Robert Swinney was right on the mark.
I tilted the tool to approxmately the thread angle and saw an
immediate improvement.

one other suggestion locally was that a tool out of 1/8th square HSS
was never going to be rigid enough even when supported by another
regular tool.
I'll grind a new one out of some parting off tooling.

if you want to see this item of torture there is an article on
building nano at www.modelenginenews.org/nano/index.html
the model isnt mine.

thanks Robert. I knew it had to be something really simple that I was
missing.
Stealth Pilot