Tube bender from scratch. plenty of pics.

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El-Kablooey
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Tube bender from scratch. plenty of pics.

Post by El-Kablooey » Mon Apr 14, 2008 5:00 am

I thought this project was worth sharing. I found some plans for a JD2 type tube bender and decided to go at it. The bender is easy, and the parts are being cut for me on the laser at work. I was originally just going to buy the dies I need, at $250 each. My dad convinced me to try casting them. I've had all his old sandcasting gear in my shop for a few years now and never even used it. I figured I had nothing to lose, and wanted to learn sandcasting anyway.

I started out with nothing but some plywood and bondo. I cut the plywood to the correct radius' and thicknesses, glued the pieces together, and made a bondo fillet around the circumference to get the correct radius for 1 1/2" tube. I made the pattern 1/2 of the die, to be cast in two pieces and bolted together. I have gotten as far as casting the two pieces. I still have to cast the follow bar also.

This has been alot of fun, really interesting. It's turning out better than I expected so far. I think it may actually bend tubing when finished! :)
If it doesn't hold up, I've still had fun and learned alot.

Here's some pics. Crap, the pics are in reverse order...
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Here's the first piece I cast, before cleanup.
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This is the second half, it came out a little nicer.
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Here they are together.
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larry cottrill
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Post by larry cottrill » Mon Apr 14, 2008 11:52 am

Beautiful -- I love seeing people try stuff like this! There's a unique satisfaction to making your own tools and then using them to do things you've always wanted to do.

Yes, when you upload a series of photos you have to plan the order, then upload them back to front. It's always been that way on the new forums.

Good luck with your bender. Be careful using it -- it's easy to get hurt bending tubing. If you're bending near an end, you have to pay careful attention to slippage. It's better to bend with some straight waste left to be cut off as a final step.

L Cottrill

Mike Everman
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Post by Mike Everman » Tue Apr 15, 2008 1:40 pm

It's not too much more effort to make it a mandrel bender.. Looking good so far!
Mike
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PyroJoe
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Post by PyroJoe » Sun Apr 20, 2008 3:33 am

When bending the thin walled pipe it may be useful to pack it with sand. Hammer only about 8 inches at a time, then add more, pack that 8 inches, etc. Use a healthy size hammer, above a two pound. Not sure what water moisture content most sands compact best at.

I use the old break clean test. make a ball of sand in your fist, squeeze it hard. break the ball in two, if it breaks clean it's good. if it crumbles it needs more attention.

Otherwise, when bending some thin pipes like the one I worked today wrinkle like a dang soda can.

A cheap and easy sand is clean "play sand" sifted through a door type screen. As I recall, I added flour to the mix, had a pleasing smell when used for casting, rammed up nicely. It actually molded better slightly damp, If it was dry the metal would pattern each grain of sand. With that little bit of moisture it would set before having a chance to settle into the grains.

Joe

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