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Tools of the Trade If you have a question about what tools we use in creating our trucks here. Also discuss any tool experiences you have, the good the bad and the ugly! Hand tools to all out CNC machines!

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Old 01-29-2012, 04:08 PM
Crazy Drew Crazy Drew is offline
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Default Problems bending tubing

After a 6 month hiatus on my projects to spend time on my other hobbies I've decided to pick up where I left off on my CC-01.

I am attempting to build a roll cage for it (non structural) out of 5/32 brass tubing using a du-bro bender.

Just about everything I attempt collapses the wall of the tubing, making it ugly and making me worry about it getting destroyed when I drive this.

I have tried:

Lubing the tubing before bending
Freezing soap inside to support the wall
Flour in the tube, although its too small to pack thoroughly

Since it really doesn't play any role in strength I'd like to avoid using solid brass rod as it'll turn this into a top heavy pig that's not fun to drive.

So far, the only thing I have done that works is to anneal the tube, by heating it until it changes colors and allowing to cool back to room temperature. This however makes the whole tube so soft that if you look at it funny it bends.

Any suggestions welcome. If I can't sort this out I might try steel tube. But it'll be so small I'll be miserable tig welding it.

I'm using this style bender with k&s 5/32 x .014" . The bender came with a few small pieces of brass that bent great, although it was much thicker wall.

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Old 01-29-2012, 04:20 PM
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scale4x4 scale4x4 is offline
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you could try heating the tube as your bending, or filling it with table salt, or sand, or fill the tube with water and freezing it.
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Old 01-30-2012, 04:11 AM
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2redrovers 2redrovers is offline
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Did some reading and hopefully I can offer some help. From my understanding, brass when heated/annealed isn't affected by speed of cooling in the way steel is. In other words you can heat brass and quench it and it remains soft (a generalised statement which does not account for reactions of all types of brass alloys). Brass work hardens. Bend it, beat it, hammer it and it stiffens up.

Possible tips for working tubes.. anneal tube, bend to shapes required, then gently hammer/squeeze tube till slightly oval. This should provide enough working to re-harden the brass.

When heating the brass try using a small butane torch that can pinpoint heat just the section to be bent. Keep it short and only just enough to do the job. That way when you create the bend it should re-harden that section while the rest of the tube is hopefully still near normal.

A strange one that may help in some circumstances.. once the piece has been bent/formed and appears to remain too soft, try tinning the inside of the tube with solder. Feed some solder wire into the tube heat until liquid and allow excess to drain out. The thin coating left behind will solidify as it cools and add some stiffness without making the end result as heavy as solid brass.

Good luck and hopefully this has been usefull info.
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Old 01-30-2012, 02:47 PM
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79BlackPearl 79BlackPearl is offline
just gaining experience after I need it....
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These work like a champ for me.
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