: Though a little off topic, here is a challenging project for you wood
: turners. We have been working on this all week and after much head
: scratching I thought you might like to see our solution.

: The picture shows an 85 ft carbon fiber mast we built for a customer.
: Normally the bearing that supports these masts fits inside the mast or is
: epoxied on to the mast so the outside dimensions don't have to have high
: tolerances. However the spec for the foot of this mast has to be within
: 1/1000 of an inch because it is designed come out to be lowered under
: bridges. You can imagine that after 30-40 layers of CF braiding the
: outside is not a perfect circle.

: To get the supports ground to spec we built an 85 ft lathe and hooked up a
: router to mill the mast as it spins. Over the 85ft span the mast barely
: sags an 1/8th of an inch but is not exactly straight. Building a frame
: that would hold the mast and getting it centered on the chuck so that the
: whole thing could spin correctly was a bitch. Tomorrow we will grind the
: three rings of fiberglass wrapped around the CF that will be the bearing
: surfaces.

: Hope you don't mind this off topic stuff but I thought you guys mightlike to
: see this.

: Regards,

: Jack

Hi Jack

Interesting project.

I can't tell, but is there a tail piece involved or did you merely support it in the center with some sort of rollers??
If you had only center or "past-center" supports would you even need a tail-piece..?? Seems you would be able to rid yourself of even that 1/8" variance.

I envy you and your fellow workers for the type of problems you have..

Would be interesting to see up-close and personal.. Thanks for the Photo Tour.

Rehd