Vmax, I recall you mentioning that before. I have installed needle roller thrust bearings on each end, those are neccessary for operating as a spindle and they actually peeked out past the surface in one spot . You can see the oil leaking out at that spot in one of the photos. If not for cutting the ends for the thrust washers, I could do as you suggest.
A new servo drive (Viper) and a little more voltage should get the 4th axis to a max of 2,500 RPM with a 2:1 ratio. Sustaining that speed for hours on end would cause trouble with the setup you are suggesting. At a minimum, it would consume a lot of power and I don't have so much I can give it away to a plain bearing or to a non bearing thrust. Used as an indexer or at low speeds, I agree with your assessment.
A full ball bearing head with sealed bearings is the way to go for a reliable zero play spindle on a budget, methinks. I'm going to 'ghetto' it a little with just some quality SKF 'Precision Plus' bearings and not angular thrust or high precision. No point with the current machine that flexes all over the place anyway . . .
Hood, how do I post something specifically to a Mach3 group on Youtube? I have Mach3 as a keyword, but that's all I know to do. Not a big 'tuber. Still dinking around trying to get the best HD quality too.