My Next Project - A Metal Brake

IMG_0647.JPG I clamped a block on my mill table as a guide and clamp each finger up against it so i can mill the end square.
IMG_0648.JPG One end of each finger is square. (I'm still waiting for the material to come for the added two fingers). The next thing to do is set up the tilt table and mill the 45 degree angle on the other end of each finger.
 
Mark
WOW! that is a pile and looks good, just needs a few hours now. You gotta to love it coming altogether.
Thanks for keeping us up on the progress.
Nelson Collar
 
Mark
Where are you, it been some time since the last word.
We just care about you.
Nelson Collar
 
Mark
Where are you, it been some time since the last word.
We just care about you.
Nelson Collar

FEAR NOT! I am alive and well. I have been working part time for a friend for the last month, helping him and it has worn me out and I just come home, go to sleep, get up and do it again. I will be done with this job in another week and life will get back to normal. I have all the fingers, but need to machine the angle on the end and drill the mounting holes. Trying to get to it soon, as I want to test drive this baby! Keep watching!
 
Today , I set up my little tilt table to see how it handles milling the angle on the ends of the fingers.
milling fingers.jpg Man, this little table works great. I was worried that not having any extra support under the front would cause a lot of vibration or the position would not hold. I got almost half of the fingers done and it has not moved on me. I am taking .020" DOC. It vibrated just a little but not enough to give a bad finish. I did set a bar upright on the table and used a woodworking clamp to hold it to the table. You can see the clamp in the photo. I did it to make sure the angle did not move.
finished fingers.jpg Here are the some of the finished fingers. I left a .050" flat on the edge and then dressed it rounded with a file.
The holes to bolt the fingers on seems a difficult problem to locate with high accuracy....so I came up with a plan....
finger drilling jig.jpg I reworked the fixture I used to locate the holes in the bar. I drilled the holes out to .375" and checked it for fit in several locations on the bar. that part is good. Next, I will mill the sides of the fixture so the hole is .500" from edge to hole center. The bottom edge of the fixture is flush with the bottom edge of the bar. I will set a finger on the bar and scribe a line. Then set the bottom edge of the fixture on the line and the side edge of the fixture flush wit the edge of the finger. then I can center drill the hole locations and drill them to .375" everything has to be right as the fingers have to fit anywhere along the bar.
Tomorrow, I will finish milling the fingers and start drilling the holes. this is all that is left on this project and then I can test it for capacity.
 
Well....the finger brake is basically completed.
completed brake.jpg I got all the fingers on it today. It was a real project. I don't have thee luxury of a DRO so I had to drill all the holes in the fingers and finger clamp bar using a fixture and my drill press. While not impossible, it is a very difficult task to keep 23 holes in perfect alignment in the bar and the fingers. Before I go any farther....:(....Yes, that one finger has an extra set of holes in it. I planned and was careful and thought it through and checked and double checked and then drilled the holes on the wrong side of my line :burned up: . While it is a purely cosmetic mistake it is still a dumb mistake that really shows. Now back to the process. it is almost impossible to drill the holes really close with out a DRO. .010" can mean a "no fit". well between little discrepancies in the tapped holes in the clamp bar and slight discrepancies in the finger holes things were hard to fit, but I got it done. If and when I remove the fingers to change setups or what ever, I will drill the bolt holes out to one size larger to allow a little adjustment and to allow for the slight discrepancies. A few of the bolts were tight going in but did go. This was a difficult project for smaller machines like mine but I wanted to show that it can be done in a small home shop not equipped with a lot of big machines or expensive fancy tooling. I am very pleased with the finger brake. The only thing I am going to do and it is a cosmetic thing, is to mark a line at the top of the fingers and cut them all to the same length. It will be a big visual improvement. So all that being said....this project is done.

The first of the week I will try some bends and see what this baby's limits are.
 
Well....the finger brake is basically completed.
View attachment 127104 I got all the fingers on it today. It was a real project. I don't have thee luxury of a DRO so I had to drill all the holes in the fingers and finger clamp bar using a fixture and my drill press. While not impossible, it is a very difficult task to keep 23 holes in perfect alignment in the bar and the fingers. Before I go any farther....:(....Yes, that one finger has an extra set of holes in it. I planned and was careful and thought it through and checked and double checked and then drilled the holes on the wrong side of my line :burned up: . While it is a purely cosmetic mistake it is still a dumb mistake that really shows. Now back to the process. it is almost impossible to drill the holes really close with out a DRO. .010" can mean a "no fit". well between little discrepancies in the tapped holes in the clamp bar and slight discrepancies in the finger holes things were hard to fit, but I got it done. If and when I remove the fingers to change setups or what ever, I will drill the bolt holes out to one size larger to allow a little adjustment and to allow for the slight discrepancies. A few of the bolts were tight going in but did go. This was a difficult project for smaller machines like mine but I wanted to show that it can be done in a small home shop not equipped with a lot of big machines or expensive fancy tooling. I am very pleased with the finger brake. The only thing I am going to do and it is a cosmetic thing, is to mark a line at the top of the fingers and cut them all to the same length. It will be a big visual improvement. So all that being said....this project is done.

The first of the week I will try some bends and see what this baby's limits are.


Beautiful Mark thanks for sharing.!
 
Attached here is a complete build article including all the photos in a PDF format. I have made a set of prints as I went along , including changes I made. I can send my edited prints to anyone who PM's me and asks for them.
 

Attachments

  • Building a Sheet Metal Brake.pdf
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I find that I often have to make the holes a little larger so everything fits.
Great job!

Ray
 
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