4mm bend circle

[Simon Edwards 7Participant @simonedwards7]

Hello All.

I am looking for some helpful tips or guides on how to bend a miniature aluminium pipe in a circle that is 15mm across with a stem so it looks like a halo.

Its purpose is to be a cooling ring for a brass tip I intend to drill 1mm holes in the ring once its bend and use an air pump to push air through the pipe to the drilled holes.

I have tried bending it by hand but have been unsuccessful getting kinks and not a good circle.

I know I could use a brake pipe bender, but that will only get me 90 degs if I am right in thinking or not?

Any help is really appreciated.

[Simon Edwards 7Participant @simonedwards7]

How to bend a 4mm pipe into a circle 15mm

[not done it yetParticipant @notdoneityet]

15mm ID or OD? Dimensions of pipe – OD and ID? Complete ring or just a circular shape? Is the feed through the pipe or T’eed in?

Might get some response with more details.

Using copper instead of aluminium might be easier.

Edited By not done it yet on 19/07/2018 09:50:30

[pgk pgkParticipant @pgkpgk17461]

From the description it's a 4mm tube.likely the od to be bent almost 360 circular with a sharp 90deg into that circle.

I'd guess that's pretty challenging perhaps best attempted with the tube filled with one of the low temp alloys that melts below 100C. Still I'd guess a challenge at 15mm diameter and I'd wonder if it might be better to try and redesign so that the coolant circle is made from a grooved hollow disc with cap and upstand for plugging the feed-tube into.

pgk

[Michael GilliganParticipant @michaelgilligan61133]

Pending availability the additional details requested by ndiy [but aware that 4mm pipe was mentioned] … I would suggest bending the pipe into a helix, and then sawing one turn out of it. This is the way that jewellers make 'jump rings' and it is a simple matter to align the cut ends by twisting.

MichaelG.

[JasonBModerator @jasonb]

As you are more than likely to be using something like KS or one of the other hobby tubes then that is generally quite hard as supplied so best to anneal it first. Rub a bar of soap onto it then heat until the soap turns brown/black and allow to cool.

You can now fill as suggested by Michael and then bend around a suitably sized cylinder. Still not going to be easy but that will give you a good chance.

[Clive FosterParticipant @clivefoster55965]

Although it can be done freehand on a circular former a certain amount of skill and technique will be needed for a nice result. For right first time results its probably faster to go the long way round and make a mandrel with a helical groove in it to guide the bend. Twist flat after cutting as Michael G says. Groove maybe 2.5 to 3 mm deep. Massage it in with a shallow grooved roller is probably theoretical best way but a suitable piece of soft wood ought to do just fine. If you do go to the trouble of making a roller it will make a nice guide for the sharp bend.

Pipe will have to be filled.

I almost invariably find I need 2 or 3 practice runs to get decent results on this sort of freehand work. No 3 is OK, no 4 being right. YMMD.

Clive.

[vintagengineerParticipant @vintagengineer]

You could try filling it with water and freezing it then bend it.

[HOWARDTParticipant @howardt]

Why not machine it out of solid in two pieces. I let can just be tapped and ring groove can be complete circle. If you don't have a machine shop use a hole saw to create the groove. Nuts and bolts can hold the two parts together solder inlet pipe or tap a hole.

[Simon Edwards 7Participant @simonedwards7]

Posted by not done it yet on 19/07/2018 09:46:40:

15mm ID or OD? Dimensions of pipe – OD and ID? Complete ring or just a circular shape? Is the feed through the pipe or T’eed in?

Might get some response with more details.

Using copper instead of aluminium might be easier.

Edited By not done it yet on 19/07/2018 09:50:30

http://www.themakerhive.com/shop/ccdata/images/full3_6_45.jpg

This is what I want to make, the reason for doing it myself is the very very high postage costs from the USA, and even they agree with that part.

[Simon Edwards 7Participant @simonedwards7]

Thank you all for your help

[Michael GilliganParticipant @michaelgilligan61133]

http://www.themakerhive.com/shop/viewitem.php?productid=47

That should be very easy to make, Simon

… Selecting suitably soft tube will help a lot.

I have some salvaged from a gas cooker hob, but I think it's too large diameter.

MichaelG.

Edited By Michael Gilligan on 20/07/2018 22:49:10

[DalboyParticipant @dalboy]

Would caravan gas copper tubing be any better for bending or even suitable for the job. I may have some small diameter stuff but will have to check in the morning

[Simon Edwards 7Participant @simonedwards7]

It has to be 4mm or better still 3mm OD any larger and it will sit proud of the nozzle.

https://www.thingiverse.com/thing:2638144

that shows one fitted as you can see it has to be that small in the OD.

[Michael GilliganParticipant @michaelgilligan61133]

There is a lot of information on this site: **LINK**

http://www.drawntube.com/products.htm

MichaelG.

.

P.S. … Check the two lines at the bottom of this list:

http://www.ksmetals.com/23.html

Edited By Michael Gilligan on 21/07/2018 05:34:21

[not done it yetParticipant @notdoneityet]

It doesn’t look like 4mm OD tube to me if those holes are 1mm in diameter.. It looks like there is more space,without fouling anything, from that pic. What is the real postage cost for one, or several, of these things from the US? BeeAmaker is likely a better person to ask. He seems to make out it is easy. It doesn’t cool brass? Seems like it cools hot plastic. Area of holes is 9/4Pi. If tube has a wall thickness of only 0.5mm the cross section will be the same as the 9 holes, so I doubt the air flow from the holes will be uniform. Any thicker wall and flow will be worse.

Wrap it around a wyteboard marker pen or similar mandrel. I don’t see any particular problem except for the design parameters. Hydraulic brake pipe would be my choice. Fill with low melting point solder, bend and melt out the solder. Check out the u-toob videos that give other clues for making the ring. Loads of options and it doesn’t look like it needs any particular precision.

[JasonBModerator @jasonb]

Says it's 3/32" (2.4mm) pipe so being from US the holes will probably be 1/32"

[Michael GilliganParticipant @michaelgilligan61133]

Hopefully this link will still work, now that I've removed umpteen [tracking?] characters:

**LINK**

https://www.ebay.co.uk/i/253596166649

MichaelG.

[Simon Edwards 7Participant @simonedwards7]

Posted by Michael Gilligan on 21/07/2018 07:45:11:

Hopefully this link will still work, now that I've removed umpteen [tracking?] characters:

**LINK**

https://www.ebay.co.uk/i/253596166649

MichaelG.

Thank you

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