twisting aluminum problem 1

[aghil139]

hi all.
i have a small piece of 6061 aluminum with 6cm length. i want to twist it by 45 degree.
how can i do it.
this device is an antenna and will be used in 6-18GHz.
i want to know if i can heat this device and rotate it by 45 deg with linear step?
or some other ways to manufacture it.

 

[MikeHalloran]

It's as simple as gripping a 12cm+ length of extrusion between two pairs of jaws in a fixture, and rotating one pair of jaws with a long lever.
Then you cut off the ends and use the middle.
You have to semi-automate the process with mechanical stops and such to get consistency. You are still at the mercy of the material supplier for nonisotropic properties within the raw workpiece.
You don't really need to heat aluminum to form it, and there are good reasons not to. For one, it doesn't give you nice incandescent colors like steel; it just melts, or doesn't.

OR, you could CNC mill two halves to finished dimension and shape, and dip-braze them together. Because the most obvious parting surface is a helix, this requires some fancy milling, but with CNC machinery, it's just a matter of deciding how nice a finish you want, and adding enough time to produce it.

OR, you could make a pattern from plastic or wax, and investment cast the product in aluminum to net size, save for milling the ends flat and adding seal grooves, fastener holes, etc.


Mike Halloran
Pembroke Pines, FL, USA