Mazak QT20 Fanuc Spindle issue.

**bdrotau** · 01-12-2021, 06:13 PM

Hi all.
I have a 1986 QT20N (Mazatrol CAM T2) with Fanuc model 12 (A06B-6044-H212) spindle drive.
Machine is working well for about 10-15 minutes but after that Alarm 20 NMI emergency stop and alarm 204 spindle controller malfunction is turning on.
So i have to wait for about 40-50 minutes to be able to work again about 10-15 minutes.
Is like some component is heating and i have to wait to cool down.

Any idea about this malfunction?
Or, Can somebody advise me about a AC spindle drive upgrade? Or a VFD sensor less much newer that is compatible with my machine?
I would really hate to start a so called retrofit with Chinese controller, motors and drives and give up Mazatrol.

**wippin' boy** · 01-13-2021, 09:43 AM

yes, there is a way

there is a thread in this forum about a Hitachi VFD retrofit

**_EMF_** · 01-13-2021, 12:59 PM

A temporary fix to keep you going is to open the electrical cabinet and put a fan there to cool the drive. My QT 28 does that due to a weak fan on my NC unit which causes a connection issue between my one board and the NC unit.

**bdrotau** · 01-13-2021, 11:14 PM

can you point me at that post? i have searched but no success. thanks

**wippin' boy** · 01-14-2021, 10:01 AM

i searched several things
finally just tried Mazak spindle drive and got -0- results
so
you'll need someone smarter than the PM search function
sorry
my suggestion would be to p.m. Toolcat
i would imagine he remembers the project and might even know how to search this joint