20 Ton Shop Press Brake

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So I did a lot of research into the shop press brakes and what their capabilities were. I needed to bend 1/4" plate, 10" wide at a 90 degree angle and I needed to make 32 of those bends. I couldn't find anything of someone saying they bent something like that so I thought I'd try making one and see what happens. So I just thought I would post my experience and show my design just in case anyone was wondering. As for the base and the cross section piece, I used 1/2" thick x 4" wide. The top die is 3/4" solid square stock and the base die is 1/4" 1.5" angle stock. As for alignment, I didn't have any issues. I rested the square bar up against a piece of angle and pushed the point up against the cross section and put some shims underneath the get it right in the middle. Welded a few lengths on both sides and that was done. I then welded the angles onto the base plate which fit almost perfectly so it's not difficult to make sure they're on there straight. I only welded the outside of these for obvious reasons as to not have a weld interfere on the inside.I used 1" square tube for the base and 1-1/4" square tube as the guides. I welded the 1-1/4" guides first, the put the 1" tube inside the guides and rested the top piece onto the angle, squared it, tack welded the tubing to the base, re-squared it, and completed the weld of the tubing, and it's done!The only downside to this design is it's difficult to put springs over the square tubing. I could probably be made with a little more space between the tubing and the base die to allow for a spring to fit but I personally like it betterwithout the spring as it allows for me to drop the top piece and align the work piece before I start applying pressure. As for the final result, I made the 32 bends without failure at ALMOST 90 degrees. It couldn't quite make it all the way but it wasn't obvious that it wasn't exactly 90. After all was said and done, the brake had no significant dents or dings anywhere. However, bending 1/2" solid rod had a different effect on the dies! I wouldn't reccomend it as it puts pretty serious dents into it. Overall, I spent $20 for the 1/2" plates and the rest of the materials I had as scrap laying around. I figure it probably has a total of $35-40 of materials in it. Oh yea, I was using the HF 20 ton shop press but I swapped out the jack with a Big Red air over jack that I bought off eBay for $70 shipped. I had the jack maxed out bending this plate. It couldn't complete even one more pump and when I tried to use the hand lever, I couldn't even budge it. Those air over jacks put out a lot of power! More than I can supply with the stock hand lever. Hopefully this helps someone out, just thought I'd share my experience!  Attached Images
Reply:Very interested in building one.Because of spring-back, to achieve a 90 degree bend the dies must be able to bend past 90 degrees. Here is the Swag unit:[ame]http://www.youtube.com/watch?v=-vwacbaOXjU[/ame]
Reply:Originally Posted by EcondronSo I did a lot of research into the shop press brakes and what their capabilities were. I needed to bend 1/4" plate, 10" wide at a 90 degree angle and I needed to make 32 of those bends. I couldn't find anything of someone saying they bent something like that so I thought I'd try making one and see what happens. So I just thought I would post my experience and show my design just in case anyone was wondering. As for the base and the cross section piece, I used 1/2" thick x 4" wide. The top die is 3/4" solid square stock and the base die is 1/4" 1.5" angle stock. As for alignment, I didn't have any issues. I rested the square bar up against a piece of angle and pushed the point up against the cross section and put some shims underneath the get it right in the middle. Welded a few lengths on both sides and that was done. I then welded the angles onto the base plate which fit almost perfectly so it's not difficult to make sure they're on there straight. I only welded the outside of these for obvious reasons as to not have a weld interfere on the inside.I used 1" square tube for the base and 1-1/4" square tube as the guides. I welded the 1-1/4" guides first, the put the 1" tube inside the guides and rested the top piece onto the angle, squared it, tack welded the tubing to the base, re-squared it, and completed the weld of the tubing, and it's done!The only downside to this design is it's difficult to put springs over the square tubing. I could probably be made with a little more space between the tubing and the base die to allow for a spring to fit but I personally like it better without the spring as it allows for me to drop the top piece and align the work piece before I start applying pressure. As for the final result, I made the 32 bends without failure at ALMOST 90 degrees. It couldn't quite make it all the way but it wasn't obvious that it wasn't exactly 90. After all was said and done, the brake had no significant dents or dings anywhere. However, bending 1/2" solid rod had a different effect on the dies! I wouldn't recommend it as it puts pretty serious dents into it. Overall, I spent $20 for the 1/2" plates and the rest of the materials I had as scrap laying around. I figure it probably has a total of $35-40 of materials in it. Oh yea, I was using the HF 20 ton shop press but I swapped out the jack with a Big Red air over jack that I bought off eBay for $70 shipped. I had the jack maxed out bending this plate. It couldn't complete even one more pump and when I tried to use the hand lever, I couldn't even budge it. Those air over jacks put out a lot of power! More than I can supply with the stock hand lever. Hopefully this helps someone out, just thought I'd share my experience!
Reply:When I bend something that's 1/8" thick, regardless of the length, if I'm not careful it bends it past 90 degrees. Not sure why or how that's even possible? Also my issue with the swag one is the two contact points on the bottom die are two close together. My first design I used 1" angle iron and I couldn't even begin to bend the 1/4" x 10" plates, that's why I used 1-1/2" angle. It makes sense when I think about it, I just don't know the proper engineering terminology.
Reply:http://shopoutfitters.com/store/inde...products_id=35This is a very good one.  Has a Removable die and a adjustable stop.
Reply:Some one here in the past posted up a link to a table that shows how size and shape of the die changes the force needed to bend different thicknesses. That's probably why you started to have issues with the thicker material due to the small size of the dies..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:it's all about leverage. the further it is actually  pushed from the pivot point (center) the less pressure required. going from 1" to 1.5" should in effect roughly add 50% to the capability, or reduce the pressure required by approx the same 50%. a 2" should just about double the leverage over a 1" assuming it is as ridgidmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:Originally Posted by DSWSome one here in the past posted up a link to a table that shows how size and shape of the die changes the force needed to bend different thicknesses. That's probably why you started to have issues with the thicker material due to the small size of the dies.
Reply:Well that makes sense. But why does thinner metal bend more than 90 degrees? Is that just warpage from the pressure that causes it to spring forward instead of back?