VFD to replace Spindle Drive

[jiml3412]

I am working on a very old CNC with a Yaskawa Spindle Drive that is having problems. I was wondering if a common inverter with open vector control could replace that unit? All the wiring, specification, and operation look very similar to inverters I use everyday. Has anyone tried this?

 

[jraef]

It's done all the time, a very common application for sensorless (a.k.a. open loop) vector drives as it is not a positioning or zero-speed application. In fact, many spindle drives were retrofitted with scalar (non-vector) VFDs with reasonable success before sensorless vector technology became somewhat ubiquitous and inexpensive. The addition of vector control solved a lot of low speed torque related issues.


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[DickDV]

Since there are a lot of different types of "spindle" applications, it would be good to review just what your no-load to full-load speed stability requirements are. Also, take a look at any requirement for smooth spindle rotation at very low speeds (say, under 100rpm) and high torque.

I would say that those areas will be the most likely limiting factors in making this switch.

 

[jiml3412]

This all sounds like good information. I suspected the change could be make so I will try it out.

 

[ozmosis]

If it is a "high speed" spindle then check the minimum speed/frequency limits as often high speed spindles have limited cooling capability at low speed due to the design of the integral cooling fan. The fans are designed for low inertia and thus their ability to 'blow' air is not too good at low speed.