Inkscape Laser gcode scaling

I’m exporting dxf files from pepakura and opening them in inkscape 92.2. When I run J-Tech Laser extension, the resulting gcode file items are scaled about 100 times to large. I’ve set everything to mm that can be set and items still come out huge. If I just run the gcode to path extension everything scales correctly. But the I don’t get the laser on and off commands (naturally). Any ideas?


Screen shot of your jtech settings? I use that plugin and it works great, must be something that was overlooked.


100x’s would suggest a Meters to mm scaling issue on import.

Here’s the setting screen shot and results in Repetier.

My MPCNC useable bed size is 950mm X 480mm.

I’ve done two clean installs of Inkscape, one on a Mac and one on a PC both machine produce the same results. So whatever I’m missing I’m consistent. :slight_smile:

It is you dxf import size.

In inkscape use the file-document properties to figure out what the dxf is.

I thought there was a dpi change in inskcape. I seem to remember a 93x from someone. In fact, I thought it was you, Ryan.

I’ve tried every document size I can think of in Inkscape Letter, A4, MPCNC bed size. Looks fine, displays fine, just outputs is scaled wrong. But I think your on to something with the dxf import size. If I just draw something in inkscape, the laser extension works fine. So I think things are going south with the import.

How about a link to the file you are having a problem with and one of us can try it. It is an import issue but I can’t remember off the top of my head how to fix it.

In Inkscape, have tried changing the parameters when you open (or import) the DXF file? When you open the file, you should see a window that looks like the attached screen. You can try to turn on or off the “scale to A4” and use different manual scaling factors.


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Ok, making progress. If I open the dxf file in Inkscape everything looks great and I get all three layers from Pepakura, but the gcode scaling is 100 times to big.

If I Import the dxf file into Inkscape, Inkscape flattens the the layers unto one layer, but the gcode scaling is correct.

I’ve attached a simple .dxf file from Pepakura you’ll have to change .txt to .dxf after download as .dxf is verboten for upload…

giftbox.txt (12.6 KB)

Inkscape’s native resolution changed from 90 dpi to 96 dpi, in the new stable 0.92.

I ran into the problem a couple of months ago… and I had to revert to Inkscape 0.91 to get the Jtech laser plugin to work properly again. I’ve got a couple of Ubuntu boxes and the plugin works fine with 0.91 and an ancient 0.43(?) but breaks with an “upgrade” to 0.92.


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I have no idea if it relates to this, but it may help. I had to work through some kinks when exporting .svg files as .dxf files in Inkscape. They would always come out way too big or way too small. I finally discovered what works for me. With inkscape open and file opened. Select all of your object and cut it so it removes it from the screen but is available for pasting. Go to File>Document properties. Set “Scale X” to one. If you did this while the object is still on the pallete it changes the object size. Re paste the object back on to the pallete. Choose entire object again click “resize page to drawing or selection.” Set both document units and display units to “PX” even if it will be mm in the program you import the file into. This takes care of the scaling issue with .svg to .dxf. Again i dont know if this applies to you but i think it may.




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I’ll give that a try when I get more CNC playtime… Thanks

The update of a drawing from .91 to .92 does not scale correctly for me in Estlcam so I downgraded to .91 new drawings worked fine just not updated.

Ok… Think I’m getting the process down. I’m trying to do this with just Pepakura and Inkscape. Every tutorial I find uses four to five programs to make this work. I have the steps down to burn 8.5 x 11 100 lbs paper sheets. But I’m upping the game to 22 x 28 poster board that I’ve preprinted with a plotter. First burn is under way.

[attachment file=43208]

That looks fancy, can’t wait to see the project.

Stuff like this minus a zillion hours with a Xacto Blade…

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