rolling leading edge

prkaye · #1 08-13-2006, 01:02 PM

On the training project, I'm at the point where I roll the leading edges of the two skins up to meet each other in a curve. There's no indication in the instructions on how much to overlap the skins at the leading edge... the more you overlap, the tighter the curve. I've gone with a 3/4" overlap... is this about right?

robertahegy · #2 08-13-2006, 01:39 PM

For the training project, that should be fine. In the empennage, when the LEs are rolled, you will be mating predrilled holes, so the overlap is already determined. The key in the excercise is to have you practice the rolling process and to avoid creasing the skin near the spars so the roll is smooth, without a noticable transition from flat to curve.

Roberta

G-force · #3 08-13-2006, 02:13 PM

Thats about what I used for my practice kit. I pre layed out and drilled my rivet holes on one side. Then rolled the edges, pushed it into position by hand, and held it with duct tape while I drilled the holes and clecoed it together. Ifyou have an edge roller, this is a good project to practice with it on. Otherwise the overlaping skin buldges out between the rivets.

prkaye · #4 08-14-2006, 07:18 AM

what's an "edge-roller" ? I've just been using pieces of dowel and duct-tape.

rv8bldr · #5 08-14-2006, 08:18 AM

Quote:

Originally Posted by prkaye

what's an "edge-roller" ? I've just been using pieces of dowel and duct-tape.

Hi Phil

Missed you yesterday at the EAA 245 chapter flyin breakfast at Carp.

You will need one of these....

http://www.averytools.com/p-45-edge-rolling-tool.aspx

Cheers

G-force · #6 08-14-2006, 08:18 AM

"edge forming tool"
http://www.cleavelandtoolstore.com/products.asp?dept=56

johngoodman · #7 08-14-2006, 04:53 PM

Phil,
I have the Avery style and it works fine. If you are in a hurry you could just build one. All it is is a round piece of plastic (you could use wood) for the palm of your hand, with two sliding closet door rollers screwed on with just the right amount of gap for a sheet of aluminum. Frankly I think a piece of soft wood with a thin saw cut in it would do the same thing.
John

prkaye · #8 08-15-2006, 07:06 AM

looking at that avery tool, I'm trying to figure out how it is intended to be used... do you run the edge to be bent, lengthwise along the edge between the rollers? This somehow bends the edge down?

rv8bldr · #9 08-15-2006, 08:04 AM

Quote:

Originally Posted by prkaye

looking at that avery tool, I'm trying to figure out how it is intended to be used... do you run the edge to be bent, lengthwise along the edge between the rollers? This somehow bends the edge down?

That's right. You apply a little bending pressure as you move the roller along. This will put a slight bend in the edge of the aluminum. The trick is to not over bend it.

The reason for using this tool is that when you rivet a skin on, the edge of the skin can bend outwards just a bit. By pre-bending the edge inwards a little bit, that tendancy is eliminated. Next time you are out to the hangar I can show you.

Cheers