Hello everyone. I would first like to thank you again for helping me with my last problem. I am VERY new to CNC programming. I have written 4 simple programs so far and am starting to get the hang of the TNC155 control. My problem is that after I ran my latest program on a block of wood I decided to try it on some aluminum. After starting the program it looked good at first and then started on a totally random pattern. I stopped the machine, lowered the table, and started the program over deciding this time to only cut my pattern .002 deep just to check it. This time it followed the pattern as it should so I lowered my Z down a little more and tried again. Then it did the random pattern again. I lowered my table and tried the program 2 more times and it did different things each time. A couple times it gave me an error stating my tool radius is too large. I then powered off the machine for 10 minutes and restarted it. This time it ran my program as it should. I then raised the table and hit the start again and got another random pattern. At no time during any of this did I ever change the actual program. I only raised and lowered the table by hand. Any ideas?