[Zetopan]

So I could get the M pulley for my Series 2 and 3 machines to get more rpm?

It's not that simple. The existing PCNC1100 spindle bearings are rated for a specific maximum RPM and they have a specific preload. Simply increasing the RPM runs the risk of shortening the spindle bearing life due to excessive heat generation. As a single sample point, my late Series 1 PCNC1100 originally came with a simpler VFD that was prone to runaway on occasion. (Yes I know that there were numerous tweaks available but that only reduced the frequency of occurrence.) When the VFD ran away (lost speed control) the spindle would race up to near 8,000 RPM and the heat buildup in the spindle nose was quite rapid. As a result I always quickly stopped the spindle and restarted it to regain control. The heat buildup was so rapid that holding your hand on the spindle nose was sufficient to detect it. So for those spindle bearings the bearing preload would have to be reduced and/or the bearings might need to be replaced with some rated for a higher RPM.