anyone tried building the home made 8 foot metal brake

[fairchild1934]

Frank---- are you saying that your bend radius in the bent part is bigger than the shoe in the brake ? so you had to make the shoe a smaller radius to get the part to the radius you wanted ?????

[sjt]

The plans update:
Helps avoid tin can on top of airfoil.

http://bearhawksafety.com/Patrol/february2020.html

I do not know why but this picture is smaller then the original picture sent out years ago. I suppose anyone with a new set of plans would have a better drawing



The repository for change notices specific to patrol is at:

http://bearhawksafety.com/Patrol/patrolengineer.html

stan

[sjt]

My first shoe was made out of steel strap used for binding large stuff together. It did not have to be - that was just what was on top of my junk pile. I then tried to use rolls of roofing flash material. That got expensive because once you bent a 10 foot shoe you could never transport it. You would have to make another shoe the next time. After enough screw ups you have lengths of 2024 strips that can be made into nice shoes with the correct bend radius for subsequent work. The steel and 2024 shoes can be transported without damage.

I also have one of those 4 foot brakes that can be used for quite a bit - so the shoes come in various lengths.
shoe1.jpg


A very important feature of a brake is the ability to set it back. A brake requires one set back to make a shoe. And then you have to set the brake back again to bend the next piece of material over top of the shoe.
In my case I bent another group of various lengths of 2024. The two shoes one over the top of the other gave me the bend radius I wanted.

I then used tape - you can see the clear tape on the brake - to hold shoes in place for bending the spars and other lengths of 2024.
shoe2.jpg


I only chimed in on this post because I personally drove a hundred miles to a EAA chapter that had a real brake. As such having a plan to bend everything you can think of saves gas.



A real brake can be set back as required for making different radius bends
three.jpg






There are things that require a large brake.


I got a lot of mileage out of a 4 foot brake - but I had to modify it to emulate the feature of a real brake.
one.jpg


two.jpg

[sjt]

On the patrol the flap requires a 10 foot brake. The spar stiffener and trailing edge are over 8 foot 8 inches. Probably you do not want to bend the skin that length.

Again, my problem was that I had to drive a long way to get hold of the brake.
I needed to have all of the material and a plan on the sequence of bends to make the shape.

This was the sketch I made for the order of operation to bend the flap stiffener
f1.jpg

g1.jpg


You need a 10 foot brake to make the initial bends of the trailing edge, and you need a 10 foot brake to crush the trailing edge down to finish the shape - as per Bob.

I used a drill rod to help the forming process.

t.jpg


I could not find a good picture, but the leading edge stiffener for the wing required a 10 foot brake. Hard to make on a brake, but it can be done.
c.jpg

Also, the flap spar requires a 10 foot brake
spar.jpg

[Frank]

Thanks Stan. Great photos and documentation. So, that's one thing the DIY brake has going for it: you don't have to travel any farther than the local steel yard. Plus, you don't have to have it all figured out in advance. It's good to make the distinction between models: the LSA for instance only requires an eight foot brake and only has a trailing edge on the ailerons. I sort of wish skin stiffeners had been added to the plans.

[fairchild1934]

I am still doing ribs so far-- so I have not decided fully if im going to do a 4 place or a patrol. ( I have 4 place plans) May be engine dependent--

Did i understand you to say the wing spar pieces are a little over 8 foot ? which would mean making the brake 10 feet ????? Why do the flap parts need to be made on a 10 foot brake--- aernt they like 5 feet long ???? (the piano hinge material comes in 8 foot lengths-----)

Tim

[sjt]

the patrol flaps are 8 foot 8 inch +1/8=104.125

The spar, trailing edge and stiffener need a brake longer then 8 feet.
More recently Bob recommended installing a stiffener on the wing top leading edge.
Most people would not bend the skin on a 10 foot brake.

There is no piano hinge.

fla.jpg

I am a fan of a real brake. I myself drove over a hundred miles to get my hands on one - at an EAA chapter.

If you drive that far you want to do as much as possible even if that part could be done on an 8 foot brake.


I learned from other builders the value of buying the aluminum in 12 foot sheets.

sheetcount.jpg

[fairchild1934]

the piano hinge is the core of the home made brake. They come as 8 foot units. I will look at the 4 place flaps and see how long they are.... I have not gotten to flaps and flap parts yet.