[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'

[aadonline]

OK I changed the parameters. Everything moves the right direction. Except when I try to home it, It goes the opposite.

[aadonline]

I am still missing something...

I flipped the ZMX parameter (003) And it still goes the opposite direction to home. Also when I press the JOG/RAPID it goes the opposite and the Position shows the right way.....(If I press X+ the position and turret moves in X-) :drowning:

The following is a program left by the previous owner...Have no clue what they were doing..

O6591(BEVEL HEAD O.D.)
N0001G00T0101
G50S800
G96S600M04
X-14.5
Z0.1
M08
X-14.15
G01Z-0.250F0.01
U-0.05
G00Z0.1
X-13.950
G01Z-0.250
U-0.05
G00Z0.0
G01X-12.0F0.012
Z0.1
G00X-13.725
G01Z0.0
X-13.825Z-0.1
Z-0.25
U-0.1M09
G00Z0.1
X-13.625
G01Z0.0
X-13.825Z-0.15
U-0.1
G00X-14.5
Z10.0
M05
T0100
M01
N0002G00T0404
G50S800
G96S600M03
X-3.0
Z0.2
M08
G01Z-0.55F0.012
U0.05
G00Z0.2
X-3.2
G01Z-0.55
U0.05
G00Z0.2
X-3.4
G01Z-0.55
U0.05
G00Z0.2
X-3.6
G01Z-0.55
U0.05
G00Z0.2
X-3.8
G01Z-0.55
U0.05
G00Z0.2
X-4.0
G01Z-0.55
U0.05
G00Z0.2
X-4.2
G01Z-0.55
U0.05
G00Z0.2
X-4.3
G01Z-0.55
U-0.06
Z-0.500
U0.15
G00Z0.2
X-4.4
G01Z0.0M09
X-4.3W-0.1
U0.1
G00Z15.
G00X-11.5
M05
T0400
M30

[tc429]

if you have a ladder copy, search the +x and - x coils... think they are around G96 address (diagnostic display page down to the 80/100/120 start address while jogging +/-, look for the bits that are changing- I dont have a book handy...) if say 96.0 and 96.1 are changing to '1' when jogging, bring up the ladder display and type 'g96.0' and hit 'w-search' softkey. look to see if there is a 'd' bit in that rung that switches function from a couple inputs marked 240 or 290 range- those will be the operator panel buttons(this assumes you have a fanuc op panel). a lot of lathe mfgs will add a 'd' bit there to reverse the panel buttons for right/left hand machines. to change a 'd' bit, you need mdi+key+pwe=1

if I get a book and a few minutes, I can post more info later, if not hopefully someone else will chime in

[botha.y]

Try G28Y0; I think your machine is completely lost regarding your zero see if it travels the correct direction so it sets back your machine 0 where it is supposed to be. Don't forget to change parameters 700 and 704 (X OT+ and X OT-) accordingly, set them to 999999 for the moment to adjust your reference position, then change those parameters (I assume you have hardware OTs). Cheers.

[aadonline]

The Z axis is still good.

I cant do G0G28U0. in MDI as it says X and Z axis not Home.

I found the Diag # for the jog buttons. Its 116.3 for X+ and 116.2 for X-.

I went to the Ladder page and I got upto doing a W-SEARCH for G116.2 but I didnt find any d bit in the rung. I am kinda lost here..........

[aadonline]

I found the ladder page in the manual.

Looks like G116.2 and G116.3 are swapped around. Is there a way to change them back.

Thanks.

[aadonline]

Is there a way to Home the Machine without messing around with the ladder.

Please help

Thanks.............

[botha.y]

Dude,

Does your X axis goes the wrong way ONLY in MPG or BOTH in jog and MPG?

If it was only your MPG, then get all your parameters back to what they were before you opened this thread. Then change parameter 0386 bit 0 to its reverse value (0 if was 1 and 1 if was 0). Then if your reference return goes the wrong direction, change parameter 0003 bit 0 to the reverse value (0 if was 1 and 1 if was 0)

Now if you X-axis goes in the wrong direction no-matter what, I don't remember if there was a parameter to reverse polarity of a motor for 0T. There are a few possible solutions I could think of but before you try that, check this first.

Cheers.