Hi All , I am looking for a cheap S-shaped metal arm , sme and other S- shaped arm tubes alone go for 40.00 to 80.00 on ebay . . . so I am looking for a cheaper source, does anyone have any Ideas? - I was thinking along the lines of a " schick " style of arm. One thought I had was aluminum arrow shafts... has anyone any expierance with trying to bend one without it folding ? - Thanks for any help, dean
Have a look at Nanook's project tone arm here: http://www.diyaudio.com/forums/analogue-source/173861-my-latest-iteration-nanooks-219-tonearm.html
It's a very cool arm, and he has been distributing them for the cost of postage to those willing to experiment. I have one and am just about to get started with mine. They are very easy to replicate in the event that there are no more available, and the reports are very positive.
I have not tried this myself, but have been thinking of trying something similar.
Have you tried putting a steel cable the same size as the inside of the tube in it before you bend? Use lots of grease.
Let me know if it works.
Hi Guys - Thanks for the Ideas, - Hi Kevin I will get in touch w- Nanook and give the 219arm a whirl.... - Hi nikongod, - Thanks for the steel cable Idea - It had also occurred to me to try fitting something inside the tube to help keep it's shape, but your cable idea is better then what I had thought of - - I will let you know how it works, I'm not sure what size of tube I need . . . I guess I need to buy a headshell so I can match the arrow tubing to it. - I will try ebay, if you have a another source for a cheap headshell or just the connectors for headshells let me know - thanks, dean
Tightly packed sand, with sealed ends will help, however it may very well depend on the alloy used, as some of the harder one's might crack. Heat plus sand?
aluminium arrow shafts...NOPE!
arrow shafts are usually made of very high strength, brittle hardened aluminium. In fact that is one of the toughest things to do when making any arms out of this these.
I even had purchased some "soft" brass, and using a tubing bender crimped it, so I guess I need to get thinner walled brass, or heat the brass while trying to bend it, then heat treat it. Another thought is using aluminium tubing that is not heat treated, and then heat treating it after the shape and all possible machining or drilling is done.
Rather than an "S" shaped arm, a straight arm has many advantages. An offset headshell is easier to make or have made, than using soft aluminium and then heat treating it.
Another method could be utilized as well: use arrow shafts, but get some thin walled tubing (perhaps steel brake lines?) and bend the desired angle. Heat treating a small piece of steel tubing is much easier than a long aluminium tube. Cut the tubing long enough on one end to allow it to be inserted into the arrow shaft, the use silver solder or JB weld to attach it.
arrow shafts are usually made of very high strength, brittle hardened aluminium. In fact that is one of the toughest things to do when making any arms out of this these.
I even had purchased some "soft" brass, and using a tubing bender crimped it, so I guess I need to get thinner walled brass, or heat the brass while trying to bend it, then heat treat it. Another thought is using aluminium tubing that is not heat treated, and then heat treating it after the shape and all possible machining or drilling is done.
Rather than an "S" shaped arm, a straight arm has many advantages. An offset headshell is easier to make or have made, than using soft aluminium and then heat treating it.
Another method could be utilized as well: use arrow shafts, but get some thin walled tubing (perhaps steel brake lines?) and bend the desired angle. Heat treating a small piece of steel tubing is much easier than a long aluminium tube. Cut the tubing long enough on one end to allow it to be inserted into the arrow shaft, the use silver solder or JB weld to attach it.
Hello halcon83
You might try to attach plumbing fittings to the ends of the tubing. Then pressurize the tubing with a grease gun. Then bend it. Of course the tubing has to be cut a little longer than final size.
Years ago I built a bending machine to bend 7/16" diameter 6061 aluminum tubing into a full 12" diameter circle. I had no problems with doing that because I'd discovered a neat trick, apparently developed by a company called "Tools for bending". It involved a bending wheel with special geometry. If you are truly interrested in that method, I'll make a drawing for you and post it.
Ralf
You might try to attach plumbing fittings to the ends of the tubing. Then pressurize the tubing with a grease gun. Then bend it. Of course the tubing has to be cut a little longer than final size.
Years ago I built a bending machine to bend 7/16" diameter 6061 aluminum tubing into a full 12" diameter circle. I had no problems with doing that because I'd discovered a neat trick, apparently developed by a company called "Tools for bending". It involved a bending wheel with special geometry. If you are truly interrested in that method, I'll make a drawing for you and post it.
Ralf
The idea of packing the subsequently sealed tube with sand or grease is to allow the tube to bend without kinking or having a reduced diameter in the bend. Building custom headers for cars usually involves using a special mandrel that withdraws while the bending wheel is advanced. This requires some precision machine work as the mandrel and bending wheel must be sychronized for a full diameter bend in the pipe.
Best Regards,
TerryO
here's something you might find useful.. ;-) Prepper Tip- Bending copper tubing with ICE! - YouTube
When be ding small diameter copper pipe, for still heat exchangers, u heat briefly to remove temper, put a short strong Spring on the OUTSIDE of the pipe and bend the spring. Only work the metal once or it hardens. I imagine the same process might work for the small s bend in an arm. The spring stops the tube kinking by supporting the tube wall
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