FILENAMES: brake1.jpg brake2.jpg brake3.jpg brake4.jpg brake5.jpg brake6.jpg brake7.jpg brake8.jpg brake9.jpg brake10.jpg brake11.jpg brake12.jpg DESCRIPTION: These are pictures of home made sheet metal bending brake. Posted by Wayne Cook . The following description was provided: ================================================================= This is some pictures and explanations of a sheet metal brake a made a few years ago. I'm also going to include the few things that need some change. First things first. Please ignore the weeds and mess. This is taken in my current construction zone ie my shop. :-) brake1 This is a overall shot of the brake. All the major part of the brake itself are made from pieces cut from a 12"x12" wide flange beam I got cheap at a auction. The legs are pieces of truck frame. The bows are made from sucker rod. In other words this was a low budget project made from what I had on hand. brake2 This shows approximately where and how I cut the I-beam to make the pieces. As you can see I cut the top of the clamp so that there would be some extra meat down where the real pressure is applied. I also cut the table so that some of the web was left to provide some meat where the table is stressed the worst. brake3 This shots gives a good look at the web left under the table. brake4 This shot shows the cross section of the clamp. Notice the extra left from the web radius and how I used it as a place to weld the back brace on. brake5 This shot shows the back of the clamp. Notice the 1" bar running across at the clamp point. You can also see the heavy adjustable bow. When I built this I wanted to be darn sure it would bend 14ga at 4'. It does this pretty well with only a little bit of flex. brake6 This shot shows the bow I added to the bottom of the leaf. The leaf is only about 3/8" thick. There was no way it could bend 14ga with only 3/8" worth of leverage (I knew that before I even tried it though I did manage to bend some thinner stuff). I think my original plan called for using the extra piece I cut from the beam to laminate the leaf. For some reason I decided instead to weld a piece of 1"x1"x1/4" angle at the top of the leaf to provide the leverage needed to bend the heavy stuff. I had to add a bow to the back of the leaf to take the bend that welding put in it. It worked great that way but the nearly 1 1/2" thickness of the leaf doesn't allow close reverse bends. I later cut the leg off the angle iron leaving about a 3/4" wide top for the leaf to help with this problem (I was in need of some tight reverse bends). When I did that the bow in the leaf got worse and overpowered the light bow I'd put behind it so I put this one in instead. At any rate based on how the brake acts when in use I think you could get by with a 5/8" thick leaf if you do something to stiffen it like this bow. However if you laminate similar to way I did you can get by with less on the main leaf but I'd just add 1/4" strap or similar instead of the angle. brake7 This shows the addition to the bending lip as I talked about above. You can also see the bow I put on the leaf. One reason I put that bow on there when building it was it allowed some adjustment of the leaf. I also felt it would help stiffen the leaf against twisting in the middle (the reason I place the bow on the outside). brake8 Here is the back bottom of the table. Notice the really heavy bow on it. You can also see how tight it was to fit the bow on the back of the leaf. Some more room needs to be planned for there in the design. brake9 Here's a shot of the toggles for clamping the bar. It also shows the back of the clamp support and the hinge for the leaf. There is a couple of things I need to change in this area. First there needs to be a adjusting bolt setup to push the back clamp support toward the leaf. It's possible to clamp it in place the way I have it but it's hard to adjust which it does need depending on the thickness of the material you bend. Second is the bottom toggle pivot. It really needs a second bolt in a slotted hole to help clamp it. It's possible to clamp it with the one 1/2" bolt that I'm using but it will move if you get too rough with it. brake10 This shot gives another view of the leaf hinge. Placement of that pivot point is one of the most critical and hardest things to get right about this whole project. It needs to be a little above and slightly in front of the table's top corner so that the leaf has some clearance with the table and doesn't slide on the metal being bent to much. I wish this was a little higher. Also note the gap between the ends of the brake and the clamp bar. Unfortunately the piece of beam I used to make this was only 47" long. I had to add to the table and leave the gaps on the ends of the clamp bar so that I could get 49 1/4" in there (needed since most sheet stock is over size by at least a little). The gap has actually proved fairly useful at times since it allows bending of a corner for a short box into it. brake11 This shows why I decided to make the toggle's easy to remove. I bent the 4' length of 14ga into the a duct (the cut off end of which is shown in this shot). If the clamp wasn't easily removed it would of been nearly impossible to get it off even with the one corner not welded (the pic shows it welded). Note that there's if a fair amount of rounding of the corners. I admit that this brake is not capable of making a real sharp corner in 14 gauge. Actually it might if I made the couple of improvements I mentioned above but it would be a real bear to make the bend. As it is it takes two people to effectively do it. I can jump up and down on the balance bars and barely manage it if I go from one side to the other but it's not a good bend when I do. One other thing I would change on the next brake is that I'd make the clamp bar at least 45deg angled back. I made it straighter than that on this one in fear that it wouldn't be strong enough. Experience has shown it to be plenty strong (most of the flex comes from the over hang of the 1" clamping shaft). brake12 This is the last one folks Honest. As you can see it's a shot of the clamping toggle. These where dead easy for me to make when I had access to the machines where I used to work. They'd take a little longer now but not much. The cams are simply 1 15/16" cold rolled slices (I used that size because there was a lot of it where I used to work). I welded two of the slices to the handles as shown and then drilled a 1" hole offset in the disc. As a earlier picture showed I drilled a 1/2" hole offset in the bottom disc to allow for adjustment of the clamp. It should really have another bolt in there since I've had it slip a few times. The toggle bars where easy for me since I had a big radial drill and a 1 15/16" shell reamer to make them with while stacked. I'd have to use a boring head now. Wayne Cook Shamrock, TX