Missing box/pan brake part

[MikeC]

I am currently restoring a huge old 10ft box and pan brake. I have scraped about a ton of rust off of it so far, with another three tons left to go. I have a few broken pieces to braze up, but I am missing something and I'm not real sure what it is and how it should be shaped.

The part in question mounts on the leaf and is what actually does the bending. From pics I have found online, it is simply a piece of angle that bolts to the leaf. The place where it bolts is very obviously 2" wide, so I am thinking a 2x2x1/4" angle should do the trick. I have seen things about different radius "noses" for brakes like this. Is this in reference to this angle?

If so, do the differnet noses have radiuses machined into them or are they just offset to allow more gap between the edge of the fingers and this nose?

[Steve_in_Mich]

To the second part first. Right, the setback of the fingers from the fold leaf accounts for the bend radius. In a few instances the finger tip radius is modified to gain a predictable custom bend.

The folding leaf needs to be straight and stay straight thru the brake swing. For a brake 10' long that is a challenge even for light gage stock but assuming that the folding portion is beefed up to handle it the missing part is only an extension of the folding leaf edge (if that makes sense). If this is the case then I think the requirements for any additional angle or bar would be to align and be flush with the leaf edge and also be sufficiently finished (smooth/polished) that it doesn't scratch/scar the sheet stock being bent.

[MikeC]

Yes, you exactly interpreted my second question as to the "edge extension". The leaf itself is 1/2" thick, so it will probably be adequate for thin stuff out at the edges.
I had not taken into account the polished finish. I'll try to get a length of 2x2x1/4" cold rolled angle. That wil both strengthen and provide a better surface. I don't have any way to accurately mill and polish a 10ft length of angle!

I'm still trying to find out what these "large radius nose" parts are. I am thinking it is a piece of angle with one leg cut back so it gives a farther spacing from the fingers than max setback can accomplish. Just need to see if the edge of the leaf actually makes contact without this piece of angle on there. If it does, then that wouldn't work.

As for thickness, I think I found this brake online. They say it weighs about 4Klbs, which I certainly believe. They list max thickness on aluminum as 1/8". Aluminum is what we will undoubtedly use it on mostly, being an aircraft museum. That will probably exceed anything we will ever need out of it.

I'll try to get some pics of it as I go back together. It had some broken parts I am fixing right now. This thing is deceptively front heavy. If you pick it up with a forklift from behind, it will go over on it's face. That's what happened to it before we got it. It was dropped and mildly damaged when unloading off a truck and then sat outside for about 10yrs, so it is in pretty rough shape. I have been breaking loose moving parts, screws, and will have to braze up some big castings (one leaf hinge and the hold down handles/counterweights). It's starting to look promising, though!

[Ries]

What make and model of brake is it?
I have a lot of old catalogs for major brands, could have info on it.

The place where the bar bolts onto the moveable, bending leaf, is intended to be removable, because you might want to use different bars depending on the situation. The main purpose of this bar is to stiffen up the bending leaf, especially needed on a 10 foot brake, to keep the bend straight. You want the strongest piece of reinforcing angle you can get. On my 12ga x 4 foot brake, I use a piece of 2x2 x 3/8" angle. 1/2" angle wouldnt be overkill, on a 10 footer. 1/4" angle is probably a little wimpy. Sometimes I need to take that off, In situations where the angle would get in the way, for instance a "z" shaped profile, and then I use something with a lower profile, like a piece of 2" x 1/2" flat bar. This stiffens the front of the bending leaf without getting in the way of the sheet I am bending.

As far as the radius noses go, in most cases these are pieces that replace the fingers, and mount on the upper leaf, not the lower bending leaf. I actually built a large radius nose for my brake by taking a 4 foot piece of 4" schedule 40 pipe, and welded on tabs that fit in where the fingers bolt on. This gives you a radiused, rather than sharp bend. Obviously, any size of pipe can be used, to make a wide variety of radiuses. Roper Whitney and other manufacturers used to offer various special nose pieces for their brakes. But I have never seen one that bolts on the bending leaf- although that is not to say they may not exist.

[MikeC]

GOOD INFO! That's what I was wondering about. I will try to find 2x2x1/2 angle and maybe a piece of bar stock. The lower clamp jaw is a piece of 2x1 bar, and the bolt holes, although smaller, are the same spacing. They may have very well used a piece of the same material for the leaf stiffener (I can see many other pieces of stock used repetitively in the construction).

This appears to be a RUST brand, model FEO2... [img]/ubb/images/graemlins/tongue.gif"%20alt="[/img] This machine sat out for so long there is nothing discernable left on it. I have no idea what make it is, although it appears to be american made and is a nice big heavy piece. It is mostly fabbed up from heavy plate, but the hinges and counterweights are castings. I'll try to get some pics tomorrow. You can probably figure out what brand it is by looking at it. From the surfing I have done, identifiable differences in most brands/models appear between the counterweighted clamping handles and the hinge design.

[Ries]

Mike- do post pics- my guess is its one of 3 or 4 makes, and I or others should be able to post pictures of originally available accessories, and catalog specs. Unfortunately, most original tooling gets lost, then scrapped as mystery parts. And new tooling is unbelievably expensive, if available. For that matter, new brakes are unbelievably expensive- Even a 16 ga x 10 foot american made brake will run upwards of 6 or 8 grand, and if it is a higher capacity, say 12 ga, you are talking new car prices.

What is the museum you are restoring this for? And what kind of aircraft will you be working on?

[MikeC]

I figured this was a high-dollar piece. I'm pretty sure from looking at stuff on teh web that it is indeed a 12ga brake. It's built REALLY heavy. Probably 4-5000lbs all up. I'll try to get some pics tomorrow.

I work at the Southern Museum of Flight in Birmingham, AL. I actually have no idea what all will end up being bent on this thing. There are no big metal projects pressing, but I figure that's the best time to get this ready. No hurry.

We only had a crappy home made brake that had a sag in the middle, so I swapped some un-needed parts we had laying around the shop to get this and our Van Norman 22L mill. I didn't realize it was a box/pan until it got here, that's just so much more the better. Now I am looking for a big shear. We have a 36" Pexto stomp shear and a 4' roll slitter, but we need a big 8-10ft squaring shear to go with this brake now.

[Steve_in_Mich]

Mike C.
What's the status on this brake? Repair and photos?