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SQT-15M turret not positioning correctly

131rally

Plastic
Joined
Dec 22, 2018
I bought this SQT-15M year ago. At first the turret located (in program from tool 1 to tool 6 for example) mostly right. And if not, it was due misbalance. Some months work and it started to jump over from correct tool. I found out the encoder was misaligned and it started working again, but for some reason the encoder started "floating". I marked the position of the core of encoder, core doesnt float, but for some reason the red led just wont be in the same position very long time. Now if it stays whole day its long time. I didnt put the casted cover in place at all, so the alignment is pretty fast to do. BUT, now it started jumping over more and more, even the encoder is positioned right. It may work one full day right, then next day hardly any tool change goes right. I even made manual programs between every tool change to make it go one tool at a time and it helped a lot. But, now it may jump over even after one step of tools, I mean it needs to change from 1 to 2 it may bounce to 3.

What is most likely the problem? I havent crashed it at all. Otherwise it works pretty fine. I would like to keep down time in minimum, what parts I should get ready for the fix? I have changed new bearings to live axle so I know how to dismantle it. All I need is to choose tool 1, mark the gearing, and then just open the bolts? And, is it possible the encoder inside floats, somehow parts loose?
 
And I answer myself to the guestion. After intensive thinking of what happens and when. I came in to conclusion the turret encoder must be the problem. Took it away and opened it. The outside gear turns some 50mm long shaft, and in the opposite end of the shaft you see around 40mm diameter disc full of holes of all forms. Sensor looks the position of the holed disc. And, its mounted with single Philips screw from the center. I could move the disc by one finger in the axle. The screw wasnt loose, but the disc moved. So, I opened it a bit, drop of glue and torqued it as tight I could and remounted all. Now everything works perfect.

If you open it, three screws around the core, three screws inside holding the electricsboard, and under it you find the problem screw. Very easy fix, except getting the encoder out the turret body which is not fun.
 
The turret jumping started again after the last post. I changed new exactly correct hydraulic oil and new filter. Also cleaned the reservoir, and it was DIRTY. There was several liters of syrap like oil... After changing oil the jumping got even worse... I noticed that if I run the turret over and over in jog mode untill the indexing motor feels warm, it stopped the jumping and worked as long the motor was warm. So, we took indexing motor out and took the hydraulic solenoids from it. We opened and cleaned the solenoids. Rexroth is for unclamp/clamp the turret, the Nachi is for running turret clockwise or anti-clockwise. Both didnt slide smoothly so we carefully polished all parts. After the polishing/cleaning all problems with turret went away. It has NEVER worked this smoothly. So, problem was caused when the Mazak turned turret, and wanted to stop turning. The solenoid was 0.1sec too slow stopping the oil flow and it went too far. Now it cuts oil flow fast and the turret stops when it should. Just for all you people who have same problems.
 
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Thanks for sharing your experience, I might find it useful, as my turret does not seat perfectly when tools change.It is not an encoder problem, propably swarf is trapped between the contact faces.
 
I have struggled with this problem a lot. And I finally got it working. So happy it works 100%.
 








 
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