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Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Mon Feb 15, 2016 9:01 pm
by zerb
Little issue i ran into tonight when trying to slice and print some calibration pieces on my Lulzbot Mini.

this plug here, seems fine until the very last layer, i took screenshots to show the issue. its making a D shaped hole on layer 50 out of 50, layer 49 its still printing in a full circle.

Image

49th layer
Image

50th layer (Top layer)
Image

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Mon Feb 15, 2016 9:58 pm
by pcman
Please post the factory file. That will make it much easier for someone to identify the problem.

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 12:53 am
by atunguyd
I have had similar things happen, sometimes with a layer in the middle doing this. All times this was solved by tweaking the first layer settings (normally 150% and changed to 149%)

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 4:10 am
by dkightley
There's obviously a minor inconsistency in the mesh that S3D is picking up on and is interpreting incorrectly.

Try running the shape through the online repair service: https://netfabb.azurewebsites.net/ Alternatively, try adding 0.0001 to your layer thickness and try slicing again.

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 6:51 pm
by zerb
pcman wrote:Please post the factory file. That will make it much easier for someone to identify the problem.

here is the factory file, the only thing i did to it was change the first layer height from 150% to 149% as suggested below and the program sliced it properly.
test_plug.factory
(23.88 KiB) Downloaded 412 times

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 7:36 pm
by jimc
yes this pretty much confirms what doug said. there was probably a very minor mesh issue that s3d was picking up on. changing the layer height a bit allows it to land at a different spot.

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 8:27 pm
by pcman
jimc wrote:there was probably a very minor mesh issue that s3d was picking up on.
Agreed, and that's not uncommon. But in this case, it glitches even though the model passes all S3D's checks, which I haven't seen happen before.

I wasn't able to re-create the error to the same magnitude as shown in the image by setting the first layer height back to 150%.

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Tue Feb 16, 2016 9:32 pm
by zerb
its happening to another part now. tried changing the first layer height to no avail, bottom solid layers as well, cant get it to slice properly.

Image
Image
perimeter-wt.factory
(4.03 KiB) Downloaded 416 times

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Wed Feb 17, 2016 12:05 am
by jimc
yes its your model. your model is a bunch of unconnected surfaces. nothing is joined into a complete solid. prior to slicing your model, if you take the cross section tool and select z axis. move the slider down so you can see inside your model. you can clearly see all the individual surfaces you have.

Re: Making Circular Hole D Shaped On Top Layer After Slicing

Posted: Wed Feb 17, 2016 7:02 pm
by zerb
jimc wrote:yes its your model. your model is a bunch of unconnected surfaces. nothing is joined into a complete solid. prior to slicing your model, if you take the cross section tool and select z axis. move the slider down so you can see inside your model. you can clearly see all the individual surfaces you have.
interesting, didnt know what that tool did to be honest with you. downloaded this thing right off of thingiverse for calibration use too!