Re: Tormach PCNC 1100 Spindle Question #3 (VFD Settings???)
Well if you were getting unusual vibrations at a displayed value of 5000 rpm, but you were actually at 10000 rpm, I guess you just discovered the source of the vibrations.
Check out the following:
Parameter 1. Max motor freq. Should be 170 Hz.
Parameter 7. Motor speed. Should be 1715.
If the Max motor frequency was set to 340 Hz, than commanding 2500 rpm would actually get you 5000 rpm (which you saw).
I am not sure if parameter 7 could be related with the mismatch between commanded speed and actual speed.
The Commander has 18 layers of menus, but it is set up to only easily access the first layer (menu 0) from the keys on the VFD panel.
To get to the higher menu levels, you have to edit Parameter #10, Good luck, let me know how that goes. Have you checked these out?
Menu #1 has a frequency reference value
Menu #3 has a "frequency reference scaling"
Menu #7 has "analog input scaling" which changes how the 0-10V analog signal form the BOB is treated, which could mess with commanded speed.
Menu #21 is "alternate motor mapping"
It is very probable that Tormach has stuff set up there that is causing you problems. They don't seem keen on helping diy set up vfd's, probably because it is anything but intuitive.
Maybe the original owner upgraded the VFD to Series III by buying it from eBay rather than from Tormach, and you are left with what he messed with rather than the official setup?
One last thing: have you tried using the same PC on you "new" Tormach (that you are trying to fix) as on your old one? I was just wondering if there is any mach settings that could be causing a problem? Such as the settings for pulley diameters (low speed vs high speed mode).
Originally Posted by
SCzEngrgGroup
VFD speed is normally controlled by passing an analog voltage from the breakout board to the VFD, which defines the desired spindle speed as a function of maximum speed. This is typically a 5V or 10V signal. ...The other method, less common, but perhaps used here, is an RS485 or Modbus connection between the PC and the VFD.
Tormach BOB provides a 0-10V analog signal on the VFD T2 terminal, which controls the speed.
Tim
Tormach 1100-3, Grizzly G0709 lathe, Clausing 8520 mill, SolidWorks, HSMWorks.