Mazak

[Joels]

Hello, If i could ask i need help with our Mazak Integrex 300S. The problem i am having is i have a piece of round aluminum stock in head #1 and i mill 2 flats say about 1.500 inches thick. I then drill through the aluminum then use a 3/8 diameter endmill to circle interpolate a hole through the flattened stock. so far everything is good. I then put a indicator in the milling head and position it over the center of the hole and check the runout. The runout is maybe .0001. Good so far.

Now i rotate the spindle to 180 degrees and check the hole runout and it is a couple of thousands.

 

Mazak service and i have been fighting this for a week. Mazak service has checked everything and it is running straight. any ideas what could be causing this?

[chris m]

You are mixing and matching terminology and I am confused. Are you saying that you're holding the part in the left (main) spindle and interpolating a hole through it? Through it how? in the face of the part, in the side of the part? On center, off center, straight, angled? A picture of the part or a little sketch would be helpful here.

 

I am going to make the assumption that you are putting the hole in from the side at 90 degrees from the spindle centerline and that when you rotate the main spindle 180 to get to the other side of the part it sweeps differently than when you're on "top?" If you sweep the top and bottom of the hole on the first side and its good, but when you swing the spindle around and do the same it is bad, I would say you have a serious main spindle issue.

 

This, of course, assumes that you have inspected the part and that the bore is actually round and straight...

[Joels]

Your assumptions were correct. I am machining the hole with C AXIS at 0 deg and the milling head at 90 Deg with the positioning of the milling head at say Z .5 and y at Zero. I am drilling a hole at this position and using a end mill to circle interpolate a larger hole. I have not put the finished hole on a CMM but when i use a plug gage the hole has the characteristics of being round to a couple of .0001. This is almost a brand new machine we started using it in March of this year.

We have checked everything and it looks good. The tools i am using are not the best so we are starting to look that way now. I am going to do some testing on the tools today but we have seen this issue on 2 different style parts.

A little history. I tried to do a spindle transfer to machine the parts i need but the tolerance of .0005 cylindricity between bores was not working. it was running out a couple of thousands. For a short term fix (to get the parts done) i decided to machine the complete part on the main spindle by rotating the main spindle 180 degrees to machine both ends figuring that both ends would line up but it doesnt. it runs out from .001 to .005. this is just from rotating the spindle 180 deg.

Thats how we got to this point and we cant figure out why this is happening. I need to make parts and the machine has been down for a week.

[Mic6]

Trying boring the hole and see what you get

[Joe788]

It sounds like your Y axis offset is not on center.

[Joels]

The problem has been solved. The Mazak service person re-aligned the Y AXIS and it is good now. Thank you to everybody who replied.