drive shafts

[mudit87]

is there any way to make solid mild steel drive shafts hollow and can there any other material that can be used for hollow drive shafts for same torque constraints

[mudit87]

is there any way to make solid mild steel drive shafts hollow and can there any other material that can be used for hollow drive shafts for same torque constraints

[Conor]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by mudit87:
is there any way to make solid mild steel drive shafts hollow and can there any other material that can be used for hollow drive shafts for same torque constraints </div></BLOCKQUOTE>

First off, mild steel is probably a big no-no. I would suggest using 4340 as does Carroll Smith. We did a bunch of worst case calculations for our shafts and found that spending the few extra dollars was well worth the improvement in strength. It may have been our supplier, but the 4340 stock we got was only 10 dollars more than 4130. To lighten your axles, you can make them hollow by gun drilling them. If you're a newer team and don't know of anyone who gun drills, I'd probably just run solid shafts and save yourself some time. If you do decide to gun drill, make sure you re-work your calculations for the shear strength of a hollow tube with given wall thickness instead of a solid cross sectional area.

[mtg]

Yes, use a hyperbolic drill bit. I machined some from solid bar stock, gundrilled them with a hyperbolic bit (the bit was about half as long as the shafts) and the two holes met in the middle within about 0.020" or less.

This wasn't too long after taking a class where the teacher was saying hole making as one of the fastest machining processes. I felt cheated. Those holes took FOREVER to drill.