Author Topic: Straightening copper tube  (Read 2358 times)

Offline Robert Hornby

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Straightening copper tube
« on: September 24, 2017, 02:47:53 AM »
All my previous orders "On Line" of 3/16" OD copper tube have arrived in straight pieces 12" long. However my last lot came in a coil. The good news is that the length is 900mm, meaning I wont have to join the lengths. The bad news is the pipe will not be nice and straight. I remember from somewhere long ago that with series of form rollers the tube can be straightened. What I don't remember is how many rollers and their alignment.  :headscratch:



Help please.
Robert

Age and treachery will always overcome youth and skill

Offline John Hill

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Re: Straightening copper tube
« Reply #1 on: September 24, 2017, 05:23:01 AM »
I find the easiest method of straightening copper tub is to straighten by hand being careful not to put sharp 'kinks' in the pipe.

Roll the pipe between two planks.  Avoid the temptation to roll the tube so fast that the ends flail around and put more kinks in, or worse.

Offline bent

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Re: Straightening copper tube
« Reply #2 on: September 24, 2017, 05:57:43 AM »

Offline Stuart

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Re: Straightening copper tube
« Reply #3 on: September 24, 2017, 06:48:22 AM »
It simple
Cut off a length roughly get it straight

Clamp on end in your vice , vice grips on the other end pull gently unit itís nealy straight then just lean back on it it will give about a inch , you should have a perfectly straight tube
My aim is for a accurate part with a good finish

Offline Bluechip

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Re: Straightening copper tube
« Reply #4 on: September 24, 2017, 07:16:03 AM »
All my previous orders "On Line" of 3/16" OD copper tube have arrived in straight pieces 12" long. However my last lot came in a coil. The good news is that the length is 900mm, meaning I wont have to join the lengths. The bad news is the pipe will not be nice and straight. I remember from somewhere long ago that with series of form rollers the tube can be straightened. What I don't remember is how many rollers and their alignment.  :headscratch:



Help please.
Robert

It's possible you are referring to a 'Pyro Straightener' used on mineral insulated cable.

Pics. exist on t'net showing the general arrangement if you want to make one.

First few pics. on here:  ( What relevance the rest are is anyone's guess .... :Doh:  )

https://www.bing.com/images/search?q=pyro%20straightening%20tool&qs=n&form=QBIR&sp=-1&pq=pyro%20straightening%20tool&sc=1-23&sk=&cvid=30F2D2A58C62490F8A9C22DAEC744A4E

Although I don't think it'll be much good on a 900mm length.  :thinking:


Dave
« Last Edit: September 24, 2017, 07:21:01 AM by Bluechip »

Online MJM460

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Re: Straightening copper tube
« Reply #5 on: September 24, 2017, 08:20:57 AM »
Hi John Hill,

I have sent you a personal message

MJM460
The more I learn, the more I find that I still have to learn!

Online MJM460

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Re: Straightening copper tube
« Reply #6 on: September 24, 2017, 08:30:18 AM »
Hi Robert,

I am not sure where you order your tube from, I purchase it from George Whites in Melbourne, which is located not far from home.

I have found one good thing to remember is that itubing actually comes in 3 metre lengths, whether straight or coiled.  Coiled may even be in 6 metre lengths. Obviously straight is not very practical for shipping.  Coiled is soft annealed while straight is hardened sometime referred to as half hard I believe.  But more importantly, the cost per metre of buying the full length is nearly half the cost per metre of shorter lengths, even when they are already off cuts on the shelf.  If you can decide your normal size requirements and spring the initial outlay, it definitely pays off over time, so worth investigating.  You also end up with less in the form of short off cuts when you cut each piece as it is needed from a longer length.

MJM460
The more I learn, the more I find that I still have to learn!

Offline Ian S C

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Re: Straightening copper tube
« Reply #7 on: September 24, 2017, 10:01:40 AM »
Just had a look on Google, saw a simple gadget, it consists of five rollers in 2 staggered rows, 3 in one row, 2 in the other. Each roller has a groove to take the tube. The tube was run through a few times, I think the width of the gap between the rollers was adjustable.
Ian S C

Offline Johno

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Re: Straightening copper tube
« Reply #8 on: September 24, 2017, 11:51:56 AM »
Like others have said, once you get it fairly straight by hand & eye, roll between two flat boards. The length that you require will be the limiting factor.

Offline Robert Hornby

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Re: Straightening copper tube
« Reply #9 on: September 24, 2017, 11:20:27 PM »
Thank you all very much gentlemen, I have lots of info now and will be able to achieve a straight length of tube. :cheers:
Robert
Age and treachery will always overcome youth and skill

Offline bent

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Re: Straightening copper tube
« Reply #10 on: September 25, 2017, 02:37:09 AM »
Step 1.  Roll tube between two planks.  Tube is straight but cross section is now oval.
Step 2.  Take another length of tube, straighten with multi-roller devices.  Tube is now straighter, with lots of little kinks in it.
Step 3.  Have a lager.
Step 4.  Go on amazon and order some new, straight tube... :Lol:

Seriously, good luck.  Let us know how it works out, and which methods worked best.

Offline paul gough

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Re: Straightening copper tube
« Reply #11 on: September 25, 2017, 08:22:11 AM »
Have a look on the back cover of the latest 'Australian Model Engineer' magazine for a photo of the 'KWIX' type supplied by ejwinter.com.au. Sizes stocked !/8, 3/16, 1/4 & 5/16, others available. Regards Paul Gough.

Offline Ian S C

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Re: Straightening copper tube
« Reply #12 on: September 25, 2017, 10:28:52 AM »
I like the look of the Klix tube straightener with it's 16 rollers, they are available in metric and imperial sizes. 
Ian S C

Offline steam guy willy

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Re: Straightening copper tube
« Reply #13 on: September 25, 2017, 01:13:27 PM »
Bending it strait  or straitening its bend ??  that is the question !!!!!

Offline Steamer5

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Re: Straightening copper tube
« Reply #14 on: September 25, 2017, 01:48:45 PM »
Willy,

It sounds like you are going straight round the bend!!  :stickpoke: :Jester:

Here's a link to the tube straightener that Ian mentioned.....


Cheers Kerrin
Get excited and make something!