TECH.. Bending thin walll tubing

This first bender has not yet been perfected, but i figured i would show it to all of you anyways since it is tech week.

I started with some 3" wide 1/4" flat stock, it was convenient since the bend diameter i needed was 3". I cut the flat stock to length and cut/ground the radius on one end. Then drilled on hole at the center of the arc, and two more evenly spaced for clamping through our die material. In this case we used wood for the die, the wood failed while bending and i plan to try UHMW plastic for the next round.

The roller that bends the tube is a 2" hard plastic caster wheel, i disassembled the caster, drilled the hole out to 3/8", through bolted it, chucked it in the drill press and used a half round wood rasp, and metal file to cut the groove in the wheel.

The arms for the roller are 1 1/2" x 3/16" flat, with a long length of 2" tubing for leverage.




So far I have only been able to complete a 90 degree bend with this set up, but it appears that with the use of a stronger material for the die it will be able to produce a complete 180. I forgot to mention this is 5/8 x .065" steel tubing.

 

This is the method i use for bending tubing for bicycles, I know it's not on topic, but I'm sure it may come in useful for some body. I started by making the dies out of 2 x 12 wood. I start by laying out the 4 mounting holes and the radius of the bend I need. These dies are through bolted to my workbench, and another peice of wood is used to hold the tube against the die.



So far the tightest radius i have used is 15" with is the shorter bent section at the end of the pictured tubing. The tubing begins to collapse slightly at this radius but it is effective enough for a bicycle frame. I have discovered that to prevent kinking the curve has to be constant, as any change in radius mid bend would cause the tubing to start kinking. The tubing pictured is 1 1/8 x .065" wall steel tubing, bent cold.

 

Premium, I am now inspired to try to do something to make my cheepo bender work. I was skeptical of the end rollers and single die when I bought it. And of course it didn't work for exhaust. I tried pool sand, was told that filling the pipe with sand will make it stay in the die and not kink. Didn't work for me, so the bender has set in the corner since.

 

Another way to help minimize kinking is to fill the tubing with sand.
Just cap one end(spotweld a cap on there, fill with sand(fairly packed)and cap the other end.
It is a little tedious to do but if you have to get a tight bend without a kink it will do it.

 

Salt works much better then sand.You can cap the ends with wooddowels,easier and faster.
Great lil benders.I have a bunch like this I use all the time.....Shiny

 

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Premium, I am now inspired to try to do something to make my cheepo bender work. I was skeptical of the end rollers and single die when I bought it. And of course it didn't work for exhaust. I tried pool sand, was told that filling the pipe with sand will make it stay in the die and not kink. Didn't work for me, so the bender has set in the corner since.

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You have to make sure the sand is fully compacted, by tapping the tube vertically on the ground, before welding the second end on. There is a distinct change in tappety tone when it gets as packed as it can be. Keep topping it up as it settles, then carefully weld up the other end without allowing any sand to fall out. I tried it a few times and it worked okay for me.

 

If you decide to weld both ends on.
once you get them on where you want them.

Tap the center of each end with the ball end of a ball pein hammer to pack it a bit tighter.
Garth

 

How does small guage square tubing go? Have you tried it in your bender?

Steve

 

This is a great post but you can go to your local harware store or if you have a Home Depot and get a 1/2, 3/4, 1" emt bender and bend just about whatever you want from emt, rigid pipe, thin wall etc. It is very easy and cheap. Bend 90, saddles, offsets, etc. This is what I use

 

Flattysteve, I have tried square tubing with no luch so far. I did order some UHMW plastic for use as a die, and when I have that I am going to try a die and roller that dimples the bent inner and outer sides of the tubing as it is bent.

Yeah the emt benders work really good, but i use these methods for bend radii that aren't possible with the emt benders.

 

OK thanks, I tried to do it quick and easy, couldn't have been "tight" in there, just filled. Also used pool filter sand, next time it'll be masonry.