[jogtx16v]

hello

I work on a old ''pratt fanuc tape drill 1989'' with 0M control.

I need help to repair it .

I can't home the Y axis and when I move the axis in (+) or (-) I don't hit the overtravel alarm of the limit switchs.

it appears : servo overload Y axis at the two extremity of the table

[Mr Bonavita]

1- HAVE YOU TRIED PRESSING "P" "CANCEL" AT START UP?
2- OR MAYBE YOU CHANGE THE STROKE LIMIT PARAMETERS ?
IF NOT TRY THE FIRST.

[jogtx16v]

I have tried to press both P & Cancel at startup but it do nothing.

i have alarm Y need zero return all time at start up , and I can't do zero return .
it goes over the limit switch i think. (alarm servo ovorload)

thank for your help

[botha.y]

Are you sure you are not doing a collision with your Y axis? Because if you get an overload message only at the end of travel in both directions for your Y, that would likely be that the Y axis cannot mechanically move further, which is why it would give you a servo overload alarm. Check your hardware overtravel switches, and also check your reference switch, look at the plc diagnose and see if the reference switch triggers a signal (it will be in the X's diagnose signals, should be easy enough to find if the switch actually works, I think it is a bit in X17 for 2nd axis).

Cheers.

[jogtx16v]

yes the cnc have a collision in Y axis about 2 years and we not used this machine before this week.

** but I can move the Y axis in JOG easily **

sorry for my English

[botha.y]

I didn't mean that the Y-axis does not move because of a collision that happens. I was asking if your Y-axis gets an overload at the end of travel sides. Because if it does, then it is because your Y-axis cannot move further mechanically. Either your limit switches are not working or they are placed to much out of the way. And check bit X17.5 for your Y-axis reference return switch (assuming Y is your second axis, as it should be).

Cheers.

[jogtx16v]

where is the bit x17.5 ? this is in parameter bit # 0017 ?

[botha.y]

Nope, that's in your diagnosis menu. You click on param hard key, then on diagn soft key.

[jogtx16v]

im not sure but this is at dignostic no. 0017 -10100000-

im at the right place ?

thank !

[botha.y]

Yes. Now you have 10100000, so the second 1 is your X17.5 signal. (3rd from left, 6th from right) 1(X17.7)0(X17.6)1(X17.5)0(X17.4)0(X17.3)0(X17.2)0( X17.1)0(X17.0).
Now press your reference switch or travel over it and check if the signal X17.5 changes to 0 when pressed. If it does, then the switch and your connection is correct.

[jogtx16v]

ok ! now i understand

I did the test and the bit stay to 1 all the travel time .

I will try to press it with screw driver next time.

[hrh]

Do you get alm 300 or similar Y axis needs zrn?

If so, then the machine is probably fitted with absolute encoders.

[jogtx16v]

Do you get alm 300 or similar Y axis needs zrn?

If so, then the machine is probably fitted with absolute encoders.

YES ALARM 320

can you explain me more about that ?

I know the machine was upgraded in the past, ex: added rigid tapping , and x,y,z interpolation was added also.

another fact, before starting the machine for the first time after two year sitting, I changed the cover of X and Z servo motor. this procedure include to disconnect the servomotor wiring plug.

when i started the milling after that couple of error code, ex: battery axis zero and need zero return . For the Z axis , I only restart the machine and I did a zero return . after that Z axis was ok , but not the y axis .

thank

[hrh]

Ok.

Check parameter 021; should be 00000111 indicating that x,y,z are using absolute encoders.

Easiest is to move the Y-axis with the MPG in HANDLE mode as close as possible to where reference position should be. It is important to rotate the motor more than 2 times, therefore move in the minus direction first and then back to the desired position in the plus direction.

Then set parameter 022 to 00000111 to indicate the absolute encoder has reached reference position. Power OFF then ON again.

[jogtx16v]

ok its absolute encoder !

I found the problem . Y limit switch was jammed.

The Y home position now work !

but, I don't have the overtravel alarm in Y-

I have only one switch in Y and one in X . the second switch of these axis are disconnected. I assume this is normal with absolute encoder . what do you think about that

thank a lot

[hrh]

The switch is possibly used for emergency stop and there are two cams / dogs on the sliding part of the Y-axis if the switch is in a fixed position.
The cams / dogs will be on the base or fixed part of the machine if the switch is moving with the Y-axis.

You should at least get stored stroke overtravel alarms for + and - directions but if the parameters are set to maximum -99999999 or 99999999 then the alarms (alarm +520 or -521 overtravel) won't occur on standard sized machines.

Check the stroke parameters 701 and 705

[jogtx16v]

thank you very much , i will try this tomorrow .