I have a Tom Senior light vertical milling machine. The E type also sits on a round shaft. I have spent ages attempting to get the head exactly 90' to the table. When fly cutting it still tends to back cut when cutting in one direction. I cannot afford the twin type DTI set up just to correct this very minor error.

Jason

That is impressive. I don't think I've ever had my X3 cutting that well. I've got one of those fancy tramming jobers, had a go at the ARC quill setup instruction more than once, replaced all the quill bearings and have the jibs as tight as they can practicably be. I must have another go.

Pete

I've got the chester super-lux mill. Tramming that is a pita with three holding bolts and every time you tighten one the tram moves. It makes no difference whether one tries to go around them bit by bit or get two just tight enough to still move the head before doggng down the last then giving the first two a bit more etc. I've had it to that type of pattern with overlapping front and rear flycutter arcs but inevitably it moves after a few months and another hour or two of messing about to dial out the last fractions. In fact one has to assess the degree of 'out of tram' before tightening down to get it right when tightened. It is what it is.

Reality for me is that I don't usually have a need to work to tolerances where that matters and very slightly out of tram can give a mirror finish on ally with a flycutter. A heavier cut on steel will deflect the forward cutter arc more than the rear unless one builds a more rigid flycutter. My best cosmetic results on steel are with a solid bar-mounted round carbide tip.