I crashed my machine last week, so had to re-tram the head tilt. Yesterday I needed to do some face-milling. This machine has always had a small amount of Y axis head "nod" that I've never bothered to tram out (it would require shimming to correct). The X axis tram is now nearly perfect - a few tenths over about 11". So, I thought, if I do the face-milling parallel to the Y axis, I should get a nice, smooth surface, if very slightly tilted in Y. But, to my surprise, I ended up with small, but perceptible, steps parallel to the Y axis at the boundaries of each pass. Even more surprising, when I reverted to making the passes parallel to the X axis, as I usually had in the past, there were NO steps! This is exactly the opposite of what I would expect....
BTW - Finally got a little free time to make progress towards finishing up the auto-oiling system. I'm modifying my 14-way selector valve to be operated by an small air cylinder and ratchet mechanism. I have a working prototype of the new valve, and just need to make the final version. Once the valve is done, a little firmware will give me a completely automate pressure-fed auto-oiler capable of delivering a programmable, metered amount of oil separately to each of the 13 oiling circuits, based on spindle on-time. Finally, no more manual oiling! I'll post pictures when it's done.
Regards,
Ray L.