servo arm is in the up position and it lines up inside the square portion of the seat pan.

The batteries are held in with Velcro that’s mounted to flat pieces of plywood epoxyed to the bottom of the fuselage. I used two 5 cell 2000 mh with a voltage regulator set a 5.2 volts.

COCKPIT TRAY SEAT AND COMBINGS IN PLACE

Here the seat tray and seat are in place.

Here you can see the canopy frame is in place so you can see how the combings fit. The cloth on the sides were first mounted to 1/32 poster board cut to fit the sides. I use 3M 77 spray to bond the cloth to the poster board. Then I glue the poster board to the fuselage with Zap a-dap-a Goo II.

Also you can see the air vent and the seat adjusting handle. The face of the vent was made from a piece of birch dowel, turned on my Unimat lathe to fit the inside of the tube, then painted with gloss enamel. The handle is a piece of flat aluminum, plate, with a round knob made again of birch dowel turned to shape and painted with gloss enamel.

The pouch is made with a piece of 1/32 brass wire at the top edge of the cloth, zap a goo is used to bond the cloth to the wire. Just fold the cloth over the wire, wile it is drying, bunch up the cloth on the wire so as to make it look like it has a bungee cord in side. Shape the bottom of the pouch to fit the seat try by folding the cloth under and again using zap a goo. Don’t try to make it perfect the more bunched up the better it looks.

Next, if you just happen to be at a full size glider meet, be sure to take a photo of your friends way point map. Then take the photo of the map to some one that has a laser photo copier and reduce it down to the scale size you want, then stuff it in the pouch.Now you can see how all the prep work paid off by imbedded the brass tubing into the combings. The finished spoiler and flap controls just slide into the tubing inside the combings. The yellow handle is the tow release. In the finished model shots, I have place all the graphic labels for the control surfaces.

PILOT INSTALL

One of the best pilots without question is from Axel’s Scale Pilots of Germany.  They come in 1:4, 1:3, 1:2 sizes and you can order in any color and add all the accessories you want.

Here I have given “Roy” a golf cap because he now lives in California.  I made a different seatbelt harness in dark blue nylon and a more realistic parachute “D” ring using fishing cable and clear tubing.

I also painted the hardware with “Testors” aluminum rubbing spray.  Once it dries you rub it with cotton and it looks like real metal.

 

In this shot you can see how Roy fits in his seat. He is held in by a nylon ribbon around his waist and glued to the bottom of the seat. Don’t use the harness he comes with, the plastic parts cant take much load and will break.

The seat is held in the model with one screw under the cloth boot for the joy stick. the seat back has a “Z” bent piece of 1″ wide aluminum that is epoxyed to the back of the seat, it then slides into a slot in the seat tray.

Here Roy is sitting in the model with the canopy frame in place, without the canopy.Things are looking pretty good. All seems to be in eyeball scale and we didn’t have to chop up Roy to get him to fit.