Homebrew PCBs

On Sat, 12 Mar 2005 13:57:27 -0000, Leon Heller  
<leon.heller@...> wrote:

>
> Titanium is *very* stiff, more like steel than Al. It's difficult to
> machine. Why not use a plastic shaft, something like Delrin should be OK?
> Leon
> --
> Leon Heller, G1HSM
> http://www.geocities.com/leon_heller


Oh well, that would need a larger diameter.
I guess it would be ok if i go with the bigger diameter pipe.

But then, i don't need to machine it at all (maybe saw to length and  
polish as well as smooth the bottom end that rides in the bearing, so i  
might as well use titanium if i get it surplus.


Which diameter would a delrin shaft need to be if we say the tube is 50mm  
dia and 20cm long? the shaft is supportint the tube via the two endplates.  
How would i make the bearing with a delrin shaft? Does it run well in ptfe?


I also would have a carbon fiber tube from model building with 8mm dia for  
a shaft that could easily take the load, but i don't know how i would make  
the bearing if i use that. It is carbon fiber in some resin, probably  
epoxy, wall thickness is about a mm.

ST