Siemans Servo brake

Posted over on the CNC forum, but thought since its relative machine specific, i would also ask here....
My FP4NC has Siemans HU 3078 permanent magnet servo motor on the "Z" axis.
This servo is fitted with a permanent magnet brake that is engaged when not powered by the grip of the magnet to a steel faced coil.

When the coil is energized the magnet is repulsed and the brake is free...and the servo allowed to turn.
On my machine this magnet is weak. Easily overcome using the hand wheel with the power off...Something i can't do on my other FP4NC.

Any one here with personal experience re-charging this sort of magnet? Can it even be done?

Hoping to avoid having to remove the coil/magnet as the wiring is a bit tedious to remove and install....

Cheers Ross

FWIW I put a new brake on my FP7NC. It is a separate item, not integrated into the servo. Every source I asked about how one of these would get demagnetized or how I could remagnetize one answered that they had never heard of this happening.

Well, here is another instance..so now there are at least two in the universe...
I am aware (intimately) with how the brake fits up...Just hoping to do something in place without pulling it out and screwing with the wiring...

Where did you find a brake..Was it NOS or used or?

Cheers Ross

It was from SG in the UK - Electromagnetic Brakes Archives >> SG Transmission
They built it special order. SHW offered to get me one, but the lead time was longer and the price much higher of course. I found SG by looking at google images of electromagnetic brakes, couldn't find any info on it any other way. Mine only has 2 wires, ground and 24VDC. If I wasn't clear, it's not inside the servo, it's attached to a shaft that goes to the ballscrew gearbox,

I saved the old brake, it still has a good bit of drag when applied. I plan to mount it to the shaft of my #6 arbor press to hold the ram in the up position and use a foot switch to release it.

If you can find the mfg of your brake, you can likely find a spec for the ft/lbs of resistance it has when applied when new and compare it to yours, that's how I determined for certain mine was not working properly.

Did you look at the air gap and travel of the brake? I don't know what the specs are for yours, but there needs to be enough travel in the brake disc mount to allow it to contact the brake armature plus a bit. If the disc is held away slightly because of wear, that could cause a weak brake application.

When not energized, the brake is held by springs, when energized there is an electro magnet that releases brake. If it is slipping, you most likely need new pad/disc, could be weak springs, but my money is on pad/disc. I've done many on Fanuc motors, no Siemens, but cannot imagine too much difference.

No springs on this setup. Think you are confusing this brake with the drive motor brake...
Near as i can tell there is no adjustment for gap either.
Cheers Ross