Spindle VFD woes

I got an older machine (01-2015) it has been working great for years but last night I was making some christmas pens and when my spindle shut off after an op it kinda coasted to a stop more than normal. Now it will not turn on. I read the manual and the online trouble shooting guide and it looks like the VFD is shot. I have voltage at the VFD so no other safety or switch is not working and I checked the resistance of the motor (in spec). I checked the replacement parts for the 15L on tormach and it looks like they don’t have the VFD listed and when looking up the Emmerson Commander SK online it looks like that model is obsolete. So how screwed am I? Has anyone replaced the VFD with something like an automation direct unit or does the 1100 have the same VFD? Should I check something else?

Download the manual for the SK. Go through the entire parameter list and write down the values and their description. Buy the closest model emerson sells or a used Sk off of ebay. Reload the new unit with the same values and see if it works. Emerson has very good tech support. If you call them with your parameter list they can probably walk you through setting up a new unit.

I’m getting power at the unit but no lights or codes so I can’t pull the values I would have to figure them out from the documentation of the control board. I sent customer support an email but I know they are out right now.

I can look at the parameters on mine if need be. I will have to look at the VFD and confirm that we have the same model.

Looks like you can have your pick from 150 dollars to 1500 dollars on ebay.

A VFD for a current model like that is something we should have in stock even though it’s not on the website. I’ll check and report back here when I get back in the office Tuesday.

@Tom_Detka we have those in stock and at the time of this posting the price is $588.07 with PN 51126. Contact our Orders Processing department to order.

There are a number of parameters in the VFD that are locked out to the user and only changeable by Tormach. That should be taken into consideration with an eBay unit. $600 for a new unit is likely preprogrammed. But I would hope Tormach would offer a programming stick at a reasonable cost for a used VFD.


Programming sticks are quickly becoming rarer than hen’s teeth, Nidec discontinued them a while ago and there is no replacement or alternative from them. However, theres no reason we cant upload the parameters for the 15L to github, ill see if i can find the par file on the server and grab a pdf of the parameters for Engineering to upload.

Thank you

Thanks so much everyone I’ll have to get in contact with sales in the new year to get the VFD ordered. Since I got some people looking here I might as well ask another question. Is there any servo upgrade kits for the 15L? I really love this machine and the control but I really hate the rapids.

Unfortunately, not at this time. While we always have our sights set on the future a servo upgrade for the 15l is not slated for release in the near future.

I sped up mu feed rate so that I could do some acme threads at a higher rpm to improve surface finish. once yo reach a relatively high feed rate the 15L starts to oscillate on the ways to the point that the stepper loses steps. A servo would not be able to overcome that.


What kind of oscillation are you seeing and at what feed rates? Loosing steps purely due to feed rate is not a common scenario on the 15L, provided all of the other cutting parameters are within the machine capabilities.

Thank you,

Oscillating of the cross slide on the dovetail ways causes it to slightly seize during fast feed rates. I did not realize it was losing steps until I noticed where it started feeding for the thread. I stopped the process and checked program zero. It had moved substantially Z+. Thus missed steps. When I called Tormach to ask about increasing the feed rate they told me it was a possibility above f30… It is a known issue.