My objective in posting was to highlight the fact that having had a problem, Gary at Eccentric Engineering helped me to solve it.
My "alternative solution" was to grind the toolbit so that the radiused corner was no longer the cutting edge, i e a true diamond tool. This cured the problem with the original set up, but meant that I was effectively cutting a shallow 454 tpi thread. of unusual form. (If you think about it, all feeds produce a helical cut; regular if using power feed, more irregular if hand fed)
It is easy to complain about a supplier who provides poor service or back up; but those who support their product and the end user, often "going the extra mile", do deserve praise.
Mike T
Can you please tell who said that e sarcasm is the lowest form of wit?
I thought that the Forum is for members to help each other
Howard