After mulling about and reading how others did their press brakes, I decided to launch off on my own. This thread is a progression of the build, but most of the parts are already made.
This press brake is designed to fit in the carriage of my Carolina 20 ton shop press. I started out with a railroad tie plate that was used in a turnout. In retrospect, I should have just bought some 3/4" or 1" plate instead of surfacing a hot-rolled tie plate. Other pieces of scrap came from some railroad materials. (A benefit of doing business with the RR!)
Anyways, I decked the tie plate and machined notches in it so it would fit in the carriage nicely without moving.
I tried to get an idea of what kinds of materials and thickness of the material I would be working with. After that, I made up a spreadsheet with the bending equations to play trial-and-error with the bending radii, gap, and other parameters, and tried to size things for the 20 ton press.
I settled on a 1.5" gap in the die and a 0.125" radius on the punch. The working length is 18". It will do full length bends (1020 steel) through 0.125" thickness material. It will do 12" at 0.25" thickness, and 6" length at 0.375" thickness.
In order to get the 0.125" radius on the nose of the punch, I machined a v-groove in the punch and stitch welded some 1/4" tool steel rod into it. This gives a nice consistent radius, and the tool steel will wear better than the hot rolled plate. The punch is made from some hot-rolled plate, prox 3/4 x 3" x 20". On the end is some round tubing from Mcmaster, that has bronze bushings in them, where they ride along on 5" stripper bolts (socket-head-shoulder-bolts) with die springs to hold the punch up.
The die is just two pieces of square tubing for now. I need to weld them in, bolt them down, whatever. I also need to make some kind of a backstop to get accurate bends on longer length materials.
On the way home tonight, I had a good idea for doing sheet metal. Certainly in sheet metal work, it's wasteful to have flanges longer than you need them. The 1.5" die gap doesn't help things there, so I determined that I could machine a "drop-in" die. The drop in die would have a smaller v-gap that would have an appropriate radius and dimensions that would work for coining bends. That idea is in progress though.
So far I probably have about $80 bucks invested (mostly parts from mcmaster)
Anyways... on to the photos...
Machining the taper on the punch. (prior to the v-groove for the tool steel)
Punch on base plate prior to welding
Thanks for looking,
Darrell
Tacked up punch on bushing tubes
This press brake is designed to fit in the carriage of my Carolina 20 ton shop press. I started out with a railroad tie plate that was used in a turnout. In retrospect, I should have just bought some 3/4" or 1" plate instead of surfacing a hot-rolled tie plate. Other pieces of scrap came from some railroad materials. (A benefit of doing business with the RR!)
Anyways, I decked the tie plate and machined notches in it so it would fit in the carriage nicely without moving.
I tried to get an idea of what kinds of materials and thickness of the material I would be working with. After that, I made up a spreadsheet with the bending equations to play trial-and-error with the bending radii, gap, and other parameters, and tried to size things for the 20 ton press.
I settled on a 1.5" gap in the die and a 0.125" radius on the punch. The working length is 18". It will do full length bends (1020 steel) through 0.125" thickness material. It will do 12" at 0.25" thickness, and 6" length at 0.375" thickness.
In order to get the 0.125" radius on the nose of the punch, I machined a v-groove in the punch and stitch welded some 1/4" tool steel rod into it. This gives a nice consistent radius, and the tool steel will wear better than the hot rolled plate. The punch is made from some hot-rolled plate, prox 3/4 x 3" x 20". On the end is some round tubing from Mcmaster, that has bronze bushings in them, where they ride along on 5" stripper bolts (socket-head-shoulder-bolts) with die springs to hold the punch up.
The die is just two pieces of square tubing for now. I need to weld them in, bolt them down, whatever. I also need to make some kind of a backstop to get accurate bends on longer length materials.
On the way home tonight, I had a good idea for doing sheet metal. Certainly in sheet metal work, it's wasteful to have flanges longer than you need them. The 1.5" die gap doesn't help things there, so I determined that I could machine a "drop-in" die. The drop in die would have a smaller v-gap that would have an appropriate radius and dimensions that would work for coining bends. That idea is in progress though.
So far I probably have about $80 bucks invested (mostly parts from mcmaster)
Anyways... on to the photos...
Machining the taper on the punch. (prior to the v-groove for the tool steel)
Punch on base plate prior to welding
Thanks for looking,
Darrell
Tacked up punch on bushing tubes
