.

… and yet : **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=167860

MichaelG.

I think the incentive for making your own tool is that the distance between bends can be reduced when you make your own tooling. Tools such as the Dubro have a fixed minimum distance between bends which may be too restrictive for some applications. Adding some sort of joint between bends to allow a cut and join operation for reduced distance between bends may be unacceptable at this size, too easy to block the bore, have a weak point or have an unacceptable bulge if a sleeve is used as a union.

Martin C

I also needed to make some tight bends close together on 5/32 tube. I bought the Dubro and its former wheel groove diameter is 11mm, so 5.5 mm +5/64" cl radius. The disadvantages of the Dubro are that it needs 12mm or so of straight tube before and after the bend and its plastic body means that it will only bend annealed tube.

I then wondered how I could make the simplest possible tool and came up with this:

Took half and hour to make and although restricted to 90 degree bends, it works a treat on un-annealed tube. Groove diameter of the former is 7.5mm. Make sure the groove is deeper than half the diameter of the tube so the tube is positively prevented from going oval during bending and the groove in the clamping block needs to be shallow enough that the tube is solidly clamped when in the vice.

Funnily enough we discussed tube bending on yesterday's St Albans club zoom. Woods Metal was sugested as an aid and first put olive oil in pipe to stop it sticking.

Posted by geoff walker 1 on 29/10/2020 13:09:27:

No prizes for guessing what it is?

geoff

Your wife is not going to be happy with the sink taking 6 hours to drain through such a small u-bend

Oh yes Bazyle!

My wife does complain a lot.

Only yesterday the handle came of a pan lid.

I was charged with fixing it right away, which I did.

Of course she complained, not good enough she said.

No pleasing some

Geoff

Steve there is a thread on here for pipe bender I have made.

Search for Derek browns pipe bender MEW297 and you will find it.

There are numerous drawings in the thread but a read of the article would help if you intend to make it.

Geoff

Geoff would that be issue 297 ?

H

Double post

Edited By geoff walker 1 on 29/10/2020 18:31:19

GW1 – Your wife may not appreciate your efforts but, I do! As de facto 'cook' for self and partner, my constantly less effective grip makes 'normal' round centrally placed knobs increasingly difficult to grasp. Your 'repair' as a properly incorporated design would make life much easier!

Patent Office, anyone?

rgds

Bill

What I love about engineering in general is that there is always more than one way of doing things so here a a couple of alternatives –

Don't bother bending the pipe. Keep it straight and use elbows and tee's when you want to turn a corner. These are available as castings or ready made items. Or you could machine/fabricate your own from bar stock.

When using thin walled tube (particularly brass) it has a tendency to collapse if bent through a tight radius. Anneal the pipe, let it cool, then pack it with something that will bend but won't let the pipe collapse. One approach is to plug one end of the pipe, fill it with table salt and plug the other end. The advantage with this method is the salt is easy to remove once the bending is done. However, depending on the internal diameter of the pipe or tube this procedure gets progressively more fiddly as the diameter gets smaller.

For (really) small diameter tube insert a styrene rod that is a close sliding fit. Bend the tube into whatever shape takes your fancy. Remove the styrene rod by burning it out with a blowtorch.