[bobmagnuson]

I'm upgrading my router, swapping out the steppers for ClearPath Servos, ATC spindle, UCCNC, etc.

One of the things I wanted to change was that when powered off, my spindle would drop due to weight. Not a huge deal, but I'd like to correct that.

I purchased a Inertia Dynamics 24v brake, MPC23 model, off eBay (maybe that's the problem) that interfaces between the server and Z ball screw. It works fine at very low speed, but if I increase the speed, I'm getting resonance or binding.

I've swapped out the brake and connected the servo directly to the Z ball screw and it moves very smooth. That narrows it down to the brake.

The brake I purchased has a C face which makes the whole thing very easy to assemble. I took the case apart and inside is model 1702-0038 brake which I can't seem to find any record of anywhere.

I'm looking for suggestions...

Leave the brake off?
Try and replace the internal brake part?

Or does anyone have experience with these type of brakes?? Are they smooth running at higher speeds?

***I should point out that I've also got a air cylinder counter balance that works to keep the spindle from dropping. The brake is a redundant backup in case of air pressure loss while the machine is powered down.***

[Jim Dawson]

Assuming the brake is powered when the Z axis is energized, then it should disengage and run free. It could be that it is set up a bit tight and you maybe need to back it off a bit.

[bobmagnuson]

Assuming the brake is powered when the Z axis is energized, then it should disengage and run free. It could be that it is set up a bit tight and you maybe need to back it off a bit.

Yes, the brake is powered (disengaged) when the z is moving.

How would I adjust the tightness?

[Jim Dawson]

I can't find a manual on that brake, but everyone that I have seen has a method of setting the air gap. If you bought it new, it should have an instruction sheet

[bobmagnuson]

Jim, after further investigation, I think the problem may actually the tuning of the ClearPath servo.

The servo I'm using is a CPM-SDSK-2321S-ELN which has positioning of 1/6400. In the tuning software I've got it set to 6400 pulses per rev.

I've looked at the ClearPath manual, and I'm missing the correlation between the ClearPath pulses and how it's set in Mach3.

Though in Mach 3 motor tuning, it's defined as Steps per inch of Z travel. It's 1909 in Mach3.

Getting more confused as I type!

[Jim Dawson]

As I recall the last Clearpath I setup, I set the motor to 6400/rev and then multiplied by the leadscrew pitch and set the PPI in the controller to that value. This was on a MultiCam router and it's controller so a bit different than Mach3.

Did you run the autotune on the ClearPath?

[bobmagnuson]

Yes, I had run the auto tune on the ClearPath, but ran it again last night. Not sure what the difference was, but the auto-tune worked much better the second time around.