Just started on the build of this classic pattern ship. designed by Owen Kampten.
I converted the Nitro engine into an electric motor. First the wings ribs were cut out and stick the pieces together. Symmetrical wing foils are nasty so all the tools came in to help.



The other half was mirror to get identical length.



Checking for wing ribs alignment. Eyeball first. Looks good



More checks


This round I decided to use Dubro nylon pin hinges so need to cut slots in the square stock. Four for each half so a total of eight slots need to be made. These needs to be true centered otherwise you get all the binding during aileron movements.



After slotting stick on the piece to the wing rib

Attachment 4770065

Making the ailerons using stock triangle but not the right gradient so more work



Cutting slots in the ailerons to receive the nylon hinges and make the bevel angle for smooth movement



According to the plans the wings have a dihedral angle so cut the Dihedral brace and test fit the brace. Everything i do must fit in tight and not too much slop, a habit from too much of helicopter building.

Attachment 4770062

Next make the aileron torque tube from 3mm carbon steel and brass bearing for again smooth movement. and solder on the threaded couplers



Now cut the slot in the Aileron to receive the torque tube


Don't forget to insert the brass bearing before you close the other end of the torque tube. Its a night mare to bend these 3mm carbon steel. But wait there is worse coming. Some pictures



Stick in the nylon hinges with extra reinforcement.


Cut the 5mm hard wood which goes to the center rib. Epoxy it to have strong bond since the wing attaches to the fuse with this hard wood, no CA for this one.

Some more pictures

This was an e-conversion of mine back in the cobalt/gearbox/nicad days- and even then it flew pretty well until I tried to go through a tree. Not as zippy as with the HB 25- but not bad. With the long snoot, you won't have a tail heaviness issue.

Sam

Nice work.

David

Always thought the Super Pacer was a cool airplane. Never got around to building one though!

You have a very nice build going here!

Ralph

Nitro please!

Originally Posted by dhal22

Nitro please!

I would love to but in my country resident are not in favour of the noise hence electric

Checking for alignment and sticking the lower spar


Checking for dihedral angle


Planking the top sheet.

After planking, glue in the servo bracket and get ready to cut out the servo pocket

Cut the landing gear support square pegs, X marks the spot for precise drilling


Sheeting the lower wing


The remaining servo bracket glue in place



Glue in the square pegs to support the 5mm landing gear carbon steel wire.

And yes bend the nightmare 5mm landing gear to the perfect right angle, pure madness and brute strength.

More pics of the lower spar and the angle joint at the center of the wing


Next the elevator connect rod and its assembly


Cut out fuselarge and make the push rod from hard wood round peg and 3mm carbon steel

Also the former for the wing attachment. A bit too short so CA comes in handy and make up for the length

Next : Glue the former in place and the triangular stock piece.

Then comes the motor mount made from 10mm ply with ventilation holes and glue it in place together with the triangular stock pieces.


Seems like the push rod cannot clear the fuse formers, so off goes some material


Then I made the ply wood to support the elevator and rudder servos


The battery tray is next


With that done, I cut the rudder and the slots to receive the nylon hinges. Marking the rudder for taper sanding

Originally Posted by Megowcoupe

This was an e-conversion of mine back in the cobalt/gearbox/nicad days- and even then it flew pretty well until I tried to go through a tree. Not as zippy as with the HB 25- but not bad. With the long snoot, you won't have a tail heaviness issue.

Sam

What kv motor and power rating? Pro size? thanks

I had about 350 watts going into a 9 x 6 IIRC. This was probably a bit more than 100 watts/lb. I liked the 9" prop on the airplane versus the 8" I'd flown with glow, but the grass had to be short to get off.

These days, I'd probably be happier with 450-500 watts and a lighter airframe. The kit wood was very heavy- this was a sturdy airplane.

Sam

Hi Sam,

I will be powering with a 480W brushless motor and start with Master airscrew 9x4 prop. Think it should be enough of power. Powered with 3s 2250 mah Lipo. Still thinking how to lessen the weight of the aircraft

The rudder requires 3 hinges 2 on the rudder and one on the fuse. Special plug was made to hold the third hinge to the fuse rear.

Planking the bottom of the fuse, cross grain.

Next comes the wing tip. Made from balsa block. Did not want to buy as it was expensive so sitck all the balance wood I have and made two blocks



Now glue the two blocks to the wings and mark the excess material to be removed



Now remove the excess material and sand to shape


Wingtip done and servo mounted with aileron in place


Next do the wing mounting for the fuse using ply. holes are drilled at an angle so that the plastic screw sits flush and nice. The two ply are join at an angle but right angled to the fuse, tricky part, and still needs to be aligned to the wing's mounting holes.




Next is to bend the 3mm carbon steel for the tail landing gear. Very hard to bend 90 degree bend and not in xy plane but xyz plane. Don't forget the brass bearing before the last bent, if not its damn........

Cut out excess material in the rudder so that the landing gear is in line with the hinges and no binding on the brass bearing.


Now a little mod to the tail wheels. To make the plane as light, I chose the plastic wheels. But it is not smooth so I added brass bearing in the wheel so that it rotates on the steel landing gear, get the idea? Ok a pic is worth a thousand words. Look carefully, you can see the brass tube. Add a drop of oil and its ultra smooth. The wheel has almost no weight and with this mod it will last a long time and more importantly it rolls perfectly straight so that take off is true.

One way to lighten this bird is to dremel out some of the center of the ribs- they're pretty fat, theres a lot of material along for the ride. But I think you're probably going down the wrong path. There are lots of purpose designed electric airplanes that will be much lighter than this one. The advantage of a glow ship is that they tend to be sturdier and withstand minor dorks and hangar rash much better. So if you've used good wood- I wouldn't sweat it. 450 watts on a 9 x 4 should be fine, but I'm concerned about the battery you've picked. At 450 watts, it's going to be drawing over 40 amps- and your flight times are going to be short. You probably want a setup in the 12-15C range to make sure that you have enough time to enjoy the flight- the airplane will carry the weight fine.

Sam