stunthanger.com

Building Tips and technical articles. => Building techniques => Topic started by: Bootlegger on November 26, 2012, 06:12:40 AM

Title: foam wing
Post by: Bootlegger on November 26, 2012, 06:12:40 AM

  Guy's when you are building a foam wing and installing a balsa leading edge, what method do you use to shape it to a symetrical all the way from root to tip?

  Thanks a lot, Gil
Title: Re: foam wing
Post by: Robert-Jan on November 26, 2012, 07:29:35 AM
I Like the igor way with 2 templates.

Greetings Robert-Jan
Title: Re: foam wing
Post by: Bill Little on November 26, 2012, 07:47:02 AM
Brother Gil,

Some plans have a template shown on the plans.  If not, make one.  I use a Solingen razor plane to begin the shaping, taking an amount off one side then the same from the other side.
Then finish with 40 grit then finer.  I finish with a 22" long sanding block and 320.  I "roll" the sanding block over the edge, so to speak.

I think you should always use a template and your eyeballs. ;D

BIG Bear
RNMM/AMM
Title: Re: foam wing
Post by: Avaiojet on November 26, 2012, 08:08:12 AM
Gil,

Bill's advice is good advice, I work the same way. Shadows can reveal the shape of the LE as you progress.

I also make jigs. Nothing complicated as you can see from the photos.

As Bill said, you can get templates of the LE or the full rib, off the plans. Simply cut the jig in a scroll saw and apply sticky sandpaper inside. Has to be correct.

One thing though is the importance of a center line on the LE. Careful not to sand it away in the beginning.

Last thing. I sometimes run a length of masking tape along the edge of the LE block on the sheeting. Keeps the sheeting from getting sanded.

I've always used light 1/16" sheeting.

This wing is in limbo. it's for a electric DF model I will eventually get around to.

What's your project?

Good luck!

Charles
Title: Re: foam wing
Post by: Robert-Jan on November 26, 2012, 10:25:07 AM

Look at part 7

How to build wing - F2B Max (controlline) Part 1.
http://www.youtube.com/watch?v=DH2t_5BkZGE

How to build wing - F2B Max (controlline) Part 2.
http://www.youtube.com/watch?v=XkyHPHNV9kA

How to build wing - F2B Max (controlline) Part 3.
http://www.youtube.com/watch?v=YlkrRm-z34I

How to build wing - F2B Max (controlline) Part 4.
http://www.youtube.com/watch?v=b9oAA_SlQQo

How to build wing - F2B Max (controlline) Part 5.
http://www.youtube.com/watch?v=8Wj46B3-YXc

How to build wing - F2B Max (controlline) Part 6.
http://www.youtube.com/watch?v=BlgBJZxIlaw

How to build wing - F2B Max (controlline) Part 7.
http://www.youtube.com/watch?v=p0ad4L2-NYk

How to build wing - F2B Max (controlline) Part 8.
http://www.youtube.com/watch?v=6aUm_KAeNnY


Greetings Robert-Jan
Title: Re: foam wing
Post by: Avaiojet on November 26, 2012, 10:58:29 AM
Gil,

I finished this LE this morning. Exactly as suggested.  Doesn't have to be attached to foam, the shaping is the same.

There's much more left to do with this particular stab, but a start is a start!

Charles
Title: Re: foam wing
Post by: MarcusCordeiro on November 26, 2012, 11:25:17 AM
I guess that's why a moulded LE is much better.

Marcus
Title: Re: foam wing
Post by: Robert-Jan on November 26, 2012, 11:47:05 AM
Marcus,

How do you mold a stab LE?


I guess that's why a moulded LE is much better.

Marcus
Title: Re: foam wing
Post by: dirty dan on November 26, 2012, 12:58:37 PM
Marcus,

How do you mold a stab LE?



Install square piece of stock. Run stab LE past suitable cutter mounted in router which itself is mounted to router table.

Dan
Title: Re: foam wing
Post by: FLOYD CARTER on November 26, 2012, 01:15:12 PM
Any heavy cutting on a balsa block with a high speed cutter will almost always cause a serious warp in the wood.  Table saw, router:  no good.   I get acceptable results using a band saw at low speed and a "skip tooth" blade.  Problem there is you can only do straight cuts.

F.C.
Title: Re: foam wing
Post by: MarcusCordeiro on November 26, 2012, 01:23:33 PM
Marcus,

How do you mold a stab LE?




I thought the thread was about wings...
I'm about to shape a Stab LE of the Magnum I'm building.
Sanding and eye-balling I guess.
Of course, you don't have a stab with 60" span, so it's much easier to get a better shape on the stab LE.
And when I build the wings, I'll have to sand too.
If you have the option, go with the moulded LE.
It's more work, but worth it.

Marcus
Title: Re: foam wing
Post by: Willie Johnson on November 27, 2012, 05:45:14 AM
Does anyone know what type of glue is being used in the video to join the balsa sheets for the skins?  It looks like some type of polyurethane.

Thanks,

Willie
Title: Re: foam wing
Post by: Bootlegger on November 27, 2012, 06:26:09 AM

  Willie, I use regular model glue for my skins as it can be sanded easily.  Also I use Duco cement as it is the same type glue, and works as well..