On 11/05/2011 7:15 AM, andy pugh wrote: > On 5 November 2011 12:09, Viesturs Lācis<[email protected]> wrote: > >> I have a suspicion that this might be something connected with Mesa >> card and magnetic field from VFD and also spindle motors, because >> there is CRT monitor ~0,5m from spindle motor and the picture gets >> creeped. It is good as soon as motor is turned off and gets creepy as >> soon as it is turned on. The pattern of creepiness changes as the >> motor moves. >> > I would try to get a line filter installed on the VFD supply as a > first stage. That probably isn't the problem, but it sounds like it is > required. > Oh, yes, this may not be it, but VFDs are well known to cause problems from either radiation or conduction through the power lines. I have seen it, too. It did not cause problems, but did put "snow" on the CRT. That was a sign there was a lot of conducted RF interference. A line filter cleared the problem up.
One test you can run is to run the machine without the VFD powered on. You can make ]a program that finds a spot and maybe makes a dimple in a piece of material, then does a large number of back and forth moves, and then returns to the same spot to see if position has drifted. If there's no error with spindle off, but errors with spindle on, then interference from the VFD is almost certainly the cause. Jon ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
