undersized 2d pocket

[gusspec]

reposted from wrong forum....

I am pretty sure I am missing something obvious, but I am having trouble with this operation. I have set it for no material left over and yet it does not mill parts of the pockets/islands. I tried doing just one section[the actual pocket] and it appears to do the same. I appears to be leaving about .025

Just tried adaptive clearing on the same surfaces and it appears to generate toolpaths that do the same.

[edit]

notice how it ignores the radius around the hole, this is not a seperate surface, and is highlighted when selecting features to mill as one with that surface

[Steinwerks]

The hole (or pocket rather) is a selection issue. Selecting surfaces for 2D geometry is not terribly reliable. Try selecting edges instead.

As far as inaccurate sizing, this could be a settings issue somewhere in your toolpath parameters, but it's hard to say without seeing them. Check your Stock to Leave under Passes, as that would be my first guess. Second is make sure that Finish Pass is checked, and that you aren't trying to take too much material for the tool being used. Recently someone had undersize pockets due to just tool deflection exacerbated by using a conventional cut.

Lastly, Adaptive Clearing toolpaths are roughing strategies only, and should not be counted on to create finished geometry, and so one should definitely be using the Stock to Leave parameter before using something like 2D Contour or Horizontal to finish prismatic parts.

[Steinwerks]

Oh, and if you could either take screenshots of the various tabs for your toolpath or export and share a .F3D file here that would be helpful.

[gusspec]

it isn't tool deflection, .025 per side with a carbide 1/8 EM at 10k rpm in delrin in a big VMC is not happening.

I tried finishing passes, doesn't seem to do anything

It is really acting like the tool is bigger than it is.

nothing explains it ignoring that bump out around the hole

I find finish passes a waste of machine time for non critical contours. I mean if it was a couple thou off that is one thing.

for some reason I cannot get a screenshot of the drop downs, they disappear when you try to capture

horizontal is not generating a toolpath and not erroring for some reason, will grind through that

[HughesTooling]

We've had a few of these complains and so far it's always down to the regidity of the machine, see this thread for example. What material are you machining on what machine what size cutters.

Mark

Edit OK started typing before your last post. Sounds like it should work on your setup. Can you upload the file.

[Steinwerks]

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@gusspec wrote:

it isn't tool deflection, .025 per side with a carbide 1/8 EM at 10k rpm in delrin in a big VMC is not happening.

I tried finishing passes, doesn't seem to do anything

It is really acting like the tool is bigger than it is.

nothing explains it ignoring that bump out around the hole

I find finish passes a waste of machine time for non critical contours. I mean if it was a couple thou off that is one thing.

for some reason I cannot get a screenshot of the drop downs, they disappear when you try to capture

horizontal is not generating a toolpath and not erroring for some reason, will grind through that

---

Big VMC is relative 

Anyway, if you could possibly export the file as a .F3D and attach it here, I'm betting this is a selection and parameter issue.

Not a screenshot of the dropdowns, but the parameter tabs when you edit the toolpath.

Example:

[gusspec]

well, I cannot get the parameter tabs to not disappear when trying to capture an image.

tried internal cnc compnesation, and it was different but still wrong

there is no line or surface break at the detail that it is ignoring. the surface show up as continuous. Same if I try to contour afterwards, but it wants to go outsid ethe contour

a pocket shoud be the size and shape of the pocket unless you tell it otherwise

I'm a profit making entity, I don't post my drawings on the internet, not my decision.

[gusspec]

passes

tolerance .0005

comp left

type in computer

finishing passesX

1

stepover 0.0125

finish feedrate 40

repeat[no]

overlap 0

preserve[no]

bothwaysX

max stepover .04

raduis 0

use morphed yes

allow stepover cusps yes

smoothing .004

rest unchecked

[Steinwerks]

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@gusspec wrote:

well, I cannot get the parameter tabs to not disappear when trying to capture an image.

tried internal cnc compnesation, and it was different but still wrong

there is no line or surface break at the detail that it is ignoring. the surface show up as continuous. Same if I try to contour afterwards, but it wants to go outsid ethe contour

a pocket shoud be the size and shape of the pocket unless you tell it otherwise

I'm a profit making entity, I don't post my drawings on the internet, not my decision.

---

1) How are you taking screenshots? If you are in Windows you have a couple options. 

a) Use the Snipping Tool (if you search for Snipping in the Start menu it'll show up) which lets you select an area of the screen.

b) Hit Alt+Prt Scrn and open Paint or any image editor and Paste in to an image.

2) Without seeing your geometry selections it's hard to know how you selected them. And it matters.

3) Yes, it should, but there's more to it than that in any CAM system that I've used (GibbsCAM, Mastercam, CAMWorks, HSMWorks/Xpress, and Fusion 360).

4) That's fair. Can you model up a dummy part with the same parameters? Also, which post processor are you using?

[gusspec]

its not the post, note the straight line across radiused area

there is not straight line there and no gap in the contour

heidenhain generic

[HughesTooling]

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@gusspec wrote:

I'm a profit making entity, I don't post my drawings on the internet, not my decision.

---

Can you send it direct to Autodesk support for help\advise [email protected] It's all just guesswork without a file.

Mark.

[gusspec]

runnign a countour on the pocket and the island fixed that for reasons that are not clear, but there is still a half moon of material in one spot. cannot at present get a contour to work as it wants to be on the outside of the line rather than a proper pocket finishing routine

[Laurens-3DTechDraw]

---

gusspec wrote:

well, I cannot get the parameter tabs to not disappear when trying to capture an image.

tried internal cnc compnesation, and it was different but still wrong

there is no line or surface break at the detail that it is ignoring. the surface show up as continuous. Same if I try to contour afterwards, but it wants to go outsid ethe contour

a pocket shoud be the size and shape of the pocket unless you tell it otherwise

I'm a profit making entity, I don't post my drawings on the internet, not my decision.

---

I love the fact that everybody is trying to help you out with a new piece of software that you probably still need to get a little feeling for, and therefor might assume things that are not actually true, and it's the software's fault and the people that are trying to help are at fault without saying anything.

So if you can't or won't post the part online, you can alsways make a dummy part. A part with the same problem but not your actual parts.

Or share it with the Autodesk CAM support team like suggested by @HughesTooling

[gusspec]

I don't know who's posts you are reading but I started out with"I am pretty sure I am missing something obvious" meaning just that.

As I see it I have gotten several specific suggestions.

machine rigidity, post processor, feature pickup

rigidity: low hour CAT40 VMC, makes parts all day, not the issue. Not a flashcut

post processor: path is incorrect in the software, so it is not the post.

feature pickup: seems to me it is related to this, but when selecting the features to mill, the feature to the right of the image I posted highlights in its entirety. If I try to mill it by itself rather in combination with the rest of the features, same thing. If I select the edge as a toolpath that semi circle highlights as part of the path, there is no line/edge/feature which cuts straight across the surface as the toolpath does.

I apologize if my language is not a flowery and my praise is not as effusive as you would like, but typing is not my primary skill and it takes me forever to create a post, so I tend towards curtness. I am also trying to get a job off of a machine which makes me irritable when my sofware will not obey my inarticulate commands.

attached is a closeup of the toolpath in question

[Steinwerks]

The point is that we can't help you without better details. Since you can't share the part here (which as I said is understandable), I highly recommend sending it to [email protected] who will share it with no one. Their job is helping their customers, after all.

You could also try inviting someone to the project who can then be removed once the issue has been resolved, although no one seems to do that anymore.

[HughesTooling]

So have you sent it in the Autodesk support because without the file no one's going to be able to help. You might have found a bug but it will not get fixed without the file or you might have something selected wrong again without the file who knows?

Mark

[gusspec]

believe it or not in 30 years of using computers I have never had reason to create a screenshot............

[HughesTooling]

There was another user on here a while back who would not upload any file who wasted about a month of his time. Eventually someone managed to get him to understand how model selection and boundary selection worked and all his problems went away. If he'd uploaded some files he could have saved hours of his time. So just send the files to support before you wast more of your time.

Mark