Multiaxis gurus out there?

[WingNutz]

To put it in simple terms, we are trying to do a lathe part on the mill. With a 4th axis and a ball end mill, we want to rotate part 360° then step over in X axis then repeat. We got Mastercam to backplot correctly, but the post is spitting out un-needed B moves about every 2 degrees. Any help would be appreciated.

[tstom]

What tool path are you using and do you have the 4th axis button checked
Helps to post a file

[Superman]

We got Mastercam to backplot correctly

Don't rely on backplot to be correct, there's too many steps between the graphic display and the NC-code that goes into the machine

I am assuming you are doing a sufacing operation and your WCS and other planes are correct

Your machine is probably doing the correct operation, it may just need refining, your "cut tolerance" and / or "filter settings" need adjusting.

"cut tolerance" = how far can the tool move off or into the part
"filter" = how far can points be adjusted to make a straight line or an arc

tstom may also be correct as the rotaty axis does come into play

I suggest keep what you have or make it really coarse, for positioning the tool and replace all the small B movements for 1 revolution ( G01 B360. )
or make a sub-macro with small retract
( goto position, run sub, goto position, run sub,....,big retract)

I may be on the wrong track, but is it outputting only B moves on each block ?
if yes, what is the problem ? Have you tried to run it ?

It may output many points in case the part centre is not the spin centre

[WingNutz]

Thanks for the input. First, we haven't tried to run it yet and yes they are "B" moves by themselves, but we are limited on memory space which is why I don't need the excessive b moves. The sub-macro is our last resort, but not out of the question. We are trying the multiaxis toolpath and the rotation axis is correct. Our cut tolerance was at .001 but we were getting z moves that ranged about .001 so we changed it to .0005 and the z moves went away. I thought maybe the post was limiting the nc file from doing a complete rev with a formula, but I can't find it.

[tstom]

Maybe I should have first asked is you 4th axis A or B I assumed (bad thing)
that this is a 5 axis machine and A is 4th B is 5th

If you are just getting too much code the cut tolerance and filter should allow you to cut it down but it can affect the finish

Another possible approach if this isn't a surface is axis substitution and a 2d toolpath

It's always easier to help if we can see what you're trying to do

[Switcher]

Originally Posted by WingNutz To put it in simple terms, we are trying to do a lathe part on the mill. With a 4th axis and a ball end mill, we want to rotate part 360° then step over in X axis then repeat. We got Mastercam to backplot correctly, but the post is spitting out un-needed B moves about every 2 degrees. Any help would be appreciated.

I don't run Mastercam, is it possible to trick mastercam by leaving a B-axis out of the setup. In other words If Mastercam only sees a "X,Y,Z,A-axis" then it shouldn't output anything in a B-axis move, that would only work If the part your cutting never needs the B-axis thru the entire run/job.

Just an idea.

.

[tstom]

Mastercam has buttons to use 4 or 5 axis on all 5 axis toolpaths

[Steve Arteman]

wing,
Post your part we can see if I can help .
steve
steve@cad2cam.net
www.cad2cam.net

[WingNutz]

I am somewhat new here and never posted a file on here for review. Is there a thread that explains it? Thanks. And when I finally do figure it out, which files do you guys want for reviewing? Just the X3 file, or the zip2go file?

[tstom]

just the X3

I usually save the file to my desktop then right click/send to/compressed zip folder then at the bottom of the reply page click "manage attachments" then the browse button and navigate to the .zip file and attach there is a chart as to how large of a file you can attach