@Darren &
@Dabbler. No scales on your carriage eh! Too funny!
I have a nice scale on my carriage but I don't remember ever using it! I use the scales on my compound, cross-slide and tailstock all the time. But never the carriage.
Those few times I needed it, I used my compound set at 90 instead.
What's really crazy about that is that I honestly can't put my finger on why that is...... Very Strange!
And from the other side, I cannot fathom putting a DRO on either the compound or the tailstock, as neither of those were ever used for anything that amounted to precision. The only installs that sorta seemed to make sense to me, (although they also seemed not worth the price or complications, even in the real world pricing of high end commercial DRO's) integrated a qualified angle sensor and the compound slide together, and did a lot of math, so as to keep track of the tool position that may have been saved in memory. Since I have yet to work anywhere that I could reliably set up just one main set of tools, that was never an option for me.
I made about my body mass equivalent in straight, tapered, and top-hat style bushings for refurbishing f-18 flight controls, structural elements, and landing gear, as well as a LOT of other parts, and cannot really picture a part that I would have been at any advantage with, having either the compound, or tailstock, instrumented.
Holes were drilled undersize and bored or bored then reamed, to ensure size and concentricity. The compound rarely got used unless it was strictly to put a bevel of a particular angle on a series of parts, or when threading, in which case the re-settable dial would be set with the desired infeed, and depending on your tastes, you could work either to, or away from, your zero point, with the cross slide simply used for pulling the tool, and resetting to Zero, on each pass.
So, color me curious... How do you get use out of those scales? You do most of your work with the carriage locked and spend all you time dicking about with the cross slide and compound? Seems kinda arse backwards from my perspective, if so.
Given that almost EVERY lathe I have ever seen out in the wild, had only a cross slide scale, and full length of the bed scale on the carriage, it seems that it IS essentially how most folks work.