Pocketing Errors..

[Rekd™]

I created a rough pocketing routine to machine a floor and some bosses.

 

I then copied the rough pocketing routine, changed the stock values to zero, (from .001 XY and .002 Z) and regenerated the operation.

 

The new operation does not generate correct finishing passes like the roughing operation does.

 

If I check Machine Outer Boundary, it will create the correct finish passes, but I do not want to machine the outer boundary.

 

Anyone else seen this? I have a sample file you can try it on if you like.

 

'Rekd

[mayday]

Rekd,

2d pocket or surface ruff pocket?

[Rekd™]

Standard 2d pocket

[Rekd™]

Download it.

[mayday]

I turned of finish outer boundry in the final 1/8 em path didnt change anything else,it seems to look ok here unless im overlooking something. just what are you seeing happen?

 

you thing to try, change your stepover amount slightly 1 way or the other. I have seen this change the finish path quite a bit. you may get what you want by doing that

 

[ 12-16-2003, 03:40 PM: Message edited by: MayDay ]

[Rekd™]

On this file I'm stepping over 49%.

 

Here's a screenie of the original pass that leaves .001 on XY and .002 on Z.. (If you've d/l'd the file, this is Operation 1: Rough -A-)

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Here's the SAME toolpath copied, the ONLY change I made is to set stock to zero on XY and Z..

 

Thanks for the imput.

 

'Rekd

[Accu-Molder]

I changed lead in/out to 5% and it worked correct I think

[mayday]

I see said the blind grammer

 

set your step over to .05, 40%

turn off outer boundry

it worked here anyway

[Eric S.]

hello Rekd

 

 

 

I think I have found you problem. Your cutter comp for the finish pass is to large to fit into the .140" slot. If you change it to say .005 arc and .005 line. it works. Oh ya for some reason I also had to turn off the "start finish pass at closest entity(got me on that one)

 

Hope this helps!

 

Eric

[Rekd™]

Thanks for the imput. I understand there are several things I can do to get it to work.

 

My questions are;

 

Why does it work on one toolpath and not on the copied one, when the ONLY difference is the stock of .001 on the sides and .002 on the floor?

 

Is it happening to anyone else?

 

I've also seen, more times than I can count, where islands get wiped out, other areas don't get cleaned up, CRC is applied to arc moves, etc etc etc.

[Rekd™]

Eric, if that were the case, then the ROUGHING op would have failed, not the FINISHING op, because there is more room, albeit only .001, on the finishing op.

 

'Rekd

[Eric S.]

But if you look closely when you rough the finish pass starts at the large opening at .06 chamfer. I think when you change the amount of material the pocket ends in a diferent spot and the start finish pass at closest entity on the lead in will now be in a slot?

[Eric S.]

quote:

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I've also seen, more times than I can count, where islands get wiped out, other areas don't get cleaned up, CRC is applied to arc moves, etc etc etc.

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I have had this problem also in the past and the lead in and out has always fixed it. If the lead in is too large mc will skip it.

[MATT Q]

I've also seen when you copy a toolpath operation it messes it up and it will do some stragne stuff that is when I just rewrite the path instead of copying and it seems to work may not in this case. good luck:)

[Rekd™]

From QC..

 

quote:

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I can duplicate what you are describing so I logged the problem as a Mill bug #24781

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'Rekd

[kathy]

Another pocketing problem: (sorry rekd - I'm hi-jacking your thread).

 

I am machining a part with a .058 deep pocket into .090 thk material. I do not want the cutter to feed back over previously pocketed areas, because the material lifts up into the cutter. How can I force Mastercam to recognize previously machined areas? It is acceptable to lift up the tool and rapid over to start pocketing again.

 

Kathy

[Zero]

quote:

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How can I force Mastercam to recognize previously machined areas?

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I don't think that is possible with MC...I could be wrong though. Off the top of my head I can think of 2 solutions. One is, depending on the pocket shape you might be able to accomplish this by your pocketing style, on an odd shaped pocket I would think that constant overlapping spiral or zig-zig would be your best bet this way, but this isn't a sure fire solution.

 

The other, which would take alot more work is to draw out exactly the path you want the center of your tool to take and write a contour program with this geometry with tool comp off. I would do this by writing a pocket program that came close to what I wanted, backplot it and save the geometry , then clean that geometry up to what I needed it to be and go from there. It's a pain in the arse, I know, but I can't think of any other way to do it at the moment.

[Rekd™]

Have you tried ZigZag or OneWay?

 

I regularly do pocketing on thin, (.02") alum with close tolerance floors. I use a vacuum. I can mill around the outline, and leave a .001-.0015" thick floor without breaking thru, then tear the parts off afterwards. Very cool stuff.

 

'Rekd