Originally Posted by
JohnT1
I am using Mach3 to control one of those cheap 500W Chinese spindles via a uc-100 and Gecko 540.
With the spindle disabled at the VFD I am getting 0 to 10 volts at pin 8, proportional to the spindle speed percentage as set in Mach3. Just like you would expect.
If the spindle is then enabled at the VFD, the output voltage drops to about 5.8 volts on pin 8, and the spindle runs at only about 70% speed even though Mach3 is set to 100%.
Now for really strange part.......
If I just take the tip of a screwdriver and just touch pin 7 on the Gecko, the voltage jumps up to 10v and the spindle speeds up to 100%. If i then stop touching pin 7 the voltage drops to about 9 volts.
Similarly, If I touch pin 8 with the screwdriver, the voltage drops to about 2 volts, and returns to about 5.8 when I stop touching it.
The spindle works fine when controlled locally at the VFD over it's entire speed range, so motor loading doesn't seem to be the problem. I have also verified that all connections are tight and the local speed control pot on the VFD is disconnected when hooked up the Gecko. Changing the settings on the Spindle Pulley in Mach3 makes no difference.
I sure would appreciate any suggestions relative to the source of the problem and the means to fix it!
Thanks In Advance for any help!