Spindle Control - Omniturn G1/A attachment.

I've recently acquired an Hardinge TFB w/ an "A" omniturn attachment. It's got the original vari-speed pulleys and spindle motor, which I would like to remove and replace with 10V VFD if possible.
Omniturn support only offers to upgrade to the latest controller, which I understand, but it's not gonna happen.

So before I go the DIY control route, anybody have any idea on how I can get 10v for a VFD?

The controller has the old 2axinterp card & spindle control card, and if I'm reading the schematics right, pins 10 and 11 on the Misc cable should be tied to analog control for the spindle.
I checked the pins for voltage after executing various spindle commands and it read a consistent 11 volts??
Additionally, I was unable to locate any adjustment pots for spindle voltage, which maybe it doesn't have.

If anyone can point me in the right direction or give guidance, I'd appreciate it.


The spindle & connect cards:

A little it surprised that Omniturn will not help you. I have 2 that were purchased back in the mid 90s. One has VFD and the other does not. Both controls look the same, with spindle on/off and speed controls. Many years ago I replaced the drive and they lent me a device for setting the spindle speed correctly and gave me all the advice needed to complete the job.
still give advice to finish this project.
Maybe you need to call again when one of the older fellows with experience on your control is available. Also try Richlin, they are not far from you and are rebuilding and servicing the old attachment machines.
I just opened up my control box on the VFD machine and the control line goes to a terminal strip with 30 sets of wires. Most of the terminals are used but I am severely color blind so I will not be much help in tracing the wires. I Just looked at terminals 10 and 11 on my strip and no telling if they correspond to the 10 and 11 on your cable. On both sides they go into bundles going up, neither down towards the VFD.

Just for meaness I started the machine with no spindle control and checked the voltage on pins 10 and 11 of the Misc. connector and found no voltage with a program running with an m03s1400 command.
Turned the spindle on and off, ran the speed control up and down with the spindle switch on and saw nothing but a small stray voltage.
My voltage tap is a solid 16 gage wire stuck in each wire receptacle.
Can check other numbers if you give them to me.

I've sent an email to Richlin. They are all over the manual, so I think the attachment came from them. Worse case is a DIY conversion of some sort.

I did some further looking and have some documentation with the one with VSD. If you can get wiring diagrams and voltage info this may help you. The wiring is much more complicated on the old AHC with VFD than my recently purchased kit for the HXL also with VFD. Is it possible to upgrade your new control with just a couple of boards?
I will take a couple of photos to show you the difference.


The photo on the left is the new HXL, the transformer on the bottom is for the 120V to the control and I may pull it out, the loose wires are for power and coolant pump not installed yet. The circuit board in the middle seems to have eliminated the need for all the bundles and most of the relays in the older machine. Most of the 30 positions on that terminal strip on the older AHC are used and there are so many wires in the bundles they could only be traced with difficulty.
We still use the machine without the VFD and the main thing it can not do is auto tapping. Let me know if you want the documentation and I will have my secretary convert them to PDFs for email.

Thanks for posting this info. Don't worry about having any documents scanned. I've received an email from Richlin so we'll see what they say.

As of right now, I'm getting voltage on pins 10 and 11 (the right pin 10 and 11 now, lol). The voltage is still always 11.23 regardless of speed when a spindle on command is executed. The spindle override pot on the front does affect the output.

I have been unable to locate the adjustment pots, to see if that's an issue.

Maybe there is a parameter to initiate the spindle speed control? Seems pointless to have it operational on a machine with out speed control.

I actually just noticed that the voltage is present as long as the control is up and running, even prior to M03, etc.. But the pot still controls it.