I've spent the last three weeks knocking together a toolpost grinder. It would have been quicker but I had a nasty cold in the week before last and that slowed me down somewhat. The grinder is loosely based on some of the ideas from Prof. Chaddock, but only enough to give me ideas on what not to do when I get to building the Quorn.
I can confirm that using a home made toolpost grinder leaves the lathe in cleaner and better adjusted condition than before. The three hours to strip down and clean the saddle, cross slide, top slide etc are a bit of a nuisance though. That's even after using large amounts of oil soaked rags to catch the grot.
The surface finish I'm getting is significantly better on hardened steel than the turned finish from before the steel was hardened. It's still nowhere near good enough. I can just about see my face in it, but it makes me look short fat and ugly. I had found that the vibration from the current single phase, not resiliently mounted, motor and belts was causing significant marking of the workpiece. This was fixed by turning the mandrel using a handle. The armstrong motor causes much less vibration than the (Hoover) electric one. There is still a bit of an out of balance in the grinding wheel mounting that is causing a mottled finish on the work piece, even after dressing the wheel.
I'm experimenting with a, tuned, mechanical balance indicator. I've also got a dual channel accelerometer and once-per-rev signal detector on order to balance the setup properly. The electronic bits will either get used with a dual channel scope that I've got in the loft or, if that doesn't work any more, I'll borrow an HP signal analyzer from work.
Tomorrow I'm going to go back to manufacturing the shafts for the Hardinge apron gearbox. I'll make a couple more dummy pieces to use when sorting the grinder out and aligning the lathe tailstock. Then harden the lot and have a week or so of grinding needle roller journals to size.
Mark Rand RTFM