Laserengraver not properly scaling in mm (gcodetools)

[Nico Koch]

When creating eg. a rectangle in mm and then Laserengrave, the resulting product is divided by 3.54331. This is the exact difference between px and mm. A rectangle of 85 mm x 35 mm ends up being 24.135 mm x 9,975 mm.

[Alvin Penner (apenner)]

thank you for taking the time to submit a rteport! could you attach some additional info?
- which OS?
- which version of Inkscape (see the menu item Help->About)
- which file format are you using to produce the files for laserengrave?
- could you attach a sample svg file for testing purposes, as well as the file you sent to laserengrave?

[phiscribe (dcbevins)]

If you are talking about dxf then this bug report might be relevant: https://bugs.launchpad.net/inkscape/+bug/1643383

Quick thing to try, on the dxf save dialog, set the base unit to PX.

[lgj (lgj)]

I see same problem when using "J tech Photonics Laser tool" to generate Gcodes

[Alvin Penner (apenner)]

@lgi:
thank you for taking the time to submit a report! could you attach some additional info?
 - which OS?
 - which version of Inkscape (see the menu item Help->About)
 - which file format/extension are you using to produce the files for J Tech?
 - could you attach a sample svg file for testing purposes, as well as the file you sent to J Tech?

The reason I am asking for specific details is because there have been recent changes made in the scaling of some of these output formats, so we need to know precisely which version/format was used.

[Nico Koch (nicporkoch)]

My apology for too little info. Inkspace 0.92.1, Win 7, created rectangle
in inkspace, grbl Laserengraver. Just confirmed, J Tech Photonics Laser
Tool same problem.
On May 1, 2017 20:40, "Alvin Penner" <email address hidden> wrote:

> @lgi:
> thank you for taking the time to submit a report! could you attach some
> additional info?
> - which OS?
> - which version of Inkscape (see the menu item Help->About)
> - which file format/extension are you using to produce the files for J
> Tech?
> - could you attach a sample svg file for testing purposes, as well as the
> file you sent to J Tech?
>
> The reason I am asking for specific details is because there have been
> recent changes made in the scaling of some of these output formats, so
> we need to know precisely which version/format was used.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1687306
>
> Title:
> Laserengraver not properly scaling in mm
>
> Status in Inkscape:
> New
>
> Bug description:
> When creating eg. a rectangle in mm and then Laserengrave, the
> resulting product is divided by 3.54331. This is the exact difference
> between px and mm. A rectangle of 85 mm x 35 mm ends up being 24.135
> mm x 9,975 mm.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/inkscape/+bug/1687306/+subscriptions
>

[Alvin Penner (apenner)]

since the output format has not been specified or indicated, I am going to assume that you are probably using dxf output.

If you are using dxf output, then I would recommend upgrading to the most recent version. The output dxf scaling was changed in rev 15590 in response to Bug 1672066
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15590
and rev 15469 in response to Bug 1660967
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15469
to deal with scaling problems.

You can get the latest version of this output by downloading it from
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/files/head:/share/extensions/

You will need to download the files: dxf_outlines.py, dxf_outlines.inx, and inkex.py
and place them in the directory:
\Program Files xxx\Inkscape\share\extensions\

To be on the safe side, make a backup copy of these three files before you replace them with the new versions. If the new version continues to give problems, then attach the appropriate svg files and dxf files here so that we can diagnose the problem. Note that the new versions assume that the default resolution in Inkscape is 96 dpi, which is different than the previous 90 dpi.

[Nico Koch (nicporkoch)]

The output is in gcode nc files for grbl engraving
On May 1, 2017 22:15, "Alvin Penner" <email address hidden> wrote:

> since the output format has not been specified or indicated, I am going
> to assume that you are probably using dxf output.
>
> If you are using dxf output, then I would recommend upgrading to the most
> recent version. The output dxf scaling was changed in rev 15590 in response
> to Bug 1672066
> http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15590
> and rev 15469 in response to Bug 1660967
> http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/15469
> to deal with scaling problems.
>
> You can get the latest version of this output by downloading it from
> http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/
> files/head:/share/extensions/
>
> You will need to download the files: dxf_outlines.py, dxf_outlines.inx,
> and inkex.py
> and place them in the directory:
> \Program Files xxx\Inkscape\share\extensions\
>
> To be on the safe side, make a backup copy of these three files before
> you replace them with the new versions. If the new version continues to
> give problems, then attach the appropriate svg files and dxf files here
> so that we can diagnose the problem. Note that the new versions assume
> that the default resolution in Inkscape is 96 dpi, which is different
> than the previous 90 dpi.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1687306
>
> Title:
> Laserengraver not properly scaling in mm
>
> Status in Inkscape:
> New
>
> Bug description:
> When creating eg. a rectangle in mm and then Laserengrave, the
> resulting product is divided by 3.54331. This is the exact difference
> between px and mm. A rectangle of 85 mm x 35 mm ends up being 24.135
> mm x 9,975 mm.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/inkscape/+bug/1687306/+subscriptions
>

[Alvin Penner (apenner)]

could you provide a sample svg file and a sample nc file, so that we can confirm the behavior?

[Nico Koch (nicporkoch)]

I did both V0.48.5 and V0.92.1 as examples

On Tue, May 2, 2017 at 12:51 PM, Alvin Penner <email address hidden> wrote:

> could you provide a sample svg file and a sample nc file, so that we can
> confirm the behavior?
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1687306
>
> Title:
> Laserengraver not properly scaling in mm
>
> Status in Inkscape:
> New
>
> Bug description:
> When creating eg. a rectangle in mm and then Laserengrave, the
> resulting product is divided by 3.54331. This is the exact difference
> between px and mm. A rectangle of 85 mm x 35 mm ends up being 24.135
> mm x 9,975 mm.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/inkscape/+bug/1687306/+subscriptions
>

[Alvin Penner (apenner)]

thank you for the files.
marking as confirmed based on the above attached files. (I am not sufficiently familiar with gcodetools to be able to reproduce the test output)

[lgj (lgj)]

I am using Inkspace 0.92.1, Win 10 and J Tech plugin v1.7. I think Nico's examples represent my problem

[Alvin Penner (apenner)]

you could also try sending an email directly to the original developers:
http://www.cnc-club.ru/gcodetools

however, this site does not seem to be very active...

[Alvin Penner (apenner)]

likely a duplicate of Bug #1685740

[Gray Cat (graycat)]

Hello!

Sorry for necropost, but I've bumped into the same problem.

The solution is: check the "File" / "Document Properties" / "Scale" setting: after you change "Display units", the "Scale" tends to adjust to another value by itself.

Set the "Scale" to == 1, then the output is 1:1.