errors in cutting on my prt alpha not sure what caused it.

[knight_toolworks]

the machine was made the last year shopbot made the alphas. it has run fine the whole time. had some issues with the serial to usb adapter and a new one fixed it. I have went through two or three computers on it and a couple of hubs.

I have seen in the last few months where the machine stopped like it hit a stop or the bit was dull or it could not plunge all the way because the dust brush was in the way. but this morning I had it happen using a 1/16" bit a couple of times. I turned the machine off and restarted the software and it seemed fine.
but then I cut these parts it is a simple plug with the pocket centered I have cut thousands of these. but the cut changed with the 1/4" bit cut some are off center but some are ovalized. when I brought the machine home it is in the right position. So I am not sure what to do. I rebooted the computer and the shopbot it took a bit of unplugging the usb cable to get it to find the port.

so I am wondering buy a new cable replace the usb to serial a new hub all three? or could it be just a worn out machine? I plan on getting all three new things but I am worried it will start this again.

I dont usually turn off the computer I leave it on all week and put it to sleep on the weekends. its a pain to log into so its a pain to t urn it off every week.