Hi Tweakie
I did not get to the tool problems yet :-)
I tried today again, and it seems that that my gantry that is moved by one anti-backlash nut is twisting so I get the 0.4-0.5 backlash on mu X axis.
Checked with the D.T.I (you see - I learn fast) the other axes - they were almost perfect - 0.01 to 0.03 backlash.
Took the top part off - and checked the backlash of the X axis by the nut - was almost perfect. Checking the other side of the gantry (one that does not have a nut) - I got this big backlash again.
I guess my best option will be to get another nut and put it on the other and opposite side - this will hopefully eliminate the problem...at least until I start cutting :-)
So I am relieved this is not a problem with the screws and the nuts - hope this will solve the problem.
Thank you for your time and assistance
Isaac