# Brake Fingers



## francist (Oct 9, 2016)

So I've got this sheet metal brake -- a 36" Chicago box and pan -- that I've had for years. Got it in pieces from a buddy, cleaned it all up and put it back together, built a stand for it and there it has sat. Reason: no fingers. 

D&K doesn't make them anymore for this machine, and used ones are pretty hard to come by. And, truth be told, I really haven't needed the darn thing that much anyway. Then a few months ago a little favour came up where the brake would come in handy. I cobbled a temporary finger together just to do the one-off, but then I got to thinking I might make another stab at getting this thing up and functioning. So, how to make the fingers with my less than comprehensive equipment inventory.

In order to get the basic cross section with minimal stock removal (no milling machine), I opted to make a sandwich of two pieces of cold rolled 1018. Ultimately there will be 17 fingers in all with widths ranging from 3" to 3/4", but I figured that it would be easiest and most reliable to keep things square and aligned if I built the fingers in longer lengths. So I made two sticks, each about 18" long, and put three cap screws in each to keep them together.




With each stick firmly sandwiched, I did my lay out for all the finger widths and hole positions. Depending on the finger width, there would be either one or two 5/16 cap screws to drill and hand tap.



After a bunch of back and forth between the bench, drill press, and tapping rig they're all screwed together nice and solid. For the narrower fingers that would only have room for one cap screw I drilled and drove in two roll pins (split pins) to keep the sandwich halves from rotating. At least that's my theory.




Over to the Keller now to lop the sticks into the finger widths. This Keller was in sorry shape and headed for the dumpster when I snagged it. Works nice now, at least for the limited demands I place on it.




The Keller makes a nice cut, but I wanted the fingers all squared and parallel, so I trimmed up the edges on my little shaper. The mini-pallet fixture plate is nice for repetitive clamping and unclamping.




The underside of the top leaf on the brake has a groove that the fingers kind of hook in to, so the back edge has to be fitted accordingly. Rather than do the whole thing on the shaper (slow) I used the bandsaw to rough out the shape. In woodwork this would be called a rebate. I used the mini-pallet again and set it at a bit of an angle to match the blade descent to cut the first leg on the rebate. The second cut in from the end I just did with a hacksaw.




Back to the shaper to clean up the rebates. I managed to get them all pretty consistent, so I was pleased about that. 




And here they are on the machine for the first time. I still need to make the clamps to hold the fingers in position, and of course do the final shaping on the noses. That will need a bit more set-up and jigging, so this seemed an appropriate juncture to take a breather. I'll follow up when I finish them off (if they work!)



Thanks for looking!

-frank


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## mikey (Oct 9, 2016)

Hey Frank - nice job and nice post! Your pics really helped to understand what you did. 

Amazing what some guys can do without a milling machine!


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## brino (Oct 9, 2016)

Very Well Done!

Great use of multiple other machines to bring another back to use.
That Keller power hack-saw looks really nice!

Thanks for sharing this.
-brino


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## gr8legs (Oct 9, 2016)

Thanks for that! You have inspired me to do the same with my brake!

Stu


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## Tony Wells (Oct 10, 2016)

When you said you didn't have a milling machine, I thought you were going to have to do all the work with an attachment on the lathe. Not an optimum setup, by any means. But one that works, given its limits. THEN you said the magic word.....shaper. It all turned to gravy then. Shapers were what did basically all the flat work before mills came along. You were in no trouble at all. You have the drill press for hole making, so you have it covered. Good job.


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## pineyfolks (Oct 11, 2016)

I like your shaper chip shield. It's a lot nicer than the cardboard box I use.


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## francist (Oct 11, 2016)

Thanks, it's a piece of face shield material that got replaced in the one that I wear. The setup isn't perfect -- the little buggers still seem to hop either over or under the shield -- but it helps. Need to make a bit more versatile mount as well but for now it works. I have an auxilliary piece that I can clamp onto the top when the chips get really jumpy. It's made out of, wait for it, CARDBOARD!  

-frank


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## francist (Oct 29, 2016)

This has got to be a first for me -- finishing a project in the same month I started it in!

Anyway, here I am back at the brake fingers. And yes I was right -- there was a whole lot of jigging around and setting up to get the final steps accomplished. I also figured I'd take the bit of a break from the actual finger pieces and spend a little time making the clamps. There's not a lot of complication here, basically just some 1-1/2" X 1-1/2" angle with one leg trimmed down and a bolt hole or two. Once again, I laid them out in sticks so I could hang on to them better for cutting and also cut the shaper time in half or better. They look nice and spanky here because they've just come out of the muriatic acid bath to get rid of the mill scale. Does a real nice job, and pretty fast too.




I cut the one leg down just roughly using a cutoff wheel in an angle grinder. Again, works fast, and for primary sizing it didn't need to be fancy. Then I trimmed them to final on the shaper. Back to back clamping cut down on the time too.



Here's the pile of finished clamps. When I started building the fingers I number stamped the pieces by finger in case I needed to disassemble them, and I carried that through to the clamps as well. Not that it really mattered, they're not a precision fit, but it gave me a tremendous feeling of reckless abandon to be able to toss them randomly into a pile without regard for order knowing that they were numbered.   




Ok, back to the fingers. More layout, drilling, and seemingly endless tapping for 5/16 - 18 bolts.



Over to the little red bandsaw again to cut the snouts off. The angle is just slightly less than 45 degrees, not that that really matters either. At least for my anticipated needs anyway.



I'm impressed by the quality and consistency of cut that these little things can produce if you spend some time setting them up properly. And going from one operation to the next is so much nicer if cuts are close to the line and not all over the place. 



Shaper time again. This is where the set-up took some time. I ran through multiple ways to hold the parts to get the cut, and while this one that I settled on isn't the most efficient for the shaper it is the one that I felt most confident in with respect to holding the parts firm. I also wanted a high degree of repeatability here -- it would do no good if at the end of this whole rigmarole the fingers were all different. Yes it's a box and pan brake, but if you can't line all the fingers straight enough to use as a plain brake you've really missed the target. At least in my book.




By flipping the squarish chunk of aluminum end for end on the pallet I could do the primary angle first and then a final setup for a secondary angle at the very tip. Only about 60 thou wide, it's like a micro bevel on a chisel. I'm probably overkill on my strap clamps, but whatever. It's not pretty when parts slip on a shaper.



A bit of grey Scotchbrite to knock the fuzz off and then put the pieces together. 



All in all I'm really happy with how it worked out. Now I just need a project to see if it works!

Thanks for looking, guys.

-frank


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## hman (Oct 30, 2016)

Beautiful results!  Congratulations.


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## C-Bag (Aug 20, 2021)

Really nice work and outcome Frank! Lots of inspirational stuff in the use of your set ups. And folks wonder why we spend so much time making tools for our tools. Your pallet system is absolutely brilliant. Lots of work but totally worth it. I really need something like that.

I am contemplating some kind of upgrade to the press brake on my 3n1. Mostly some kind of mod to the clamping set up and making a solid one piece upper die for long brakes. The 3n1 needs as much help as possible with rigidity especially for full width bends. Doesn’t help that there is a lack of precision in the fingers, the clamp and cast iron frame. If the thing wasn’t so close to what I need for the space I have I’d bail and find something else.


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## francist (Aug 20, 2021)

Thanks @C-Bag Tony, I appreciate the kind words.

Yup, the setups are almost the most fun part of the whole adventure and with small machines one often needs to get even more creative. I use that little pallet for lots of stuff — it can go from the shaper to the bandsaw, the hacksaw, or to the milling machine without missing a beat. Super handy.

Good luck with your press brake upgrades, you do some nice work in sheet metal yourself.

-frank


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## C-Bag (Aug 20, 2021)

Thanks Frank.

 I’m glad you posted the link to this thread because it was before I joined here so I had no clue about it. And it somewhat pertains to what I’m contemplating with my 3n1. I get my inspiration for mods through use as I come up against the shortcomings. First I have to figure out if it’s my inexperience or the machine 

I’ve always got to be aware of overthinking something. It can not only complicate the process it can make it so complicated the improvements never happen. So getting confirmation I probably don’t need special steel for my limited use is another thing off worry list.

I also am in the same boat in that i have small machines so have to be very creative in finding solutions. 

Did you ever put your box and pan to its full use? BTW good save as that is definitely something I would have a hard time walking away from.


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## FOMOGO (Aug 20, 2021)

Very impressive work on the fingers and clamps. I'm sure that now that you have it up and running the future uses will present themselves. All my metal bending has been confined to clamping things to a chunk of H-beam with a piece of angle iron and bending with a mallet, but I'm continually on the lookout for a decent shear and brake. Mike


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## francist (Aug 20, 2021)

Oh yes, I have used it although not for really big stuff. Most recently (ok, a year ago) was some formed COVID shields for our cashier stations. I used 060" polycarbonate (Lexan) which cold forms really nicely. I need to spend more time at it and hopefully get my head more aligned with the order of doing things. Dollars to doughnuts, my first bend is always the wrong one and I end up hooking myself for the last one! Oddly enough, sewing is helpful with somewhat similar constraints on how to achieve certain shapes.


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## brino (Aug 20, 2021)

francist said:


> This has got to be a first for me -- finishing a project in the same month I started it in!



I've done that........but it wasn't the same year!


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## Suzuki4evr (Aug 20, 2021)

francist said:


> So I've got this sheet metal brake -- a 36" Chicago box and pan -- that I've had for years. Got it in pieces from a buddy, cleaned it all up and put it back together, built a stand for it and there it has sat. Reason: no fingers.
> 
> D&K doesn't make them anymore for this machine, and used ones are pretty hard to come by. And, truth be told, I really haven't needed the darn thing that much anyway. Then a few months ago a little favour came up where the brake would come in handy. I cobbled a temporary finger together just to do the one-off, but then I got to thinking I might make another stab at getting this thing up and functioning. So, how to make the fingers with my less than comprehensive equipment inventory.
> 
> ...


Nice thread Frank,but looking at the thread title.........I thought you're working for the mob see. Even your name fits...frankie fingers??


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## C-Bag (Aug 20, 2021)

francist said:


> Oddly enough, sewing is helpful with somewhat similar constraints on how to achieve certain shapes.


This is not odd at all. It is for those of us who don’t sew, but there is so much about metal forming and sewing that is similar. Metal does what cloth can’t do and that is shrink and stretch without cutting out or adding, within reason. But you can get a feel for how the project should be done by making paper patterns. You can see where things need to shrink and stretch along with sequence of forming.


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