Hi all again. Having got past the 1st thick stage, the machine is set up with limit/homing switches, the safe limits are set up, but rarely get used as the machine is a small cnc6040Z and to date every sign I have cut has activated the safe limit so I tend to leave that button inactivated, I have not understood offsets or set any up, although YouTube makes it look easy, it still goes over my head so I just zero the milling bit to my job everytime. I have settled on Inkscape and JScut and for the simple jobs I am doing at present it suits my needs, but I am going to look at Vcarve later on.
Anyway the problem I am having with my machine is that when I start a job and I am happy all is ok with the cutting path, the mill is not going to hit any clamps, screws or such like, I tend to leave it going and get on with other thing in the workshop, very often I find that the milling bit is cutting fresh air when it should be at least 3mm into the wood, the Mach 3 readout is exact and reading what or where the Z axis should be, I then have to return it to zero and restart the programme and watch it making manual adjustment on the stepper motor to keep it at approx. the correct depth, ok on the signs I turn out.
I do not have the answer as I have not looked at the mechanics but think it could be the coupling slipping each time the Z axis goes up and down each time it passes over a tab or to a new place on the job. Could this be the problem and how do I fix it? if not what else can it possibly be?. One way to stop this happening is to slow the feed rate down, but this makes the job really lengthy causing the motor to get hotter than it should, as I am not using the water cooling, as I have no heating in the workshop and there is a risk of freezing, to this point could I use antifreeze, will the small plastic/ neoprene tubes be ok?