Need Help!- Trouble with lathe turret

[Joe Miranda]

I have a Cent IV controller on my lathe with an 8 station pragattie turret. Today I screwed up and had a boring bar that stuck through the end of the tool holder too far and when the turret went to index it jammed the boring bar against the side of the turret. But now it won't index. I checked all the fuses I could find and there are no blown fuses. When I give it an M06 command you can here something click in the cabinet and the turret hums but no movement. Any ideas on where to start?

Joe

[mholden]

take the little end cap off the motor there is a 10 or 12 mm hex that you can put a socket on and index the turret buy hand if you can turn it ok then in MDI do a M20 this should index to the next pocket.

[Joe Miranda]

Ok, I took the end cap off and indexed the turret by hand. I tried an M20 and nothing happened. I tried and MDI tool change and again nothing. If I try a manual tool change and try indexing the turret manually from the back I can feel some resistance and some humming noise like it is trying to do something but nothing happens. What next?
Joe

[mholden]

Are you sure you have all 3 phases it sounds like you lost one.
double check for from phase to phase to phase on the top side of the relay you should have 220v across all 3. if you have it there then check at the motor when it is trying to turn you need all 3 phases.

[Joe Miranda]

Originally Posted by mholden Are you sure you have all 3 phases it sounds like you lost one. double check for from phase to phase to phase on the top side of the relay you should have 220v across all 3. if you have it there then check at the motor when it is trying to turn you need all 3 phases.

Can you tell me where this relay would be located? Also, the turret will occasionally index a couple of positions and then just stops and you can hear a humming until I hit e-stop. Also, I use a phase converter. I get about 118volts from two of the legs to ground and the wild leg is between 230 and 260volts to ground. Between the two balanced legs I get around 234v and from either of those two to the wild leg I get around 260v. That's where the lines come in at the main switch. I don't know how to check at the motor. I guess I can give it a try.

OK - I checked the voltage at the motor and it is the same as at the main disconnect switch; 118v to ground on two of the legs and about 230-260v to ground on the wild leg with 234v between the two balanced legs and between 260-271v from either of those two to the wild leg.

Please help. Thanks
Joe

[mholden]

If you move the turret with a wrench ok then i would say the motor is bad if there are some hard spots when you are turning it then you have damaged something in the turret like a gear or bent shaft

[Farmers Machine]

Joe cant help with the crash, but when I had my ML 20 upgraded with Pragati 100 turret we mounted a 3 HP AC motor drive that has 220 volts single phase input and outputs 220 volt balanced 3 phase to the turret. The CNC control tells the motor drive when to go and what direction to go. 2 years and no trouble. I jamed a boring bar like you and had an instant drive overload fault that stopped the turret before any damage could occur. The amps are programmable in the drive and the response time is in miliseconds. Got the drive from Automation Direct .com. I have converted all of my band saws and drill presses with 3 phase motors to this type of drive to run in my single phase shop. I hope your problem is simple electrical fuse or breaker tripped but if not Bob at Milltronics parts can have you up and running in a jiffy! Good Luck the Farmer

[Joe Miranda]

Originally Posted by mholden If you move the turret with a wrench ok then i would say the motor is bad if there are some hard spots when you are turning it then you have damaged something in the turret like a gear or bent shaft

mh
I have been told that when you index the turret manually and you notice a different feel as you rotate it that it is because it goes throug ha a clamp/unclamp sequence that uses a spring loaded plate to differentiate between the positions so I don't think that anything is bent. Besides that, it wasn't that kind of an accident. The turret only indexed probably about a degree before it encountered the obstruction. But I am not sure how long it was trying to complete the tool change before I hit e-stop. I did take the motor off and it does smell kind of burnt. Also, I did an ohms reading between the legs at the motor and one of the legs shows higher resistance (or whatever ohms measures) than the other tow. Does that mean the motor is bad?
Joe

[Joe Miranda]

Originally Posted by Farmers Machine Joe cant help with the crash, but when I had my ML 20 upgraded with Pragati 100 turret we mounted a 3 HP AC motor drive that has 220 volts single phase input and outputs 220 volt balanced 3 phase to the turret. The CNC control tells the motor drive when to go and what direction to go. 2 years and no trouble. I jamed a boring bar like you and had an instant drive overload fault that stopped the turret before any damage could occur. The amps are programmable in the drive and the response time is in miliseconds. Got the drive from Automation Direct .com. I have converted all of my band saws and drill presses with 3 phase motors to this type of drive to run in my single phase shop. I hope your problem is simple electrical fuse or breaker tripped but if not Bob at Milltronics parts can have you up and running in a jiffy! Good Luck the Farmer

farmer
That sounds like a pretty cool solution but I think that is way beyond my capabilities. I know where to hook the leads up to the machine and that is about it. What you did sounds ovewhelming to me.

Bob at Milltronics is the go-to guy? Should I ask for him by name or is he the only one in that dept?

Joe

[jpawelk]

Bob works for Milltronics parts. You may contact him for any parts questions or orders. If you have any service questions and/or concerns please contact Milltronics service department @ 952.442.1401.

[Joe Miranda]

OK. I pulled the motor and took it to a motor shop. They verified that the motor was burned up. They rewound it and replaced some coil in it. I put the turret back on and gave it a tool change command and still nothing. I checked the leads at the motor and I am not getting power. Before I pulled the motor I had power at the motor. What could have happened and where should I look next?
Joe

[jpawelk]

Joe,
I am certain that if the motor was shorted it probably took out the fuses that are associated with the turret power. Check the fuses.