2D Contour Linearizing an arc??

[neurosis]

I am having an issue with a contour. There are no splines in this contour at all. It seems to force the arc to linear movements when posting. If I back plot the path it does not show these linear movements. It posts all arcs. I cant figure out whats going on and am hoping that I am just missing something simple.

 

Any suggestions?

 

I have tried to run simplify on this contour and it does nothing (no splines).

[Jmick]

There was a bug @ one time that made linearized lines @ the bottom of a ramped contour. Meaning it would post out arcs until it reached the final z depth then it would turn into lines on its final pass. If you are doing a ramped contour also make sure linearize helix is unchecked

[Hardmill]

You sure your filter is on ??

 

 

PEACE

[robh]

having the same problem here, everything looks good, code posts as arcs, but halfway thru the arc I get a line move on the part, don't know if the lead in/out, cutter comp, aicc, machine problems or what, but it's driving me nuts.

[Todd Tracey from Fastech]

On the parameter page, do you have linearize arcs selected? Bottom right corner and easy to overlook

[Joe788]

If you backplot and save the toolpath as geometry, and then analyze that, is it an arc or a spline?

[neurosis]

quote:

---

You sure your filter is on ??

 

 

PEACE [big Grin]

---

Yea. Ive tried it on, off, every combination of tolerances. Nothing worked.

 

quote:

---

On the parameter page, do you have linearize arcs selected? Bottom right corner and easy to overlook

---

I looked for the "linearize arcs" check but couldnt find it. This is a contour that has several arcs cw and ccw. All of the arcs post properly (with arc moves) except for one.

 

This is just a simple 2d contour with no z movement at all.

[Joe788]

Just throwing this out there...have you tried futzing with the Roll Cutter Around Corners drop down in the Cut Parameters page?

 

Did you get a chance to try my first suggestion about analyzing the backplotted/saved geometry?

[BrianCNC]

I have had this problem off and on since X3. Some arcs are fine and some are linearized. If I remember correctly setting the NC precision to .00001 fixed this problem for me.

 

Control def--Tolerances--NC Precision.

[neurosis]

Joe, I havent had a chance to try it yet. I'll give it a look when i get to work in the morning.

 

Brian, Thanks for the suggestion, i'll try that as well.

 

The thing that sucks about this linearization, is that it cant be tightened up with the filter. I tried to set it super tight and it did the exact same thing. This arc has a 32 finish call out so this is completely unacceptable.

[BernieT]

Does 'Combine Views' change the view # of the problem arc ??

 

If it does, that might fix your problem.

[neurosis]

Combine views did not work.

 

Joe, the backplot geometry saves as an arc, not linear.

[neurosis]

Brian,

 

That seemed to have fixed the problem. I hope that I can remember this for future reference if I have this problem again.

 

I also was able to fix the issue by deleting the arc and re-creating it. I have a feeling that the arc ends were not intersecting perfectly at its tangents but were inside of the chaining tolerance?? Just speculating here.

[gcode]

I had an issue like this recently.

5 identical circles in a bolt circle type pattern.

I was roughing them with 5 identical 2D high speed pocket toolpaths.

4 posted as arcs, 1 posted as tiny G01 moves.

I sent it in to QC and they decided it was an MP.dll bug. The misbehaving pocket backplot as

arcs and the NCI output was arcs, but the gcode was lines.

 

If you can replicate this, you should send it in.