|
|
This is a close up picture of harbor freight tube bender machine with a SWAG set of angle bar dies installed.As you can see there are two pieces of metal in the die's mouth1. a 1/4" thick piece of bar to fill up the void as much as possible2. a 1x1" by 1/16th thick piece of angle bar that has major wavy distortion due to the bending forces on it.I tried sticking in an extra 1/16 thick piece of bar in there so there was absolutely zero slack, but then the machine wouldn't roll.Obviously the wavyness is causes by slack in the die, how do I fix this so there is no distortion? I was thinking of maybe putting a piece of thin plastic or some kind of springy material like hoop velcro to fill up the space and hopefully get less distortion. the gap is about 3/8" wide.I also tried 1.25x1.25" by 1/8" angle bar and that was a disaster, then I put TWO pieces in at once and they filled in the 3/8" slot better and their tendency to bend in towards one another was mitigated.Any tips on how to bend angle bar are appreciated.
Reply:It's not uncommon when trying to roll angle that it will warp like that, I also imagine your scratching the heck out of that aluminum, even with a 3 or 4 thousand dollar rolling matching you will get the same effect. The way I've always done it was to take another peice of angle and tack weld it to the first one to form a square tube, roll it how you need to and then cut all the tack welds apart, works like a dream....for me anyways
Reply:The only way to do it well is to have tighter fitting dies. Upping the thickness of the angle will help too. Also, that looks like aluminum, most likely T-6. Just buy a lower T grade and it will bend easier, or use steel.Last edited by walker; 02-23-2013 at 09:12 AM.
Reply:thansks for the responses. Kind of disappointing to buy $180 set of dies with 3/8" jaws to find out they don't work good for my purposes. I might try the tacking trick. How many tacks per foot would you do for 1/16th wall angle?how many tacks for 1/8" aluminum angle.it is t-6 grade aluminum. I'll ask my supplier if they carry a lower grade. But honestly it is EASY to bend, my problem is the distortion. Maybe I should propane torch the entire length of angle bar and see if that makes it easier to manipulate?
Reply:You need to understand WHY the angle is doing what it is. When you go to roll the angle the way you are, one of two things has to happen to get it to do what you want it to. Either the flat surface has to stretch, or the vertical surface has to shrink, to get the results you are looking for. What is happening is the "weaker" area is giving up 1st. The tall, thin, unsupported vertical leg is buckling under the force being applied to it. Normally a tall structure is stronger than a flat structure, so the flat would want to stretch. ( take a ruler and try to bend it in the tall vs the flat orientation). However what is happening is that the vertical leg can't take the force because the height to width ratio is to large for the material, so it buckles under the stress. The solution is to either fully support the vertical piece with the proper die so it can't buckle, or go to a thicker piece. The idea of building a "box" tube out of the angle accomplishes much the same thing as going with a different die. The "open" edge of the angle gets supported by the 2nd piece of angle. However when you roll the box, you'll end up with one "positive", and one "negative" piece. ( one with the vertical leg to the outside and one with the vertical leg to the inside). That means you will have doubled you material cost because the 2nd piece is "scrap" unless you need that angle rolled that way.I can guarantee they probably didn't design that 3/8" die with bending 1/16" thick alum angle in mind. Wrong tool for the wrong job..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:Roll a piece of material to form the radius (smaller for spring back) you need, then form it solid. Then bump the angle around the pattern to form the radius. Twisting will need to be addressed as you go. It could be done by hand for that gauge material.
Reply:Remember aluminum is sticky it will be difficult to turn if you get too tight. Wonder if teflon would help?Process sounds wasteful.
Reply:Actually swag sells it as a UNIVERSAL. Angle bar dieAfter using it I think that description is misleadingNext week I will try some plastic filler and if that does of work I'm gonna get a custom groove milled |
|
发表于 2021-8-31 22:06:33