G0752 & Delta VFD-E

[Gary Campbell]

I'm looking for some "shots in the dark" from those with some VFD experience. As the title says I have a VFD-E controlling the spindle motor on my G0752 lathe, which I have just converted to Acorn control. I am trying to get the spindle speed somewhat accurate, to no avail. On the 1:1 high speed pulley minimum rpm is ~250 and maximum is ~2150. Measured with the onboard lathe tach and a handheld digital tach, which are +/- 1%

No matter where I set the rpm band in the Wizard (low at 0 to 500) I cannot get set rpm (in CNC12) to be even close.

This is further complicated by what appears to be either inop parms in the VFD or a programmed lockout of the keypad (which I purchased just to try and tune the rpm) Analog gain parm 03.04 (20-200%) changes have no affect, neither does a DIP switch (AVI to ACI). Parm 00.02 is set to "0", read/write

Any ideas?

[diycncscott]

Can you please post a report from your system?

Pretty much the only parms you need to change in the Delta are your motor specs, accel/deccel times, control type(remote 0-10), and max frequency.

[Gary Campbell]

Scott...
In reality I didn't have to change anything. The machine has been running fine using the VFD's onboard 10vdc and potentiometer. I ordered and added the digital keypad when I couldn't get the lowband end of the rpm anywhere close to programmed speeds. At the time the following report was generated rpm is set at 10 (lowest) and voltage across DCM & AVI is .08vdc

[Gary Campbell]

After some further testing, it appears that the issue must be in the VFD. Using another Acorn on the bench with the same spindle settings, my lathe Acorn outputs .015 v higher at same rpm low band and decreases to .011v higher at the high end. Both should be more than acceptable (under 1.5%) I need to find out if there has been some Modbus programming that has keypad changes locked out. This assumes Scott didn't find an Acorn parm that I muffed

[tkbot47]

After some further testing, it appears that the issue must be in the VFD. Using another Acorn on the bench with the same spindle settings, my lathe Acorn outputs .015 v higher at same rpm low band and decreases to .011v higher at the high end. Both should be more than acceptable (under 1.5%) I need to find out if there has been some Modbus programming that has keypad changes locked out. This assumes Scott didn't find an Acorn parm that I muffed

Gary, how did you end up resolving this issue with the G0752 VFD?

[Gary Campbell]

I've learned to adjust my speeds. That said, I have been in touch with Delta Techs and have been given a few things to try and unlock the parameters. I'll let you know what I find, but it might not be for a week or so.

[tkbot47]

I've learned to adjust my speeds. That said, I have been in touch with Delta Techs and have been given a few things to try and unlock the parameters. I'll let you know what I find, but it might not be for a week or so.

I'd be interested in what you find out. Did the keypad not work at all? Is this "lockout" something that Grizzly did? What did you learn about how you can adjust speeds without the param adjust?