Brake Fingers

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
 
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.
 
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
 
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.
 
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.

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.
View attachment 137275


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.
View attachment 137276

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.
View attachment 137277


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.
View attachment 137278


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.
View attachment 137279


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.
View attachment 137280


Back to the shaper to clean up the rebates. I managed to get them all pretty consistent, so I was pleased about that.
View attachment 137281


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!)
View attachment 137282

Thanks for looking!

-frank
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Nice thread Frank,but looking at the thread title.........I thought you're working for the mob see. Even your name fits...frankie fingers??:D
 
francist said:
Oddly enough, sewing is helpful with somewhat similar constraints on how to achieve certain shapes.
Click to expand...
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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