You are the second person in a couple of weeks that contacted me about using these for linear motors. I have had limited success. Granite Devices suggested reducing the resistance and/or inductance to values that are fictional. This allowed me to reduce the noise, but I have not had a chance to retune all my motors, so I don’t know yet how that affects performance.
So my take on it is this: I have a lot of servo drives and motors, 5 of which are IONI drives. I am using these IONI to drive 3 different types of linear motors. I have had them for a year or two and periodically tried to re-tune them, because of how quiet my other servo motors are. I felt like I was doing something wrong. None of them are acceptably quiet at this point in time. I cannot speak for other motors, but if you plan to use Parker MX or Trilogy linear motors, I cannot recommend the IONI. The best options are to either get a used drive on ebay from the motor manufacturer, or to go with a Kflop/Snapamp.
Another thing to consider is that the tuning is a bit weird for granite devices. Commonly, for a servo drive, you get to change P,I and D values, as well as feed-forward parameters, and one or more IIR filters, dead band, etc. The granite software does not do it that way. You get an option combination that was quite unfamiliar to me:
P and I for the velocity loop,
P for the position loop.
feed-forward gain for velocity, acceleration and position. They may be related to some of the ‘D’ values but the software does not explain…
Nor is there any sort of step-response/frequency analysis or IIR filter to use such information with. You only get a torque bandwitdh limit, but no facility to decide upon the frequency other than your own ears. Tech support told me that there is some sort filtering below some frequency choice for that limit, fyi.
I see no dead band settings, so you sacrifice some performance if you want to avoid hunting around zero.
It’s not all bad. The IONI have some very cool features, such as real time monitoring of the setpoints and tracking errors, and the fact that they can do Sin/Cos encoders without external hardware. They are also very small, which is nice. When the drive does not work, Granity tells you pretty exactly what the problem is via fault codes. Also, the Granity software loads very helpful documentation from the internet while you change the settings, and in general is far more user friendly than, say, the Parker C3 Servo Manager software .
Hope this helps.