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Fadal speed stepping down and belt bark on spindle decel

macds

Hot Rolled
Joined
Jul 24, 2008
Location
Milverton, Ontario, Canada
Recently I've noticed that if I run the spindle up over 8K rpm, and there is a significant speed change or an m5, the drive steps the spindle speed down. If the spindle is commanded an m5 from upwards of 8K it steps down and then slams the spindle off, resulting in belt bark when it stops.

The spindle is a brand new unit, only a couple of months old. Nice and quiet.
I've looked through the manuals and searched online but I cant find anything regarding this.
Only happens over 8K, which sucks when I'm doing a lot of fine detail\engraving type work.

Any opinions would be appreciated.
 
It shouldn't have anything to do with the spindle.

I'm assuming standard Fadal control??

1st parameter page.. RPM factor, try jacking that number up.. I swapped some
boards around and had that problem recently, nice big screech, going from a
1 to a 5 fixed it.

If that doesn't do it, you're going to have to crack into the spindle drive and
play with the ramps in there.
 
No dice Bob.
Tried different numbers between 0 and 31 (it was 0), and the only thing it changed was my spindle speed at 100%

Tried the overload parameter as well, same behaviour.

Unfortunately for me, my baldor drive is missing the programming console....
Guess ill be programming my own spindle speed steps with delay timers for the time being.
 
Could be a transistor module in the drive on the way out. It could be turning on the braking all at once instead of modulating according to the decel parameters.
 
Looking to bring this back to the top.

Thanks to D Nelson. i had no idea the idlers were supposed to be air over oil.
I added oil as per the service manual, and there is an improvement in that the belt no longer barks on decel, but over 8500 rpm I'm still getting that stepping down BS.

Braking resistors check out good.

There has to be something else going on.
I know of one other fadal that has the same issue, but slightly worse.
Spindles were recently changed out in both.

Would one need to go through the learn procedure on the drive after a spindle swap on a rigid tap machine?
Both machines are RT, recent spindle swaps, and exhibit similar symptoms. Both were fine before the new spindles.
 
An update.
The fix on buddies machine was a blown fuse behind the panel on the spindle drive. Glad he found it!
I havnt had a chance to look into my issue yet, his was much worse.
 








 
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