Sodick precision problem

[Stiga]

Hello

I work (or try to...) with a Sodick A535 for about 1 year. Lately I´ve been having some problems doing holes. Imagine that I want do an 8mm calibrated hole. Right now , the machine makes an oval hole, with +- 8.04 in X , and 8.00 (correct) in Y.

Knowing that the guides are almost new (600 hrs +-) , do you have any guess on what seems to be the problem ?

Thank you

[Ario_b]

I don't know your wire EDM machine but your problem can be all CNC machines problem if you have ball screw backlash on your X axis. This can be critical if your machine use rotary shaft encoder or stepper motors.
You can use a dial gauge mounted to your machine table and step jog on X in (+) and (-) direction to measure your X axis backlash.
another source of this error can be step loss of your motor drive . if possible swap your X and Y motor drives and test the machine.

[Stiga]

I don't know your wire EDM machine but your problem can be all CNC machines problem if you have ball screw backlash on your X axis. This can be critical if your machine use rotary shaft encoder or stepper motors.
You can use a dial gauge mounted to your machine table and step jog on X in (+) and (-) direction to measure your X axis backlash.
another source of this error can be step loss of your motor drive . if possible swap your X and Y motor drives and test the machine.

Hello and thank you for replying. Well , I´ve spoken to some people and they told me about backlash (i´ve tried it, not the problem) and about the ballsrew wear and also the encoders.

Yesterday, I made some tests. The machine was working just fine I first tried the backlash test, and all was good. THEN I used G81 X and Y (didn´t use it for some weeks) and made 1 square and 2 holes , all ok... Do you think that G81 was vital ??

Best regards

[Ario_b]

Hello
I wanted to suggest you to swap motors drives but you tell that your problem has fixed.
As I mentioned on my first post I am not familiar with Sodick So I don't know the function of G81 code in your machine.
I hope your machine problem have fixed permanently.

[Ario_b]

Hi
Today I visited a friend who is Sodick expert and I said about your problem to him. He said Sodick wire guides are 2 parts that are closed by small pneumatic
jack . Some times small particles of brass (from wearing of wire) between two parts of guide don't let the guide close completely and wire can move in small space between two guide parts. This small space between two parts is parallel to X axis that only let the wire move in X direction. So a not clean guide can cause this problem in your machine .

[irontomflint]

I agree that the most likely problem is the upper guides are not completely closing.

I have worked on Sodicks for many years, and if you don't do periodic maintenance to keep the upper guide area clean this will happen again. Your best friends will be Q-Tips in this area to get it clean and dirt free.

Good luck, I hope this solves your problem.