Pipe Bender WIN!

[BenM78]

Further to this thread here - http://www.woodworkforums.com/f65/pipe-bending-fail-120570/

I came across a post on another forum that showed the results of heating the die, hammering it a millimetre or so smaller and then bending tube. There is also a thread on this forum http://www.woodworkforums.com/f160/hydraulic-pipe-bender-137313/ showing the same process.

So I gots me a roaring fire going this arvo, with a bit of pipe hooked up to my vacuum on backwards to ensure plenty of heat and brought my 20NB die up to a dull red and proceeded to git it a thorough belting (forging I think they call it...)

First test bend when I got the bender...

http://www.woodworkforums.com/attachments/f65/141320d1278715768-pipe-bending-fail-pipebendfail.jpg

Test bend after 'fixing' the die, this is the exact same piece of 20NB pipe BTW.

http://farm7.static.flickr.com/6127/5942282426_a537b28881.jpg

The die is a little tight and took a fair bit of persuading to release from the pipe, will file the high points down and see how it goes.

Suffice to say, it seems the chinese dies can be altered to achieve the outcomes expected of them if you are prepared to put a bit of time into fixing them... I really need a proper forge though - an open fire on the ground took a LONG time to get hot enough to heat cast iron!

Ben

[pjt]

Had the exact same problem bending tube, I fixed it by bending a piece of sheet metal and placing this in the die then proceeding to bend the tube effectively closing the die just like you have done :2tsup:

Pete

[festy_]

The difference a mm makes is amazing, isn't it?

pjt's post about lining with sheet metal reminded me of something else - if you want to bend RHS with your pipe dies, first get a piece of ~5mm solid round bar and bend that in the die you're going to use, so it conforms to the bottom of the die.
Then, stick the RHS in on top of it and bend away. The round bar pushes up the inner wall of the bend radius a little, stopping it from kinking.

I've made a few roof racks and things out of 20mm RHS this way - you just have to make sure everything is lined up properly before bending, because the die and rollers are designed for round pipe.
It works well enough and produces pretty consistent and neat bends.

[pjt]

The difference a mm makes is amazing, isn't it?

pjt's post about lining with sheet metal reminded me of something else - if you want to bend RHS with your pipe dies, first get a piece of ~5mm solid round bar and bend that in the die you're going to use, so it conforms to the bottom of the die.
Then, stick the RHS in on top of it and bend away. The round bar pushes up the inner wall of the bend radius a little, stopping it from kinking.

I've made a few roof racks and things out of 20mm RHS this way - you just have to make sure everything is lined up properly before bending, because the die and rollers are designed for round pipe.
It works well enough and produces pretty consistent and neat bends.

That's a handy little trick:2tsup:

Pete