Lest we Forget scene problem with Gcode

[scoobieguy]

Hello, I've been trying to figure this out before remembrance day,
I want to give this to our local school for the Nov 11th ceremony and another to my local legion.

However, I'm having major problems with my gcode, see the attached images. any suggestions,
I created a DXF from a free DXF, I cleaned up as many points as I could in Inkscape

then exported the file as new DXF, then crate a new part in Sheetcam which look to scale,
I run the post processor

then open the file with Openbuild and it looks completely wrong and goes off the set sizes.

Thanks in advance

[scoobieguy]

Looks like I should have posted in the help forum, if admins can delete this post
I can seem to delete it myself
Thanks.

[BrayD]

I've notice differences between saving as DXF and exporting as SVG from Inkscape. You can bring either file type into Sheetcam. Haven't figured out why, but SVG's get shifted in my Sheetcam produced G code. DXF works better for me. Perhaps SVG will work better for you.

[scoobieguy]

It looks like it might just be a 3d view problem in openbuilds, if I rotate the part is seems to stay within the boundaries

LWF_problem4.jpg (11.73 KiB) Viewed 4814 times

LWF_problem4.jpg (11.73 KiB) Viewed 4814 times

I tried a file from another user the jackolantern and the same thing happens where it looks out of boundaries, but because of the pierce points it looks skewed
I'm pit a marker instead of the plasma cutter holder and see the result

[BrayD]

A marker is a great idea. This is the issue I was running into. When I used an SVG to make the G code, it was shifting things slightly - to the point that I would have zero thickness in some areas.

.

.
When using a DXF to make the G code, everything fell into place. Still can't explain it, but it worked.
.

dxf .png (593.37 KiB) Viewed 4805 times

dxf .png (593.37 KiB) Viewed 4805 times

[acourtjester]

Looks like the outside line is shifting do you have that set on a different layer?? What software are you using to make the G-code??

[BrayD]

Agreed. It's all on the same layer, the only difference is one was generated from importing an SVG and the other from importing a DXF (into Sheetcam).

I don't want to hijack this thread, just wanted to show an example of a potential solution for scoobieguy.

[adbuch]

I opened your dxf file, linked/joined to eliminate crossovers/unwanted intersections, imported the edited dxf to SheetCam - and it appears that it would cut fine.

David

Lest-we-forget-ReducedPathsv31 linked.dxf

(901.99 KiB) Downloaded 21 times

Lest-we-forget-ReducedPathsv31 linked.dxf

(901.99 KiB) Downloaded 21 times

[adbuch]

At your current size of about 11" x 22" - many of the details are thinner than 1/32" and will most likely blow out when cut. I would recommend either scaling it up to maybe at least double the size, or doing some editing to modify these problematic areas of the file. Also - I would most definitely use FineCut consumables on this one - assuming your material thickness is 10 ga. or thinner.

David

[adbuch]

I have no experience with Openbuild so I can't help you there. Using a Sharpie holder attached to your torch is a good idea so that you can draw your file (instead of cut) to see what it looks like. I have personally experienced no significant difference between dxf and svg as far as importing to SheetCam. Both seem to provide a good result - although sometimes the g-code from the dxf is more compact that from the same file imported in svg format.

Here is a demo video of my sharpie pen holder drawing a file instead of cutting.
https://www.youtube.com/watch?v=4WYMMRuzWbU

David

[scoobieguy]

Thanks you all,
adbush for fixing the dxf and tips about sizing and consumables, I like your marker holder, I will make one to adapt to the torch holder.
and brayd for tips on importing svg vs dxf

I now suspect my sheetcam post processor is changing the way the file is processed, i'm running a custom JD's Garage table and the post processor for sheetcam they supplied which implements g53

g53.jpg (17.96 KiB) Viewed 4770 times

g53.jpg (17.96 KiB) Viewed 4770 times

i'm looking into the one from blouchip https://forum.sheetcam.com/t/grbl-plasm ... otary/7342
Which doesn't seem to leverage g53.
So many things to learn.

[adbuch]

[BrayD]

I played with the SVG vs DXF thing again this weekend and successfully cut a (fairly large/complex) part using SVG. That makes me happy as I prefer to use Inkscape's exporter rather than the 'save-as' feature to get my file. Strictly user preference.

Sounds like you're on the right path to get your issue sorted, just wanted to hop in here and clarify for anyone reading this in the future. SVG vs DXF is a variable to play with, but I'm not getting consistent inaccuracies using one over the other.

[adbuch]

Here is a simple file from Inkscape both saved and svg and exported as svg. The g-code is identical.
David

[BrayD]

Awesome. That confirms I had another issue somewhere.

[adbuch]

Awesome. That confirms I had another issue somewhere.