Sheet metal brake?

[redbowen]

Other than the wing spars, what size sheet metal brake is necessary to complete the rest of the parts for the Bearhawk Patrol? In other words how small can I get away with?

[S Lathrop]

Here is a picture of a press brake I made for under $300. Something like this might be more useful than an inexpensive sheet metal brake.

I have a 4 ft. box and pan brake. It is an inexpensive import. When it comes to getting a good bend, my home made press brake is generally better.

[redbowen]

Do you have the plans for this brake?

[BTAZ]

On my LSA, outside of the spars, I did a lot of my wing part bending on a modified simple leaf brake(https://www.harborfreight.com/30-inc...ake-67240.html). Modifications can be seen in the photos.

I had lucked out on Craigslist for a 40" 3 in 1 shear, brake, and slip roll. I mainly used the shear when building the wings. I used all of the functions when at the fuselage stage for the boot cowl, cowling, trim pieces etc.

It certainly isn't "as good" as separate machines but it is "good enough" given most work is in Aluminum plus it takes up a minimum amount of floor space.

I think the more typical 30" versions would have been too short,

[old pete]

I just got finished building this and it works really well.
have bent up stainless steel on it so far and it did a good job. It's 8 ft long and ran about $200 to build.
very happy with the way it came out and the bends I have made with it so far.

[Bcone1381]

Brad,

I have the same 30 inch harbor freight brake. I want to know more about your modifications. Confirm that
-the clamping bar that came with the brake is used.....
-that its held secured to the heavy duty L with magnets.
-That the heavy L is held up with springs
-That the heavy L can be lowered and forced down with threaded rods at each end.

Am I missing anything else?

[BTAZ]

Your observations are correct.

The springs were just some valve springs I had laying around

There are some Allen screws on the back of the clamping angle to allow the setback to be adjusted. That;s why I used the magnets to hold the foot against the clamping angle; it allows the foot to move for setback adjustment without having to come up with slotted brackets and such.

I would probably use a Harbor Freight magnetic tool holder(https://www.harborfreight.com/18-in-...der-60433.html) instead of the individual cabinet magnets as HF always has free coupons for them.

I reinforced both original brake angles by welding another angle(maybe 1"x1.5"x.125" cross section; was just scrap I had laying around) to the backside to basically change them into rectangular boxes instead of angles.

Worked great for bending all the wing rib attach angles as well as most of the steel brackets(wing and landing gear attach and such) for the fuselage.

You might want to look at modifying the clamping angle in size or position a bit to allow a tighter or taller "C Channel" to be made without interference.

C channels are not really viable;e on a press brake

[Dan R.]

Picture of a 8' brake built from plans. Very good brake. Picture of Dallas Shell and Dan Ward and me ( I took the picture bending the spar webs for Bearhawks. We bent spar webs for 3 Bearhawks.
Dan R.

[Chris In Milwaukee]

Picture of a 8' brake built from plans. Very good brake. Picture of Dallas Shell and Dan Ward and me ( I took the picture bending the spar webs for Bearhawks. We bent spar webs for 3 Bearhawks.
Dan R.

Is that the Mac's Machine brake?

[Dan R.]

Is that the Mac's Machine brake?

Yes, and we like it. We change it a little by using cold roll steel for the bed plate and clamping bar. Very heavy and strong brake.

[Chris In Milwaukee]

I bought those plans some time ago, but dang it all if I can find them...

[keefer66]

Rehash of old thread, 30" leaf brake is plenty big for balance of build (not counting spars)

[sjt]

Steel parts can be bent with bars of cold rolled steel (onlinemetals.com). The edge can be filed down and rounded over. I used a 20 ton press.

I also got a northern tool Klutch Box and Pan Brake — 48 1/4in. At the time they went for about $400 on sale. Keep in mind that any sheet metal brake will have to have modifications to be used for making airplane parts. The setback on a stock brake is not enough to include a "shoe"

I did a write up on the kinds of modifications required:
https://eaabuilderslog.org/?blprojec...&listcat=tools

Dave Bottita did a youtube video on his modifications to a different brake:

https://www.youtube.com/watch?v=Wys5zGe5bss