y axis

[GlenP]

Hi all. I have been putting up with a minor issue but now want to know how to make it right. My PRS 4896 Standard seems to be cutting my parts about 1/16 undersize only on the y (48") direction. Not sure where to look first or if it is anything that can be corrected. It is consistant anywhere on the table. I am thinking this might be a software math and rounding issue??? When i look at my Unit values they are both the same for x and y (1833.465). I have 25 tooth pinions on both axis. :confused:
I am cutting 3/4 melamine at .25 depth and 3 ips.

Never mind....fixed issue . Can't asee how to delete the post??

[srwtlc]

So, how did you fix it? Inquiring minds want to know. ;)

[GlenP]

Hey Scott. Wasn't really a fix as it was more of a different cutting technique to get the part size correct. I did some looking at other threads and found where Mike Richards and Gary Campbell mentions cutting the part in climb cut first at around 80 - 90 % deep and then do a final pass conventional at full depth. I have been cutting my melamine material in conventional as I find it gives me less chip out. I use fluted end mills as they are available in my area. I am going to try down spiral later today or tomorrow.

[Gary Campbell]

Glen...
Using my current suppliers melamine, which seems to be very brittle, I have switched to making 2 conventional passes down to the onionskin. (47%) Then a last pass, also conventional, to cut the skin. This allows me to keep my cut speed up and not burn up bits. Previous method of full climb pass to skin started to show chipping after 12-15 sheets.

I am using Compression bits at 6.67 ips 14K rpm.

Note: If your parts are offsize in one direction only, I would suspect a mechanical issue. You may compensate with a better cut stategy, but look at the adjustments.