Kress Spindle speed fluctuatling randomly?

**Millatime16** · 04-11-2023

My Kress spindle has started fluctuating speeds. The sound of the blade goes up and down occasionally. (doing it more and more)

Is this a brush issue with in the unit? or is it replacement time?

I'm not sure which model it is, but its in use a lot of the time. (its manual speed control, not controlled by Mach3)

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**Voicecoil** · 05-11-2023

Originally Posted by Millatime16

My Kress spindle has started fluctuating speeds. The sound of the blade goes up and down occasionally. (doing it more and more)

Is this a brush issue with in the unit? or is it replacement time?

I'm not sure which model it is, but its in use a lot of the time. (its manual speed control, not controlled by Mach3)

I would suggest checking the brushes first, also take a look at the commutator to check for wear.

**Millatime16** · 06-11-2023

Originally Posted by Voicecoil

I would suggest checking the brushes first, also take a look at the commutator to check for wear.

Thank you.

I bought new brushes and installed them (the old ones were only a 3rd of length left).

Sounds different and wavers a bit on start up.

Do they need a bedding in period?

I guess if it still plays up, its time for a new spindle. Seems the replacement is an AMB 800 FME-Q only available fir Germany.

They seem to have a hard wired lead though. Mine has a connected that goes back to the CNC brain (for stop start). It doesn;t control blade rotation speed though.

**Voicecoil** · 07-11-2023

Originally Posted by Millatime16

Thank you.

I bought new brushes and installed them (the old ones were only a 3rd of length left).

Sounds different and wavers a bit on start up.

Do they need a bedding in period?

They can do in order to make full contact with the commutator: the shape of the end of the brush doesn't always match it exactly particularly if old.