size of sheet metal brake?

[Greenley]

Hi,
Per vans instructions I am building a sheet metal brake like diagram 5-5 to finish my elevator trim tabs. Trying to figure out what size to build the brake, is it needed again for the wings, and if so what length? I would hate to make one that ends up being just a little too small for later needs. Any thoughts appreciated.
Bill Greenley
RV-10 Empennage

 

[Auburntsts]

I made mine out a 8ft 2x8 board that I cut in half so my brake was 4ft long and I used 3 door hinges to attach the 2 pieces together. Anything over 3ft is fine as the trim tabs are around 2 1/2 feet long IIRC. You don't use the brake anywhere else in the build so I wouldn't spend a lot of effort on it.

 

[Rick S.]

The brake will make or break your tabs as far as getting them straight. I used 2 1x4 oak strips, 3 feet long. Use oak to make your blocks for the bends as well. It is the wood of choice for bending the skins and the close out tabs. I used a piano hinge to hold the pieces together and some scrap aluminum angle to make handles. The brake only squeezes the bend on the T.E. By using the smaller wood you can use your fingers to keep the tab in close to the hinge, grab the handles and lean into the tab to make the squeeze. Yes it cost 30$ to make and it's a one time use but total up the cost of two new tabs if they warp and it's a trade off.

 

[Greenley]

Thanks

Thanks for the info and advice.
Bill Greenley

 

[jwilbur]

Warning

Bill,

One mistake I made was squeezing the tabs too much in the brake. Don't flatten them completely as I did. It was a real pain to get them unflattened so that they didn't pinch in between those foam ribs. I had to press into the crease all along the length a sanded wedge of wood until the tabs were unsquished enough.

 

[Auburntsts]

One way to avoid squishing it flat is to insert a small diameter wood dowel at the trim tab trailing edge where the bend is when you're using the brake.