Spindle speed fine tuning

[murilolana]

Hi everyone,

Today I finally got the C11G analog output to "talk" to the VFD, but I still need some help with spindle speed fine tuning.
I've followed the steps of the support doc available in the forum and got a good result on the high rpm settings, but accuracy gets bad as I low the rpm...
If I give a max speed command, I get 10,03V at the output, which makes the VFD to run at 400Hz, but if I command half the speed I get 197Hz when it should be 200Hz and that difference get bigger as a low the speed. If I set the speed at 10% of max I get 35Hz instead of 40Hz, and in this case, the difference is about 300 rpm.
So, the linearity is kind of OK but a little displaced at its botton.
I wish to know if is there a way to fine tune this.

Can anyone help me with this?

By the way, I'm using a KL-2200 spindle with the KL-VFD22 (Huanyang VFD), C11G bob, SS, G320X drivers.
Here is a picture of the components pre-assembled for testing and configuring:
Thanks.

[ftomazz]

Hello,
I believe that you cannot get better than that in the relation from the C11 to the VFD, this is, the analog signal that will enter the VFD should not get better.
What you can try, and I do not know if your drive have this available, is to tune the gain in relation to the analog input, this way you can control better what you want. Im my case I stay happy with 2Hz difference.

Filipe