Best way of setting Y and Z = 0 on 4th axis job?

[goor]

Hi,

I'm preparing jobs for 4 axis simultaneous machining on my XYZ 1010 VMC machine.

I am using SolidCAM for my CAM, and am setting my MAC1, POS 1 at the centre of the 4th axis rotation. So my Y and Z axes are in the centre of the 4th axis spindle.

Until now I have set this on my machine by just scraping the top and side my raw material (a round bar held in my 4th axis chuck) and setting the offset using the diameter of the bar. Obviously this is a reasonable way of doing this, but it allows for slight error.

What would you recommend as an accurate and quick way of setting Y and Z to be at the centre of the 4th axis?

One good way of doing this is by using a precision bar, and a DTI to measure deflections on the top and side. But this is time consuming. I do have a probe tool that I use to get accurate positions.

Is there a better way? Are there any gizmos out there to help in this?

Any advice would be great.

Thanks,

Goor

[fanchchina]

Dear Friend, so have you consider to fix the 4th rotation axis on the X axis please?

[RICHARD ZASTROW]

In my corner of the world, the table of a VMC moves in X & Y axis. The spindle moves vertically in Z axis.

The precision bar method you mentioned works fine. Another is to place a pair of ACCURATE angle plates against the bar. One in front, one in back. Tram between the surfaces of the angle plates for "0". The DTI on the precision bar is probably faster though.

Dick Z

[laka]

Why don't you write your values down somewhere so you don't need to get Y, Z for each new job? Our machines use G54-G59, and we dedicate G59 for the 4th axis. Even if we remove it and re-install it all we need to get is our X.

[DareBee]

Interesting - I use G59 as our 4th axis fixture as well.
I usually pick up both sides of the part and offset 1/2.
It is important to indicate the part to be running concentric and parallel to the axis before hand (just like in a lathe).

[Fixittt]

in my world of desktop cnc /jewelry wax cutting. I take a piece of sacrificial wax (MDF or the alike will work) I draw me a simple square say 6 to 10 mm thick. I cut these things and measure the thickness after every cut. Lower Z until your part is the exact thickness you drew it to. Zero Z then lower it half the thickness you made your part. Re zero Z. as for Y center. Zero y work coordinates. I drill a small hole where I think Y center will be. Rotate a 180 and see if the bit goes back into the hole. If not, move Y until it does. Look at the DRO, write the number down with the + or- in front of the number. Go back to y zero (g0 y0) which is the location you drilled the hole at. Then move Y half the distance that you wrote down. Re zero y then move X over and drill again until you can drill a hole rotate A and the bit goes back inside the hole you drilled.