Wing

I just bought a sig twister and the leading edge is not formed. Is there a tool to shape it? Do I just start sanding and hope for the best? I need a little help on this. Thanks

Master Airscrew makes a real hand razor planing tool. Cost is under $10 I think. Tower Hobbies should have it. I use mine all the time. I think Great Planes makes an electric plane tool also.

Hi John,
I have a drawer full of modeling planes. My current favorite is this one from Lee Valley:

http://www.leevalley.com/wood/page.aspx?c=2&p=56750&cat=1,41182,41188

It's a bit more expensive, but the blades last longer, and the plane itself is more versatile than others.

>I just bought a sig twister and the leading edge is not
>formed. Is there a tool to shape it? Do I just start sanding
>and hope for the best? I need a little help on this. Thanks

Howdy Froogy, I can tell that you've never carved many Hand Launched Glider wings.
Same principle really, mark a centerline and then mark two adjacent
lines to the center, giving yourself enough space to carve(wood plane)
an arc. the two adjacent lines should be a reference to your airfoil
nose radius. Of course you cut and sand a bit oversize for rough shaping,
then fine sand to proper shape. Just proceed slowly it'l work for you.

Tony G

My first Sig Twister I sanded the leading edge nice and round.

My second Twister I did not sand the leading edge round, I left a sharp 90 degree edge.

Several people told me it would not work with a sharp LE. One person said, the wing will develope strange vibrations. Several others claimed I would have other problems.

GUESS WHAT. It flies great. Best flying airplane I have ever had.

>My first Sig Twister I sanded the leading edge nice and
>round.
>
>My second Twister I did not sand the leading edge round, I
>left a sharp 90 degree edge.
>
>Several people told me it would not work with a sharp LE. One
>person said, the wing will develope strange vibrations.
>Several others claimed I would have other problems.
>

The fact that you, *seemingly* got away with it, doesn't make it a good idea.

Brett

I was hoping Gary's suggestion was an April 1 comment!

>I was hoping Gary's suggestion was an April 1 comment!

New here, are you?

Brett

Brett,
your kinda fiesty today?

After you get it rough shaped, you might try Juan's slick sanding jigs. I made three (different radii), and like them a lot

http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=290116&mesg_id=290116&listing_type=search

Larry Fulwider

Here's one that's buried in that aforementioned thread. If Derek and Dan like it, it'll work real well for you. Steve

[photo not recovered: 3300.jpg]

Steve Helmick
Renton, Washington
USA

I assume this is done after building the wing,

>I assume this is done after building the wing,

If you mean sanding/carving, the answer is yes. That's what makes it easy to get the shape right.

With the Twister, if you are using a shaped sanding tool, be careful that you don't dig into the ribs by accident.

It is useful to cut out a template in a piece of sheet balsa from the leading edge/airfoil shape from the plans. Makes it easier to check if you are getting the shape right. Sight down the leading edge to see that the edge is straight.

FWIW,
when I sand the leading edge to shape, I run two inch masking tape, ( the good stuff ONLLY) on top of the ribs,, right behind the acutal leading edge, that way I can get rather aggresive without messing up the ribs while sanding.

Good idea on the tape. Thank you.