CNC router from industial scrap

How is the VFD controled?
I have used several of water cooled and air cooled 2.2KW spindles controled by analogue voltage from Mesa 7i76E, never had issues with speed.
Had issues with water cooled ones leaking, though.

The VFD is controlled as standard analog 0-10V, connected with shielded wires, shield grounding on the drive side. I tried different grounding options, added ferrite rings, changed different wires, I thought it was some kind of noise problem, but no luck at all.

If the VFD has a large capacitor on the analog voltage input, it could
possibly cause instability and high frequency oscillation on the analog output,
so one thing to try is adding a small resistor in series with the 7I76E SPINOUT pin
(say 220 Ohm or so)

Trying with 120, 180 and 330 Ohm resistor, nothing change.

I haven't posted anything for a long time, but I haven't been idle, and I've been able to do some interesting projects over this time.
The first project was a deep modification of a computer case with custom water cooling system. It was a very challenging job for me, many things I did for the first time. Starting with the general idea, the design, the making of all the details and the final assembly I did by myself. I gained a ton of experience from that case and now I'm not afraid to take on complex projects. 
   
 
More pictures here -  ibb.co/album/4snsH2
The second project is a 5-axis machine to make wax models for jewelry. Similarly, all design, manufacturing, assembly and adjustment was done completely by myself.
 
   
 
 
 

 

You do very nice work.

Awesome!