| |
03-17-2010, 10:18 AM
| #1 |
| owner, Holmes Hobbies LLC   Join Date: Nov 2004 Location: Volt up! Gear down!
Posts: 20,290
|  Thin wall tube bending
I am having some issues bending tubes without kinks. Not exactly R/C scale, but the problem would apply to thin tubes all the same. I have a 3" radius die for 7/8" tubing. It can go down to .058" wall, but I need to bend some .035" wall. Of course I tried and I got creases in it, and beyond about 40* the tube kinks in half. What can I do to prevent this? I have heard of packing sand in the tube. I am using a JD2 model 32 bender. I called and asked about a custom die for the thinwall stuff, but the tech support said they couldn't do that. |
|  |
| Sponsored Links | |
| | |
|
03-17-2010, 10:47 AM
| #2 |
| Quarry Creeper Join Date: Oct 2008 Location: Marysville
Posts: 452
|
Could you run a piece of cable inside the tube to keep it from crushing or kinking?
|
|
| |
|
03-17-2010, 11:40 AM
| #3 | |
| Rock Crawler Join Date: Nov 2006 Location: Holland
Posts: 673
| Quote:
That is the solution.  Make sure the sand is clean and dry to prevent a steam and/or gas explosion. Get a piece of hardwood for plugs and make sure the plugs fit well. Heat up the tube before bending so the metal can stretch and crimp. Bend slowly. | |
|
| |
|
03-17-2010, 11:10 PM
| #4 |
| Quarry Creeper Join Date: Jul 2008 Location: lansing
Posts: 309
|
i dont think tis will work for you as your tube is probably too long. but you could apply it is you do something in smaller scale. soapy water. plug one end of the tube and fill it with soapy water, not all the way though(water expanding) then freeze it. the soap in the water will cause the "ice" to be flexible. and you can bend it with no kinks. they use this method when making brass instruments. |
|
| |
|
03-19-2010, 07:46 AM
| #5 |
| Quarry Creeper Join Date: Feb 2010 Location: Knee deep in a creek with a fish on the line
Posts: 456
| sand is the answer
I had a roommate in college that worked with aluminum tubing all the time, and sand is the best bet. He never had any problems after he found that trick.
|
|
| |
|
03-19-2010, 07:58 AM
| #6 |
| RCC Addict Join Date: Feb 2008 Location: Winnipeg
Posts: 1,296
|
another vote for sand! Had to d t a few times bending some small stuff and worked every time!
|
|
| |
|
03-19-2010, 09:18 AM
| #7 |
| I wanna be Dave Join Date: Nov 2009 Location: Chico now
Posts: 2,384
|
Maybe use a tightly wrapped spring around the outside of the tube. I've seen them at ACE hardware in the plumbing section.
|
|
| |
|
03-19-2010, 11:28 AM
| #8 |
| Quarry Creeper   Join Date: Feb 2010 Location: Duluth
Posts: 388
|
sand in the tube works great, instead of wood plugs I use corks
|
|
| |
|
03-20-2010, 09:03 AM
| #9 |
| Newbie Join Date: Feb 2006 Location: Ottawa Kansas
Posts: 32
|
Other than sand and bending springs which do an OK job sometimes, the only thing that I have used on very thin wall tube is fixturing alloy. For those who are unfamilar with it, fixturing alloy is a low temp metal that looks like lead. It is used in machine shops sometimes to hold irregular shapes in position for machine work. I have used it to machine features in parts that have very thin walls that require extra support. It is available in different melting temps, the stuff I have melts in boiling water and can be reused again and again. You just melt it some in boiling water, pour into your tube, let it cool and then bend. The nice thing is that since it melts at such a low temp your part will not discolor with the heat of pouring in into the tube and melting it back out. Unlike sand it will not shift around during bending and I have found it much easier to use. You can find it in 1 pound sticks from mscdirect.com. Not really cheap or fast but it works. Fastball |
|
| |
 |
| |
Linear Mode
