Hi there, We bought a 2nd hand cnc and we don't know anything about it. We have a local friend that hrlps out quite a bit but we don't always want to worry him by asking for help. We will have to learn ourselves. Is there a guide or something we can use to educate ourselves with a cnc router? So the current problem is all of a sudden the router is losing it's mind and not cutting what it is suppose to. What can be the problem? I am attaching photos so you can see what was suppose to be circles. Any help will be greatly appreciated Thanks Maryke&Pieter
Hi, Common reasons for what you are seeing is that the stepper motors are losing steps, or a coupling between the motors and the position drive is slipping. Do the motors make some grinding or banging noises occasionally? Try running the same programme, but do not but a bit in the router so that it just 'cuts air'. Whatever the outcome, it is very worth checking all the motor shaft couplers are tight, just in case. If the machine moves 'in the air' as if it would have cut the circles correctly, then it is most likely that the forces on the bit were too high for the machine, causing the drive motors to stall, or shaft couplings to slip. Reducing the depth of cut or slowing the feed rate will reduce the cutting forces and it may be that the cut you tried was just too aggressive. If the cutting parameters were conservative and should not have caused any position loss, then first check that all grub-screws on couplings are tight. If there is still a problem, it is possible that the motor drivers are not configured properly: re-configuring the motor drivers is not something to adjust until other possible problems have been investigated though! If the machine still loses position when it is 'cutting air', then it is very possible that a drive coupling is loose, so check all those thoroughly first. If all the couplings are tight, then it may be that the machine is trying to accelerate too fast and the motors are stalling. The acceleration limits are adjusted through software, and it will depend on which machine controller you have if you need to try that. There is also the possibility that something is seizing or jamming, putting a very high loading on a motor. There is also the outside chance of one of the motor wires having an intermittent break. Jogging the machine around the workspace often reveals an issue where suddenly one of the motors seems to either lose power, or could even appear to step in the wrong direction. There are usually 4 wires to each motor, and if any one of them breaks, the motor will still often move, but with reduced power and in an erratic (and noisy) way. Evan
