Low Range Troubles-V2XX

[Big Daddy]

I’ve spent thousands building a super trick V2XT. New main computer, new sensorless vector spindle controller. 6,200 rpm direct dive AC spindle plus I put in a urethane buffer in the gear box spline joint to eliminate the historicist for rigid tapping capability (with floating holders) also eliminating the annoying rattles up stairs. Reworked spindle pre-load and put in 4 new spindle main bearings for enhanced rigidity and better surface finishes. Plus much more. But after I finally got the mill finished & the drives tuned I found a problem with the machine in that it will not run a program when the spindle selector is in the low range. Any Ideas? Big Daddy

[machintek]

The original machine used piggy back contacts to see that the spindle contactor was pulled in, meaning the spindle was running. This was true for low and high gear. For the low/high gear there was a prox switch that would tell the control what range it was in. Lastly there was a speed feed back pot which was a linear taper potentiometer attached to the front of the head. Based upon the relative position of the speed change gear/air motor, you had a approximate spindle speed feed back.
If the spindle was not running, it would not do a feedrate.
Since this is not a stock machine, you need to see what the control lacks.

George

[Big Daddy]

Thanx for your response George. Yes the proxy switch is in-tacked and working fine. Yes the spindle fires up to speed that’s programmed. But that’s it, No it won’t run any feather in the program. No alarms/ No Fault messages just died in its tracks and looking pretty stupid.

[Big Daddy]

Here is some more I didn’t touch on last night George, the linear taper potentiometer and the whole air speed controller assembly has been removed & disabled. The only thing there is just an empty shell to close up the hole. But I guess it’s still possible that there might be a switch still open somewhere on maybe a jumper that should be put in place somewhere that could have been overlooked. Or I'm still not receiving a signal from the spindle controller that the cycle is complete back in the mill. It kinda sounds like a signal
Is definitely crossed some where. Ruling out stuff; the range selector lever & proximity switch are at least work fine other wise the spindle would never start up at all. And I know the spindle controller is receiving & sending its signal or the spindle would never go the programmed rpm…..

[machintek]

If you have an AUF board and a BMDC board look at JP3, pins 1b and 2B, which have wires 25 and 27. These go to the spindle forward and reverse contactors piggy back aux contacts and tell the control the spindle is turning. No continuity here, and the machine will not feed.
Sheet 2 of 2, page 4-8, dwg 1943101, about line 80, of the maintenance manual.

George

G

[Big Daddy]

Thanks George I'll do that at my first chance. This will give me a place to start. Good call.

[Big Daddy]

Well George, this isn't going to be so easy. Funning thing is when I went to my maintenance manual that chapter stops at page 4-7 table 4-2 the fuse chart. Can you help?

[machintek]

You never said if you have a FMDC or a BMDC. Big difference.

George

[Big Daddy]

I have a BMDC. It’s been checked out in Collaboration with EMI & done by one of the best Bridgeport Tec’s on the west coast. Also I have some experimental Bridgeport software running that I purchased from EMI. They bought the rights from Bridgeport during the bankruptcy. The software affects the way the machine runs. And was never released to the pubic.

[Big Daddy]

George I got to thinking, “I wonder if George is referring to the wiring schematics’ that came in the machine's cabinet???” Low and behold,,, there they are!!! Again thanx for your help. Big D