IMAC JTEC 2.7m Extra 300CS

[Alky6]

Talking with Al Young this week, they are working on a new prototype scale airframe. It is the Ashcraft DR-109 (radial version) with the round fuse. Pretty flipping cool! Should add some great variety to available kits to build for somethig different! Here is a link to the ashcraft page and some pics of construction progress.

http://www.ashcraftaeroworks.com/newprojects_landing.html

 

[Alky6]

The right wing is now done (well...sheeted). It came out about 2.5 oz heavier than the left. Guess I got a little carried away with the epoxy! Next will be the elevators and I believe that will conclude my bagging operations. Then it will be time to fit the wing to the fuse, set the incidence on the wing and elevator and start cutting out ailerons, rudder, and elevators. Actually getting a number of parts going. Have some JTEC cans coming and hopefully soon a DA 100L.

 

[Alky6]

I cut out the rear former out of 1/4"x4" balsa. Then squared up the sides and glued it in with Titebond. Also got a J&J tailwheel and got the holes drilled, extra support and tee nuts glued in. I also added some tri-stock around the perimeter to help with some glue area. Probably not needed, but I had visions of ripping out the tailwheel
.

 

[Alky6]

Working on the canopy/hatch. Set the hatch mounting tabs in the hatch bottom plate. Thougtht I would be pretty sly and just mearly set them to the outside to locate the mounting holes through the fuse. NOPE. Good thing I only drilled one to check. That plan would have worked great if the fuse sides were parallel to the centerline of the fuse. So, I went back to the way the instruction suggested. LOL. Found the center of the mounting tab and used a square to measure to the outside of the fuse, then down to the centerline of the hole. Filled the botched hole with a dowl. Good to go. Added the longerons and stringers. Also glued in the tee nuts on the tabs.

Set the turtle deck in place to set the correct rear hatch former angle. When I added the 1/4x1/4 stringer that runs the length of the hatch it had quite a bit of twist incorporated into it so I use a piece of 1/4x 1-1/2 spruce with some spring clamps to hold the back end in place while the glue dried.

The sheeting is proving challenging. Got carried away and broke a piece. Decided I should probably use some amonia and water to soften up the 3/32" sheeting. Figured it might be best to wet fit and let dry in shape before gluing. Used a 3/4x3/4 aluminum angle to hold the bottom end of the sheeting flush with fuse. One problem I am encountering is where the sheeting is extending beyond the F1 former. It is ultimately supposed to be flush with the back and top. I think I am going to add some 1/8" shim material under the hatch so the sheeting can run wild over the top. I don't want to sheet the hatch without it being installed for fear of adding an unnecessary twist into it.

 

[Alky6]

Got the hatch glued and roughed out. So there are some hard bends in the bottom part of the hatch. I did this great job of using amonia to get the bend and let dry. Then, bonehead manuever, started gluing and pushin and "SNAP" break the balsa. Had to walk away. Come back later and looked at what I was doing, and thinking "man, that stuff really warped in the middle!" I then saw my marks and realized I rotated the sheeting a 180 so that my nice dried bend was in the middle instead of the edge.... crap. So I cut and sanded the old sheeting off and went and picked up some replacement balsa.

Because the front of the hatch is flush with the top of F1 former and butts up against it, it made trying to lay the sheeting in difficult. So I shimmed up the bottom of the hatch 1/8" and clamped it to the fuse to hold it straight and square. This allowed the sheeting to run wild over the former making the process much much easier. Oh well, all part of the learning process and part of what makes this stuff so much fun. The fun being figuring out how to overcome a hurdle...LOL.

 

[scruffmeister]

Looking great! I have one of these pencilled in for my next build... but have to ship it to UK Thanks for a great build thread...

 

[jtec/radiowave]

Paul,

Second times a charm!! LOL!! Its taking shape and looking real good. My friend dropped off the DA 100 and ignition for you. I will make up the canisters next week and get it all shipped out to you.

What you can do for the canister prep is take some lite balsa and sheet the canister tunnel on the sides and bottom of the tank mount. You will need to have an aft air exit for the heat to exit.

Do you have a scheme picked out yet?

I'll be in the shop preping for NALL and doing some sheeting on Kevin's MX over the weekend but the PHONE WILL BE OFF!!! LOL. I need some quite time to get work done on the planes.

Al

 

[jtec/radiowave]

Looking great! I have one of these pencilled in for my next build... but have to ship it to UK Thanks for a great build thread...

Sounds like a great idea!!

Al

 

[Alky6]

Looking great! I have one of these pencilled in for my next build... but have to ship it to UK Thanks for a great build thread...

Thanks! Hope you'll do a build thread as well? I have heard that some in the UK (and elsewhere) have a different means of sheeting the wings? Would be curious to hear about that.
Thanks again!

 

[Alky6]

Paul,

Second times a charm!! LOL!! Its taking shape and looking real good. My friend dropped off the DA 100 and ignition for you. I will make up the canisters next week and get it all shipped out to you.

What you can do for the canister prep is take some lite balsa and sheet the canister tunnel on the sides and bottom of the tank mount. You will need to have an aft air exit for the heat to exit.

Do you have a scheme picked out yet?

I'll be in the shop preping for NALL and doing some sheeting on Kevin's MX over the weekend but the PHONE WILL BE OFF!!! LOL. I need some quite time to get work done on the planes.

Al

Thanks Al. Can't wait! No scheme yet. Still undecided. Have plenty of time to figure that out....LOL.