Tailstock problems on a QT200 with Smooth C control

Hi guys,

The machine has a servo controlled tailstock in W-axes.
I am programing the tailsotck and i don´t know how to move the tailstock to an especific position without pressing the piece. I write G0W100 in MDI and the tailstock does not move. I know how to move the tailstock with the M741, M742 and M743 codes, but in this work i don´t want press the piece. I need use it like a stopper, pullout the bar, press the piece manualy and then run the program.

The other problem is refered to the tailstock speed movements.
I am doing others works that requires the use of tailstock but in manual mode. For example, when you need to machine a shaft between centers.
When the door is opened and the key is in "0" position the tailstock movements are limited to 149,3 mm/min. Obviously it is a paremeters problem, but i have read the parameters list and don´t see where it is.

Can somebody help me?

Thank you!!

Part of the confusion is even tho the tailstock shows up as W on the position screen, it's controlled by the "B" Axis when used in a program. This is because W is already reserved for incremental Z movement in the lathe control system.

Next all tail stock movement is going to be in the negative direction. I would try something like

G0 G53 B-50.

That would move the tailstock 50 mm from the home position.

Tailstock parameters are mostly in the PLC. You can find the list in your electrical manual. There are usually interlocks set from the factory that don't allow you to cycle start with the tailstock at an arbitrary position (not pressed into a piece and not at home). I usually change RB parameters to turn those interlocks off for these kind of situations. I don't know if the european built machines use the same ones that the american ones use so I don't want to just give you one to change yet. Your best bet is calling your local office and talking to the applications department, they deal with this stuff all the time and can verify the right parameter for you.

The speed with the door open is not gonna be adjustable, that's a built in safety thing.

If you can't work out how to use the tailstock as a stop you can do what we do and use a black tool mounted in one of the turrets tool holders and tell it to stop at a certain position then pull your bar out and start the cycle again. As for speed limited to 149 as above its a safety thing while the door is open and can't be changed. Short of making your own door interlock key to stick in the interlock while you have the door open I don't think there is any other way around it.

Hi guys , thank you very much for your responses.

CNC Hacker, you are right. Today i have tried to move the tailstock and it works perfectly.
You have given me the solution that the offial reseller in the area does not know. They are "working" in the solution, but actually they told me that it is not posible to move the tailstock...incredible but true, they are the official resellers of Mazak here.
Your help has been very important for me, thank you very much.

HdFanboy, thank you very much too. For the nature of the parts that i am doing, it is not possible to mount a parts stopper in the turret, but i am sure that in other future jobs is going to be very helpfull.

Pablocnc said:

Hi guys , thank you very much for your responses.

CNC Hacker, you are right. Today i have tried to move the tailstock and it works perfectly.
You have given me the solution that the offial reseller in the area does not know. They are "working" in the solution, but actually they told me that it is not posible to move the tailstock...incredible but true, they are the official resellers of Mazak here.
Your help has been very important for me, thank you very much.

HdFanboy, thank you very much too. For the nature of the parts that i am doing, it is not possible to mount a parts stopper in the turret, but i am sure that in other future jobs is going to be very helpfull.

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Glad it worked out. That's the problem with machine distributors, it can be a crapshoot on support. If there is a local Mazak technology center in Spain that would be better to use for these situations.