any of you guys have some tips for making accurate bends in conduit? im looking to make a circular bend in some 3/4" conduit,,,i tried wrapping it around something round, but the radius is not precise enough....is there a better method, that would be more accurate? also,,,how do i bend 1" square steel tubing? i need to fabricate some body bracing for the shoebox, and im not sure how to bend this stuff without kinking it....
If you need the same radius as a conduit bender, you are golden. If not, rework a rope pulley with a catch and handle. For the square tube, cut it in half, bend and reweld.
the radius is actually close to 4 1/2 feet,,i should have specified that,,the tighter bends are no problem with the conduit bender,,,
the key to the sqare stuff is to releave the iner wall eather with a cut ora paice of 1/4" rod between the tube and the bender
I have seen people jig it up with blocks screwed to plywood, the radius that you lay out is a bit smaller than the radius desired because of spring back. I had a bunch of electricians doing this for a commercial job I was doing and they had to conform to some large columns. Granted these were long pieces. I am speaking about conduit not sq tube. I have a friend who does railings and he uses a press to bend sq tube. He sisters two 2x8's together and cuts out the shape with a jigsaw. He mounts the bottom section of lumber in the press frame and attaches the top to the ram. He sticks a section of sq tube in there and the press crushes the two halves together and bends the tube in the process. I don't know if I explained it well enough to help........
Good explanation ******* - You can do the same thing (if you don't have a press) by making the same wooden jig, putting the sq tubing between the two concave and convex pieces. then gradually tighten with a ****load of woodworking clamps, bar clamps, pipe clamps, etc. Takes longer, since you have to tighten each a llittle at a time and sneak up on it! Experiment first, since the springback will cause the radius to be a bit bigger, so you have to anticipate this when you make the jig.
the issue of rod n custom with the red metalflake coupe on the cover has a whole article on this in it
Like you, I was looking for ways to bend square tubing, but the best suggestion I heard was to use unbent Tubing for your straight runs, then make Templates and fabricate the corners out of sheet-it sounds harder than it is. I could not come up with a good way to bend Square Tubing either, so I bought a Pro Tools Bender-wished you lived closer, I could help you-
This link has some good info on form size Vs part size. http://metalgeek.com/archives/2005/05/01/000047.php
its called a concentric bend. you figure out the radius of the bend you want. Than you figure out the cir***frene of said circle with that radi. than multiply by the degrees of bend you would like and divide that number by 360. this number will give you a starting and ending point for your bend. now draw evenly spaced lines between your starting and ending points. (the more lines you have the smoother your bend will be.) take the toal degrees of ben and divide that by the number of lines you drew.....this gives you how many degrees to bend at each line...... and thats all there is to it. it takes some practice but once you get it you wont forget it and I have no idea on the square tube
We made a bender out of old casters. It works great! The arc can be adjusted by cranking the single caster. Works on flat, round, or square
ohh 4.5 feet here we go 4.5feet =54" 2*54*3.14=339.3" lets say you wan 25 degrees of bend 339.3*25/360=23.56" on your conduit put a mark and another mark 23 9/16" away from that. now half way between these marks put another mark. and half way anotermark and halfway another mark you get the idea. when you get to around 1" apart count them up and divide that number by 25 and that how much you have to bend at every one of those marks. keep a very close eye on your bend as it will dog very quickly if you dont
for the square body bracing you can nail some boards onto a bench or heavy board, leaving a few inches gap, then lay the square across the void and hit it with a rubber hammer, it will gradually work a curve into the tube, you can do this with the round too but making a perfect circle may be hard, the body braces im ***uming will be changing radius so its just a matter of trial and error, flip it over or hit on a flat bench to remove too much curve good luck Zach
The latest R&C has a good article on bending tubeing. The trick with square is to lay a piece of round stock in the die. It collapses the inside flat on the square.
Chaz, I've had this idea going around in my head for about 3 years now. How well does it work on 1" square? How tight a radius can you get? I had all sorts of ideas in my head to make that work but none as simple as that. I love it. Pete
Chaz, How did you fix your crank handle to the caster? I'm sure it's simple enough but I just can't see it. Pete
I found, that with the 1" square tubing, it seems to matter where the weld seam is. I don't remember which way worked best, but it was less likely to kink depending on what side the weld was on. Good luck
I saw Gene Winfield bend 1" square tubing by just smacking it on the floor a few times. Puts a nice gradual bend in it, although it wouldn't work for a tight bend.
Chaz, How far apart are the upper casters (probably better to ask how far apart the axles are) and what size caster did you use I figure if enough guys pester you about it, you'll sit down and draw something up
Here's a bender I made for my 1" sq tubing. I used it to replace all the wood in my 31 Chevy. It looks like the same basic design as Chaz's bender, just flipped up vertical.
That's more like what I was envisioning. I suppose it's the same as Chaz's really. Great work. I'm gonna make one. Are those bottom rollers custom built or are they off the shelf. the lip on the sides is good. Pete
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