Mounting rotary 4th axis on a sine plate.

[Jeremy Grigsby]

I have a mill with a rotary table aligned with the x axis. I have some round segment parts i am doing that are mounted to the rotary. Most of the work on the part is just work that is perpendicular to the outside diameter of the part. There are a couple holes that need to be drilled @ 2.75 degrees off the z axis. Our plan is to mount the rotary on a sine plate at 2.75 degrees, still aligned with the x axis. The yz 0 point is the centerline rotation of the rotary axis. The part we are cutting is a bigger diameter than the fixture it is mounted on, so the centerline is not the same as the rotary. All that information given(I hope I've answered any questions up to this point) Can I tell mastercam that my rotary is at a 2.75deg angle so the holes that i program will rotate and move x,y,z to cut in the right spot? If this part were mounted out at it's finished diameter, it would just be a y0. location (at the right spot in x) but since it has a different centerline, this may not be the case. We are on Mcamx6 mu3 with mill level 3 and 5 axis.

[Jeremy Grigsby]

Any ideas?

[John Summers]

I couldn't quite make sense of the thumbnails, but the general method is this, when a rotary table is mounted on a sine plate: Rotate the hole axis with the rotary table until it is perpendicular to the hinge axis of the rotary table, then tilt the rotary table until the hole axis is vertical.

[mkd]

^^^Yes, rotating the geometry is probably a less risky way for a newbie^^^

 

alternately one could just make coordinate systems for each machining feature.

[Rotary Ninja]

I have ran into this a few times. When you setup the rotary on a sine plate Mastercam thinks you are doing 5-axis work. Is that the problem you are having? If you can upload the file you might get better help.

[Jeremy Grigsby]

Look guys, I understand work planes. I am just wondering since the rotary table would be rotating on an axis that is tilted in z, will it post out appropriately? The part is not out at the diameter it is drawn in. The holes are equidistant from the end face of the parts, but different distances from y centerline. So I believe rotating on a tilt will make xyza different for each hole. Now that I think of it, I dont think there is any way to put the holes in so the are perpendicular because of the part being mounted at a lower diameter. I think I would need a tilt head to acheieve the right angle. I'm attaching a file if any of you want to take a look. The holes point to a different centerline than the rotary axis.

ANGLED HOLES.MCX-6

[John Summers]

You need to draw the rotary table and the sine plate accurately (the way they will actually be on the machine), then you can find the hole positions with Mastercam. When you rotate the part with the rotary table, the sine plate is FLAT. You rotate the part until the tool axis is perpendicular to the sine plate hinge axis, THEN tilt the sine plate. If you have both a sine plate and a rotary table, you don't need a tilt head. The way you draw the part, rotary table, and sine plate is important. In Mastercam, you will rotate the part about the rotary table axis, then tilt it about the sine plate hinge. The distance between the axes must be the same in the drawing as in the actual setup. Add the rotary table and sine plate to the drawing, and we can help you some more. You are also going to have to choose some point as the setup origin (0,0,0).