[bulletfab]

I have Mazak QT10 m/c and I can not get the mill spindle to work. It was down for years before I bought the machine. First the “m spin” load meter was 160% all the time.

We started looking at the drive (national dv-503) and found some bad resistors and caps. Replaced some parts but am not 100% sure on the resistance values of Ro and R1 (these were highly burnt (colors missing) and they metered open.

Now the load is down to 10% but the fault LED on, and there is still no voltage going to the mill spindle.

Does any one have this drive? And can tell me Ro and R1 values? (or send me a picture)
Or is there anything else I should be looking at? Thanks for any help you can provide.

[Donatello Tam]

Is the problem solved yet? I have 2 QT10N M/C and willing to take some pictures for you. However, both are not under power and I can't guarantee the part I'm going to show you is good functioning part. Please let me know what parts and places you would like to see from my cabinet. And PM me your email address if possible.

ps: Do you still have the wiring diagram, parameter list, maintenance manual and so on? I'm looking for them. Is it possible to have a hard or soft copy of manual you still have? I'm willing to pay if this could make thing easier.

[Donatello Tam]

Hello, I didn't see any National drive inside my cabinet. Is there any thing about the brush of motor? Have you clean the brush and see if the meter decreased the value?

[Donatello Tam]

Hello, I didn't see any National drive inside my cabinet. Have you look into the motor's brush. It could increase the load if dirty.