Need Help!- Axis going the wrong way!!

[aadonline]

Hi Guys,

Just bought a used Leadwell LTC30CP CNC Lathe with Fanuc 0TC control. Got the power hooked up. Spindle turns the right direction. Z axis moves the right direction but the X axis is moving in the opposite direction. The machine home'd out normal. Everything looks fine except the X axis + direction the turret moves towards the spindle.

Is there a parameter that I should change or wiring?????

Any help would be greatly appreciated.

Thanks.

[g-codeguy]

How old is the machine? Some older lathes were programmed with X- where we would now program X+. I don't know much about maintenance, but seem to recall that you need to make a change in the ladder if that is the case. Our first couple of Moris were set up that way.

[aadonline]

Hi,

Thanks for the reply. The machine is 1998.

I found out that the jog and rapid moves the right way. But just the MPG (hand wheel) Turns the other way.

Not sure what it is.....

[botha.y]

I think you just inverted A and A' connections (or B and B', or both don't remember exactly). Check it out, should be easy to invert back. Cheers.

[ROBBY 68]

Hi
Yes, inside MPG check wiring
It works with 5VDC and It should be generating pulses backwards.
Correct wires. Positive pulses Up move / negative down movement.
Robby

[aadonline]

Thanks for the reply.

The attached picture is what I got.

Now Should I swap A & B or is there anything else that I should try.

[tc429]

yes, swapping a/b will reverse the output direction- but is z axis backwards too?
swapping a/b will reverse MPG direction on both axes.

[aadonline]

The Z axis is not backwards. Only the X axis. So is there a parameter that needs to be changed.

Thanks

[botha.y]

You've got to be more clear. Does your X goes reverse in jog and in automatic mode as well, or only with your MPG?

Cheers.

[tc429]

look at the machine position screen that shows abs/rel/machine...move the slide in the direction you want to be positive, watch the 'machine' position...if its going more negative, your servo is reversed, look in your 8200 parameters for one thats either 111 or -111... that positive111 or negative111 sets motor rotation direction.

IF YOU SWAP ROTATION you will probably also need to flip parameter ZMX, I forget where it is, somewhere on the first couple pages though... you will also need to reset your stroke limits at 700 and 704 as they will need swapped with each other- but you will probably have to 9 it out to home it the first time. the ZMX bit parameter selects decel direction for homing. Grid offset(508) will need adjusted also, or home may jump. if ZMX is wrong, machine will move to decel switch, then move back towards spindle and stop at home...it should normally move away from spindle, hit the switch, slow down, release the switch, the stop at next grid pulse.

theres a lot of stuff going on here that needs to be right, my biggest worry is why is it backwards? seems very highly unlikely that servo rotation is wrong...only times ive seen 'accidental' reversals was if someone typed in parameters for memory recovery, and didnt see the negative sign before the 111.

when you boot up the machine, does the absolute and relative screen read zero, or does it match the 'machine' position? wondering if its just got abs encoders and the servo was uncoupled during shipping or something goofy like that

if you want to try swapping parameters around, be sure you back it up first, at least write everything down before changing anything...worst case you can always put it back, but you may have to 9 out the overtravels till its rehomed again...keep rapid override low just in case

[aadonline]

Ok to make things clear....

- The Z axis is going the right way at JOG/RAPID and MPG.

- The X axis is moving the wrong way. (X+ goes south and X- goes north)

- At home position everything reads 0.0000

- IF I move X towards negative (South) The Position reading goes positive.

- When I turn off and ON the machine the ABS and REL screen read zero

I dont have a fanuc parameter manual. But I do have the parameter list form the electrical manual of the machine.

I did find that parameter 8122 in the list is 111 but the machine has -111.

Also 700 in the list is 5000 but the machine has 540000
and 704 in the list is -540000 but the machine has -5000

Not sure what these parameter means.

[tc429]

sure looks like it was intentionally reversed... did it have a weird turret that cut past center? odd

its up to you, but I would home it up, change the parameters (it will give a 000 alarm, just means you will have to cycle power after changing) and see whats up.

you should be able to find a parameter manual .pdf online- search for a '0T maintenance manual'