[Hermle UWF851]

I bought a used Puma 6s With a Mits Meldas controller and I cannot thread. Comes up with an alarm that says the spindle is not on. Works only with dry run. Found out the tach is not reading. Also, the rpms are actually 1/3 what is programmed. Example, if you program 1000, the display shows "S1 303" and below that shows "( 0)". The 303 is verified with an independent tach check. It had an 8" chuck on it that can only rev 1900 rpms. I'm thinking the previous owner changed some parameters that lied to the gear ratio so if you program in 6000 it will actually rev 2000. Then disabled the tach so it wouldn't alarm out because the rpms don't match. Why not just change the max permitted rpm? I don't know. Is this even possible or am I making a conspiracy theory? I talked first with Daewoo, they referred me to Mits. Mits worked with me over the phone and eventually gave up and said I need a new spindle driver. I can't believe that. I'm asking fellow machinists first before I send in my driver. Thanks for any help.

Frank

[sixstring]

You Might Want to Check The Spindle Encoder , Which Is Usually Belt Driven From The Main Spindle To A Smaller Pulley That Is Mounted To The Encoder.

[Hermle UWF851]

Thanks. The belt is fine. Infact, I can unplug the encoder from the driver and it works the same. This makes me think it is bypassed. I sent out for a new spindle driver. In fact, it should be here today. I'll post my findings.

[Hermle UWF851]

It wasn't the spindle driver as Mits said. I ended up talking to a very good Mits guy named Mo. After about an hour of disscussion and telling him the problem from the start, he said the board that the encoder plugs into was the problem. It has a name but don't know what it is right now. Anyway, the next day it arrived and it worked. Everyone I talked to really tried to help but it is difficult over the phone. Three weeks with the wrong two people talking is the same as one hour with the right combination of two. I would absolutely hate to have there job of fixing problems over the phone.