Question regarding Tuning Servo motors

Hello Everyone,

Here's what we have:

3 Homeshopcnc Nema 34 850 oz/in 72 VDC servos with 250 count encoders.

These are mounted on the x, y, z axises of our Hurco cnc mill.

We are using Gecko 340's on a Lococnc BOB.

We have all of the belts to the ballscrews disconnected in case of a
run away...do not want to break anything, and will mount the limit
switches later.

When trying to tune the servos, there seems to be a very narrow range
for adjusting the Limit, Damp and Gain to be able to get the servos
to run without Faulting the Gecko.

My electronics engineer is thinking that the servos need to have a
load on them to tune properly and wants to hook up the belts to drive
the ballscrews...

We have had several runaways without the ballscrews hooked up and I'm
concerned...

What is the proper way to tune these servos?

Best Regards,

Preston