Wow......been off the thread for a while as the site did not email me on current posts as they occurred.
One thing I will say.......and that is purely my personal and biased opinion, and that is....if you delve into the world of complication and exotic materials with even more exotic methods of applying them for a less than predictable outcome, you are living in your own world of exoticism and for the ordinary person seeking an ordinary and achievable method for whatever purpose, which in this case is a viable and achievable method to have a backlashless rotary table....whatever....... the plot is definitely getting lost in translation.
The DIY harmonic drive manufacture is tantamount to going to the Moon in a garbage bin propelled by the power of a bundle of fire crackers when placed in the hands of the average or above average machinist to make with the machinery generally available at that level, and by that I mean a lathe and a mill without any grinding equipment you could shake a stick at.....the outcome is definitely not predictable.
If the outcome is not predictable, then the method is hit and miss at best.
I think I will stay with the spring loaded worm and worm wheel method as that to my mind seems to be the ideal and achievable simple solution that will produce results that are predictable.
How can that be so categorically stated.........well a worm wheel can be very accurately produced and the worn too and applying one against the other produces very accurate results as all dividing heads are witness to, despite the fact that all dividing heads and rotary table have backlash to some degree, and 4th axes or rotary tables are just brothers of the same relationship.......spring loading the worm would I think solve the backlash problem without breaking the bank.
It certainly is not a hit and miss solution with a dubious outcome solution that I proposed as some have indicated.......probably because the simplicity is not exotic enough.
This is like digging a grave with a gold plated shovel for a deceased person of high office, as opposed to a common spade you can buy at the local hardware store........it may not fit the occasion but the outcome is the same.
My hat's off to those that produce the harmonic drive and get it to work, even if not with 100% results, but for the record, it will not be something that will be common practice.
Ian.