Jet Fighter Target Drone (JFTD) for FRCC

[Ken Park]

I've promised to do a future article for FRCC magazine and the plane is an updated version of my fast little (JFTD) - The update will be the built up wings vice the original foam ones!

So follow along and be first to see the build in action!
Recently a new modeler wanted to know how to make ribs - This is how I scratch build them from plans.

[Ken Park]

I cut out the ribs needed from the plans
I glue them down on the 1/8" balsa and trace the outline in ballpoint pen
I cut the ribs out 1 by 1 and trim them very close too the ball point pen line
Using a disk sander I sand down to the very edges of the ball point pen.
Then using a scrowl saw I cut out the notches for the spars etc.
Last I mark the center holes and burned them out using a dremel tool!
All the ribs are now finished!

[Ken Park]

I started out making the front 1/4" Leading edges x 2
Then stripped the rear 1/4 x 1/2 Trailing edges x 2
Both the LE and TE have a 1/16 sq stringer glued on the centerline so the LE and TE have a guild to keep the wing straight

Next came 8 x 1/8sq front & rear top/bottom spars

I pinned the TE stock over the plans and then the bottom 1/8 spar - Then each rib was glued into place.

Next came the rest of the top/bottom 1/8" spars and finally the LE was glued into place.

Repeat for the other wing pannel

Lastly I glued the wing pannels together with the rear 1/8 x 1/4 ply wing joiner epoxyied into place

[Dave_Sawatzky]

I assume that hammer in the picture is for making "fine" adjustments...:)

[Ken Park]

The hammer is yes for fine adjustments LOL - But I do use it to drive my T-pins into the building board Iam using!

Last night I finished up epoxying the front/rear 1/8 x 1/4 ply center spars.

Today I've added 1/32" rear top/bottom sheeting
Note also the 1/32" sheer webs adding strength to the design
I added the 1/4" center section same height as the top of the ribs. I was able to make a few marks from the original built fuse to see what area's would need triming later on.
Lastly I added the top 1/32" front sheeting. - eeek ran out of 1/32 sheet need 2 more sheets to finish job!- Fred! hold 2 sheet for me eh!

So far its building nicely!

[Ken Park]

here they are

[Ken Park]

Ok I guess it was wrong of me to think that almost everyone had seen me fly this little jewel in 2 years. Its a great flyer with a fantastic glide. It can be flown as rocket ship going warp-6 or it can go thermal hunting. go high turn off moter and thermal all day! Done both love it either way!

So here are a few pics of the original with the foam wings!

Tom and other E-boys what would be the motor/battery lipo's set up for this model wich normally fly's on a OS LA .15 using 7-4 prop! Iam seriously thinking of steping over on this model! Its got a 40" wingspan and 8.5" cord!

[Ken Park]

Ok I've been to Fred's and got my extra sheets of 1/32"

Today I finish sheeting the wing and next I went for my razor plane and trimed off the extra 1/4" Trailing edges so that its flush with the airfoil shape
I then did the same for the 1/4" Leading edges after the razor plane I used my sanding block to get my LE airfoil shape made - in this case its a razor share edge.

Last thing today was the center 1/32" sheeting and I added the Y-harness for the 2 HS-81 servo's that are to be soon mounted!

Look very carfully and hard at the balsa on the floor - I think I see Jesus! or cloads - I don't know? I cleaned up the mess its too late to make money on E-bay.

[Ken Park]

The Center TE rear section has been added
Next came the 1/8" ply wingtip blocks - designed to save the wing tips if draged.

Aileron stock was 1".25" wide - hard as iron and as heavy - yuk! - I've decided to top hinge the aileron so the bottom edge was cut upward at 45 degree's and some lightning holes were needed also! - Area without hole is for Aileron control horn -

I'll try and get aileron servo's mounted soon! - Wing will be finished by then.

[Ken Park]

The Ailerons! were made up from 1/16" ply plates fitted into the bottom of each wing - I used some 1/4" ply to make servo saddles to screw the servo's into securely. I then cut out the slot for the servo arms. Lastly I used 1/8" ply corners to screw the plates into so they fit flush with the bottom of the wing. Only thing left was the hook up of the wires to the Y-harness

[RT Models]

Bravo Ken,

Glad to see you got to it! Looks super.

Been busy down here just got the Beaver (http://www.rtmodels.com/de_Havilland_Beaver.htm) done at long last....only so many hrs in a day :(

Have a good one :)

Thanks,

[Ken Park]

Saturday was raining so it was easy to get building! - thanks Mark for compliments. - Technically it looks like the built up wing will be heavier than the original foam one!

I got started on the fuselage - the two 1/8" sides are joined too the center two ply bulkheads.

The rear 2 1/8" balsa bulkheads are added and the tail gets pulled together.
I don't have the E-motor yet so can only build the rear end till its available in April soon I hope.

The fake jet exhaust are is built on top of a 1/4 x 1/8 balsa stringer and then sheeted in with 1/32" sheet. This was easy to do! - So that about it till parts get in. Iam going after the H/V-stab next I guess.

[Ken Park]

:eek: Well it looks like Iam going back to step 1 in the building project!
I totalled my E-version of the JFTD on Sunday at the Rideau RC Flyers E-meet! It was fun while it lasted! All I can say was the crash was 99% pilot error with 1% of the strong gusty winds help pushing me over/down.

Hey did anyone get a pre destruction picture? - I don't have any?

I think with a little bit of work - the laser cut version can be quickly be ordered up! - I had a few good coments on what they did see of it flying.

[cgroves]

Ouuch, that is too bad. Problems in the sneaker joystick interface module have probably crashed more models than anything else ;). Thats why I always take a picture *before* the first flight. Are you going to build another one? I was looking forward to seeing that one fly.