[rewster]

I know this has been covered in some detail in many other threads, but I haven't found anything describing the problem I'm having. I just rigged my x2 spindle to my g540. P1, P2, and P3 to ports 7,8,9. I can control the spindle in mach3, but it does not run smoothly. You can hear the rpm's fluctuate, and the spindle now stalls easily. I just stalled it while doing a .02" flycut in Al.

My pwm settings are 50hz, 20%. Spindle pulley settings are 0-3000 rpm, 1:1. I've been advised that my problem is most likely due to the pwm setting, but I can't find any recommended values in the gecko literature. Please shed any light you can, thanks. :cheers:

[hoss2006]

Minimum PWM should be 5% according to Pminmo.
G540 VFD
Hoss

[rewster]

Hoss, you're a saint in a common man's shoes. One who, apparently, doesn't sleep. Thanks for the helpful reply.

I got the 20% value from another thread, from a poster who was having similar problems. I kept getting a "pwm bumped to minimum setting" message. I had tried pminmo's .xml file but it failed to work. I revisited the problem in my current xml and it seems to be working correctly now, but I have to play with the settings every time I open up mach. For some reason it's not saving all of my settings, ie spindle pulley settings. Not a huge problem, just takes a few extra seconds upon startup.

[rewster]

Hate to cry wolf, but my problem persists. It now runs smoother at low rpms, but when I increase them to what sounds to be half power (no tach to check exact range) it starts running unsteadily. 50hz, 5%. Any other ideas, Hoss?

[Fastest1]

I do not understand the problems you are having but shouldnt that 50Hz be 60Hz in the US? Of course I could be way off.(chair)

Hate to cry wolf, but my problem persists. It now runs smoother at low rpms, but when I increase them to what sounds to be half power (no tach to check exact range) it starts running unsteadily. 50hz, 5%. Any other ideas, Hoss?

[hoss2006]

The pminmo settings have worked for other X2's but I checked the G540 XML,
maybe they still just have it at some random default setting but their numbers are the opposite pmnimos,
PWM base freq, 5, Minimum PWM 50%.
On saving, do you have mach installed in the default directory?, if you make changes it should ask you if you want to save fixture.
Hoss

[rewster]

I do not understand the problems you are having but shouldnt that 50Hz be 60Hz in the US? Of course I could be way off.(chair)

Please enlighten me, why would this be? You could be right. I'm electrically incompetent.

Hoss, I noticed that too but figured it was just a default. I will try swapping the values and see what happens. Also, what should my spindle motor tuning setting be? I have 2500 steps, 120 velocity and 4 acceleration....again, per the setting of another user.

I was going to hook the pot back up just to be certain I don't have a power supply problem, but I didn't take note of which wires went where when I disconnected it. I guess I'll dig up a wiring diagram of the x2, if one exists. My roomate is an electrician and I'm having him double check the circuits in my shop. I have no reason to believe that my problem is in my power supply since everything ran fine before I wired up the vfd.

Also, I disconnected all 3 P-wires but pminmo suggests leaving p1 and p3 connected. Could this have an effect?

Thanks for the replies, keep 'em coming if you have any other ideas!

[Fastest1]

60Hz is the US electrical standard. 50Hz is used in Europe and other places. However these are supply voltage parameters, regulating the speed of a motor can probably be done a few ways ( I have no knowledge in this area). I do know I have a VFD on a 3ph motor and it regulates the rpm by varying the output frequency, hence the name "variable frequency drive". I also run a drive for a DC motor called a Bardac 1600I but it has been so long since I looked at that project, I forgot how I got it to work originally. I sure hope I took a few notes! I am sure it will be obvious when I get back on that project. LOL

[LatheMaster]

I'm thinking about getting the g540. Was wondering what sx2 you have. I got the little machine shop one. Does yours have the brushless motor? I'm somewhat electronics incompetent.lol