Machine Tuning as Preventative Maintenance

I like to fiddle a bit with my machines every now and again to make sure they’re adjusted to tip top condition. The CNC mill seems to benefit from this the most. For example, the gibbs and sometimes the Mach3 motor tuning parameters benefit from periodic adjustment. Perhaps surprisingly, the tuning varies depending on conditions.

When its cold (like it is right now in my area), the mill is stiffer and seems to require lighter settings. When I load the table with two 6″ Kurt vises there is enough weight to slow it down too. Right now I have the combination of both, so things are kind of “worst case”, at least until I decide to throw a cylinder block up on the table and try to machine on that!

In addition, Z is the most sensitive (being the heaviest), followed by X, followed by Y.

So my current settings, which I regard as a worst case, are as follows:

X 110 IPM, 10 acceleration
Y 120 IPM, 15 acceleration
Z 110 IPM, 10 acceleration

I generally just leave Z right where it is. However, if the weather is warm and the table is lightly loaded, I may bump X up to 120 and 15.

It’s concievable things can be made to run faster, but I like to keep my gibs very tight as well. BTW, they sometimes need readjusting too. The original owner of IH, Aaron Moss, once told me he retuned his gibbs every season. I can definitely believe that.

Something else that helps is a machine warmup. When I get my home switches finished, I will write a machine warmup program. The idea is to move the axes through their full range of travel for a period of time, and warm up the spindle bearings as well. This practice is common on full-sized VMC’s, and there is no reason it wouldn’t be helpful for my little mill too. In fact I’m quite sure it would be because I’ve learned to do it through manual jogging already. It would be even nicer to have a program run while I pump the oiler every so often to make sure plenty of way oil is being spread over all the surfaces.