I designed a very simple part (wrapped job) in Aspire. It's a cylinder with three different diameters. I run the job and the two larger diameters end up larger than the design spec.
The material is Delrin and it's the first time I'm working with it.
The tool is a 0.25" end mill (standard, not ballnose).
I've checked the machine and it doesn't seem to have a problem. Tell it to move an inch and it moves an inch.
I'm Using 3 pockets in Aspire to create the toolpaths. The first and last diameters (pockets) cut larger than design (not pocketing as deep as they should). The second pocket cuts right on. If I were losing steps, the second pocket would have an error as well. It doesn't.
In the past I've gotten strange results by trying to 3D carve in rotary with a standard end mill. But I'm using a pocketing strategy and the standard end mill shouldn't present any problem. The gcode looks fine to me.
Aspire seems to be working fine. My machine seems to be working fine. I'm using Mach3 and have not made any changes to the configuration since my last job (which ran as expected, but it was a vcarving, not pocketing). Everything seems to be working, but the results are not right and I'm at a complete loss to explain or fix it. Any suggestions or ideas from anybody would be greatly welcome.
I've attached the Aspire File, the toolpath and an image that may better explain my results.
Ed
Not getting the results I expect.
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- Vectric Wizard
- Posts: 338
- Joined: Wed Aug 12, 2009 2:09 am
- Model of CNC Machine: Taig Mill and Self Built Routers
- Location: Space Coast, Florida
Not getting the results I expect.
- Attachments
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- Test Plug.crv3d
- Aspire File
- (71 KiB) Downloaded 246 times
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- Test Plug.txt
- G-Code (all three toolpaths combined)
- (16 KiB) Downloaded 220 times
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- Vectric Wizard
- Posts: 338
- Joined: Wed Aug 12, 2009 2:09 am
- Model of CNC Machine: Taig Mill and Self Built Routers
- Location: Space Coast, Florida
Re: Not getting the results I expect.
Just for grins, I created 3D components from the pocket vectors and ran the job as a 3D carving (using a 0.125" ballnose). Came out exactly right. Each dimension exactly the size designed. Of course it took a lot longer to run and I have to clean up the radiused corners, but overall it might be faster than having to manually turn the oversized parts back to spec.
I noticed I had used a smaller depth of cut on the larger radius parts, so I set everything to the same settings as the smallest radius (which had cut correctly). No difference in results. Still oversized on the larger radius.
The length of the larger radius parts was 0.25". I wondered if using a 0.25" tool to cut a 0.25" pocket would somehow have made a difference. Switched to a 0.24" end mill and reran the job. No difference.
So, I'm still sitting here scratching my head trying to figure out why things aren't working.
At this point I'm pretty sure it's not Aspire or my hardware that is doing it. Since there haven't been any responses here I'm taking that as further confirmation that it's not related to Aspire.
That leaves Mach3 and i'll pursue that in other forums. Thanks to all who took a look.
Ed
I noticed I had used a smaller depth of cut on the larger radius parts, so I set everything to the same settings as the smallest radius (which had cut correctly). No difference in results. Still oversized on the larger radius.
The length of the larger radius parts was 0.25". I wondered if using a 0.25" tool to cut a 0.25" pocket would somehow have made a difference. Switched to a 0.24" end mill and reran the job. No difference.
So, I'm still sitting here scratching my head trying to figure out why things aren't working.
At this point I'm pretty sure it's not Aspire or my hardware that is doing it. Since there haven't been any responses here I'm taking that as further confirmation that it's not related to Aspire.
That leaves Mach3 and i'll pursue that in other forums. Thanks to all who took a look.
Ed
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- Vectric Wizard
- Posts: 338
- Joined: Wed Aug 12, 2009 2:09 am
- Model of CNC Machine: Taig Mill and Self Built Routers
- Location: Space Coast, Florida
Re: Not getting the results I expect.
Finally figured out what the issue was. The pulse stream from Mach3 was inverted. I don't know when or how, but the pulse output on my system was changed to an active hi configuration instead of active lo. The machine ran smoothly with the inverted pulses and 3D rotary carving was spot on, but pocketing depth was off. Go figure. Now with the pulse configuration set back to the correct values everything seems to be working as expected.
Just wanted to document the solution in case somebody else has a similar issue some day.....probably unlikely though.
Ed
Just wanted to document the solution in case somebody else has a similar issue some day.....probably unlikely though.
Ed
- Rcnewcomb
- Vectric Archimage
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Re: Not getting the results I expect.
Thanks for the update. The more we know, the better we become at our craft.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop
10 fingers in, 10 fingers out, another good day in the shop