# How To Straigten Small Brass Tubing?



## countryguy (Jul 27, 2016)

Hi all.   Is there a trick someone can point out to me to straighten this pipe out? (pic below).   Searched and see tube straighteners, but I cannot remove this.   So it's Heat it, or some trick I'm clueless about.
TIA!!!


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## woodchucker (Jul 27, 2016)

I would think annealing it would make it easier to bend.
To prevent kinking, maybe wrap it with some copper wire if you can't get a bending spring on it.
if you can get the tube out of the piece it would make it easier to do it.


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## JimDawson (Jul 27, 2016)

I'm thinking a little heat might be the best.  Just heating the brass anneals it.  Brass is hardened by working it.


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## Ulma Doctor (Jul 27, 2016)

+3 on annealing.
as a suggestion fill the tube with a piece of wire just smaller than the ID of the tube (post anneal).
it will prevent tube collapse


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## Tony Wells (Jul 27, 2016)

Annealing would be appropriate. I think I would take a piece of round stock just shy of the ID, and shape a full radius end on it. Working all hand held, tap lightly and put a little pressure in the "straightening" direction. Use a little grease on the half-ball shape and it should not take much force. Make the end of the rod as smooth as possible. The rod will keep the tubing from collapsing and keep it all round. You shouldn't have to anneal it beyond the initial process. That may not be absolutely necessary, but since the temper is unknown, but we do know that it work hardens from bending, we can safely say it is harder than it originally was and there could be a risk of cracking if it was already at a hard temper. Don't heat it and try to work it while hot.

How straight is "straight" in this instance? How much pressure is on it? It looks like a bit of gas plumbing from a welder. Is that a solenoid operated valve it goes into?


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## Inflight (Jul 27, 2016)

Wouldn't it be easier to just cut the old tube, ream it out and sweat in a new, straight tube?


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## countryguy (Jul 28, 2016)

GReat stuff folks!    Best of both worlds here.   1) I took to you guys first so I did not ruin in.  2) Heated the joint and the thread-lock or whatever melted and I took out the brass pipe from the device itself.   I can remove the ground strap and run it into a straighter now or try some heat.

This is an S45 Plasma torch head.   It's part of my 2nd 3D printer project to make a new plasma Torch head assy for my machine torch.  (now a lonely hollow aluminum tube).   The old head was a molded plastic head also.   Parts were a cool $180..... Unless you have Fusion360, the H-M forum, and a 3D printer.... Then it's about $45    That above needs to fit into this:  (pics below)  And it's really a close fit.  We'll see!


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## chips&more (Jul 28, 2016)

When you straighten a bend. The outside radius compresses and the inside radius of the arc/bend stretches. I would ONLY heat up the inside radius of the bend because of this. Heating the outside also, would probably cause a failure in uniformity. Stuffing a rod down the ID doesn’t sound workable. You would never get the rod into the bend area until you got the tube straight, if you got the tube straight. I would make/find a half round shoe/mandrel and work out the bend. Better yet maybe just change out the tube for new and straight. Good Luck, Dave.


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## ch2co (Jul 28, 2016)

Whatever you do, take pictures for us! I'd love to see how this works out.


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## countryguy (Jul 28, 2016)

ch2co said:


> Whatever you do, take pictures for us! I'd love to see how this works out.


...A video and pics is in the works with a write up for the CNC forum.     Very happy too.


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## countryguy (Jul 28, 2016)

I ran the propane torch on it and did get it both straightened out, plus new bend put in.   thanks for the help!!!  t'was easy! 

So the fit w/ the cradle and measurements from F360 to 3D was outstanding.  They seem to hold some decent tolerances.     But- Now I need to go back and figure out a way to make the tube fit....   Pretty close for a 1st print.    Giddy-up!  Will put up pics, and a meshed 3d Print vid in the CNC forums soon.   Under  "What I did on my summer vaction:  3d & fusion" .


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## countryguy (Aug 16, 2016)

I have posted the full Vid and some pics on the CNC forum of the overall F360 and new head project.  She's done.  
http://www.hobby-machinist.com/threads/s45-plasma-head-3d-print-for-cnc-diy-torch-holder.49625/



ch2co said:


> Whatever you do, take pictures for us! I'd love to see how this works out.


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