Adjusting tube bend angles (oops. . .bent those tubes too far). . .can it be done???

atomicjoe23

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So I know if you fall short of the bend angle you need it is really straight forward to put the tube back in the tube bender and bend it further. . .

. . .what happens if you bend a tube too far (say like 15-20*)? Is there a way to relax the bend (with driver safety/rollcaget integrity kept in mind) without destroying the tube?

Thanks!
 

BTFfabrication

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Usually your time and frustration ahead just making a new tube. If it’s mild steel tubing and it’s over bent a few degrees is do-able, but if it’s 15-20* over bent like you say, it’s much better to just start over.
 

atomicjoe23

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That's what I figured, but I thought I would ask. . .first time this has happened to me so it's not something I've tried before. I figured a lot of people on here have more experience than I do and would have a better idea of the feasibility than I do. . .
 

BTFfabrication

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In a shop I used to work at we had a tube that we welded onto one of the steel posts in the shop. We could slide a piece of tube in there and massage it back to shape; within reason of course. That was usually reserved just for mild steel though.
 

atomicjoe23

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It is 1.75 x 0.120 wall mild steel tube. . .

. . .we could heat the tube to make it a little easier since it's mild steel and not chromoly we wouldn't be affecting it's strength.

If it comes to that I'm thinking we would have to slide into the hitch of one of our diesel pickups to have a strong enough holding point to massage the tube back.

I guess worse case scenario is we try it and see what happens; if we have to bend a new tube we aren't out anything other than a little bit of effort. . .shouldn't take more than a half hour total to figure out whether it's going to work or not. . .
 

BTFfabrication

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Don’t heat it. It will kink if you try and bend it back too much even cold. I say give it a go, but at the same time m.s. tube is so darn cheap it’s hardly worth it at the same time, if your time is worth anything.
 

jon coleman

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new one if safety involved.at least u got a good patern now to get next one right & a future shock hoop, bumper , ect.hmmmm, glad im not the only one who bernt a piece of 1.75 .120 .cept' my engineeing faux - paus was crho- mo$$$
 

85yota

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I have unbent tubes 5deg or so by sticking the end in a truck hitch but any more than that I just redo the tube.
 

Sonofed

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I have a specialty DEbending tool I made with two 2”x .180 tubes, wrapped some 1/4” thick rubbers and they work pretty well for minor adjustments
 

atomicjoe23

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I thought I had updated this. . .we were able to unbend the tube and use it as a template for the new tubes, but the tube was completely unuseable as an actual part of the roll cage. . .

We were really careful, filled it full of sand and only bent it a little at a time and it still deformed the tube significantly. . .
 

vegasloki

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On the build I'm doing now and the last one I did I bought a stick of the thinnest wall REW in the same diameter as the DOM. I cut sections of that and used them for the fit templates. With import DOM at near $6 /ft and homegrown at $8/ft (year and a half ago I paid just over $3/ft for the same material) it's cheap insurance.
 

BTFfabrication

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It will get you close. But DOM or chromoly has a lot more spring back in the bender. So your going to have to bend the good tubing farther to get the same bend as your mock-up piece of mild steel.
 

BTFfabrication

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Or used emt conduit for mock up?
If your somewhat skilled at what your doing you shouldn’t need to makes full mock-up part/tubes. However if your going to, I think it best to use something close to the material that your going to use for the final part. I have a bunch of sample bends that I can use as a template for how much bend will work best for certain parts. But I don’t ever make a full part out of something cheap and then copy it with DOM or something, that’s twice as much work in my eyes!
 

atomicjoe23

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On the build I'm doing now and the last one I did I bought a stick of the thinnest wall REW in the same diameter as the DOM. I cut sections of that and used them for the fit templates. With import DOM at near $6 /ft and homegrown at $8/ft (year and a half ago I paid just over $3/ft for the same material) it's cheap insurance.
WOW, that is expensive. . .I just paid $5.45/ft for 1.75" x 0.120" domestic locally 2 weeks ago. . .
 

gwizz

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the easiest way ive ever seen to fit cage and what not is to bend a 90* or greater small piece of tube and mark the where the dye lines up on that. then you use that with a piece of scrap tube or tape to determine where your bend radius starts/your strait tube lengths ect. kind of hard to explain on the interweb but if you take a 90 and start jamming it where you want to put tube youll see pretty quick how the tube can and cannot be routed also where it needs to be bent to clear "X"
.
 

vegasloki

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It will get you close. But DOM or chromoly has a lot more spring back in the bender. So your going to have to bend the good tubing farther to get the same bend as your mock-up piece of mild steel.
The bender is a Model 3 air over hydraulic so the precision isn't dead nuts on. Between that and my Trick Tools protractor there is a fair amount good old fashion crafting the angle. I've got spring back calcs in the library for most everything I've bent (except this new stock) but still finesse and measure to get what I need. I do this mainly to check my Bendtech pick points for things that are multiple bends in a radius. Bendtech has paid for itself several times in both time and material.

WOW, that is expensive. . .I just paid $5.45/ft for 1.75" x 0.120" domestic locally 2 weeks ago. . .
I may have you confused with another guy but aren't you in the So Cal high desert? If so where did you get it? With all the off road race shops in town I'm surprised there aren't more places to get DOM or 4130 though I don't think any of them build their own trucks. This latest batch is ARRIS, a US company but from what I've found is imported from India. Before that I was getting Wheatland from Totten in Azusa. By the time I drive there and back (about 8-9 hours) and pay for gas (about $150 at right now pricing) unless I'm getting several sticks it doesn't make sense and I haven't needed that in few years. This was 3 - 23' sticks. Hopefully the tariffs will come off steel and prices will get more toward what they were. Fortunately I still have a fair amount of 2", 1 1/2" and 1".
 

atomicjoe23

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I used to live in SanDiego. . .I have since moved to Washington state on the Kitsap Penninsula. . .

. . .cost of living, cost of gas, government, traffic, etc. were all getting too ridiculous down in So-Cal; WA isn't perfect, but most everything is an improvement over the SanDiego area (weather may be the one exception). . .
 
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