View Full Version : sheet metal brake progress

11-09-2014, 01:07 AM
Thought I'd show a couple images of my bender project. This is the bottom die assembly partially assembled. Looks pretty crude at this point, but a quick explanation- an obvious part is the bottom die, the horizontal part near the top of the assembly. The vertical angle iron pieces are the front guides for this sliding assembly. The column will be in two pieces, one each side of this assembly. The top jaw, the punch, will assemble between the column sides, and thus is created a guideway for the die assembly. When the column is assembled, two more pieces of angle will be attached to the bottom assy and will become the rear guides. Those will also pin to the bottom jaw.

http://s25.postimg.org/4f9r2vri7/bottom_die_partial_assembly.jpg (http://postimage.org/)
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At this point I have used some thinwall 3/8 tubing cut into 1 inch lengths as temporary assembly 'pins'. I slit them down one side so they would close up just enough to push into the holes. Being a tad over 3/8, this was needed so they'd fit the holes.

Here is a close-up of one of them in place.

http://s25.postimg.org/805mm3w1r/roll_pin_detail.jpg (http://postimage.org/)
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When I'm satisfied that everything goes together correctly, with just enough play for the die assy to slide up and down, I'll push these out with sections of regular roll pin. With all these replaced by roll pins, next step is to turn up some plugs with a bit of a head on them to press into the ends of the roll pins. This should make it solid like rock.

The bottom die will be operated by pushing up on the bottom of it, and that pushrod will be movable. If I'm bending a full 5 inches, the rod will be positioned 2-1/2 inches in from the front. If I'm bending only an inch or two, I would position the rod closer to the front. This method will take the strain off the guideways, which will then only be keeping things in alignment.

I'll need to have a pretty solid fixing of the top jaw to the column, and once the columns are made I'll be re-inforcing that area. There will be a method of angling the top jaw slightly to compensate for flex and eventual misalignment after some use.

11-09-2014, 09:15 AM
Hi Darryl
Your links don't point to any pictures. They both just point to http://postimage.org/

11-09-2014, 11:20 AM
I have one a race car builder made & used 2 snow plow cutters & has a pipe that swings up to do a 11/4" radius & a swing out power beader. He did a great job.

11-09-2014, 03:29 PM
Your links don't point to any pictures. They both just point to http://postimage.org/

They show for me- anyone else not see the pics? Tried a different photo hosting site since Pbucket has gotten to be a PIA.

11-09-2014, 07:45 PM
The pictures are now visible.

11-10-2014, 01:41 AM
Cupple more pics- mostly done, seen here beside its brothers.

http://s25.postimg.org/hllvgjzzz/three_benders.jpg (http://postimage.org/)
images (http://postimage.org/)

This is a better pic- shows the jaws better. The top jaw extends out the back and will get a brace to the column to keep it square. Once the alignment is right, the metal block at the top will be bolted in place, then welded. That will finalize the column and add some support for the upper jaw. If I get a chance at work tomorrow, I'll make up a plywood base for it. With that attached, I'll work on the pedal and actuator bar.

http://s25.postimg.org/hmvt9z1tr/open_ended_bender.jpg (http://postimage.org/)
free image hosting (http://postimage.org/)

One of the final steps will be to cut some roll pins to length and insert those in place of the ones you see here. Not sure what I'll do with the new pins in place- I was going to machine some inserts and press them into each side of the roll pins, but now I'm thinking I should try to find some bolts that might be a tight fit inside the roll pins. Bolted together, it should stay tight- but the roll pins could flex if they aren't totally supported inside. The other option I thought of was to make the press-fit inserts, but drill and countersink one side, drill and tap the other side. I'd be using smaller bolts, but at least they would keep the inserts in place.

11-12-2014, 01:05 AM
Whooeee! Having my fun now- got the brace parts cut, everything aligned, holes drilled. Got a stand under it and the parts are assembled. At this point it's put together with my home-made temporary roll pins. The plan was that if everything is good, these pins get replaced with real roll pins. At this point I have 5 or so put in- about 8 to go. The fun part was getting it up and into the press. Awkward to say the least. Not sure if I should post a pic of this- the safety nazis would come looking for me-

Here is the whole contraption precariously set up clamped to a 2x4 to level it up in the press. The plywood base is in the top left corner of the picture.

http://s25.postimg.org/qgj1g2xa7/roll_pin_pressing_setup.jpg (http://postimage.org/)
post image (http://postimage.org/)

Four pins visible here- this is the top of the bender. The rest of the pins might be easier to do- maybe not.

http://s25.postimg.org/l6e2osd1b/top_pins_done.jpg (http://postimage.org/)
screen capture windows 7 (http://postimage.org/app.php)

Once it's back on its base I'll show another pic.