Inkscape templates

I’m wondering if inkscape can be tweaked a bit to make it more accurate for CNC designs.
And if those tweaks can somehow be put in a template.

Things like the default in mm or inch
the output ppi can that perhaps be set in the template?

When changing the stroke width it affects the overal inline / outline is there a way to change that in a way that is more ideal for CNC use?

It’s probably better to use a real CAD program when size accuracy is important, but since inkscape is more easy to start with I wonder if we can make it even more usefull by providing a few templates that get the annoyances a bit out of the way.

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You can edit the default template to have whatever settings you like.

This youtube video explains how to open the default template, change it and save it.

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I’ve made a first attempt.

The first thing i try to figure out is how to force the ppi resolution so that whenever the template is loaded the ppi resolution gets the correct default,

Inkscape has seems to be able to do this (there is a 300ppi CD cover template) however i can’t figure out how to fix it in the template. The bitmap ppi setting is in the Inkscape Preferences menu and that seems not to be stored in the Document Properties… :frowning:

I just discovered that when I load the 300ppi CD cover, that inkscape does NOT change the ppi resolution at all… …sigh

I’m now playing the tutorial, I hope I learn a bit more about this.
------------ template below this line ------------
244x122 Sheet metric mm

I attached the first template (the blank space on this post) Hmm this kinda sucks a bit a blank template gives a white space.

Anyway this is my first attempt : 244x122 Sheet metric mm

As a little reminder i’ll add this info on dpi ppi defaults
dpi = dots per inch, ppi = pixels per inch

Apple systems 72dpi
Windows systems 96dpi
Inkscape 90dpi

Apple retina appears to have yet another default (somewhere between 200 and 220 ppi)
Adobe illustrator ?
PDF uses 72 ? is this true? or is that mac-only?
Apache batik 96dpi
Corel
Freehand
FireFox 96dpi (is this also true on a mac?)

I use inkscape on a GNU/Linux machine, I wonder if inkscape on windows or apple has different defaults.
Just to get a little closer to the bottom of this madness.

To me it doesn’t make any sense at all to have an inch related system controlling / messing with scalable vector graphics.
I mean all works fine in the display domain, but once you need to output to the real world then all can turn into a pile of crap when ‘imperialism’ kicks in…

To me a millimeter is a millimeter and an inch an inch, why are there pixels and dots messing with real world measurements??? I can’t make cheese form this…

In a way I prefer to work in FreeCAD, though for people starting with CNC it would be far more intuitive to start in inkscape,

What is the future of this? Will this madness continue when display resolutions increase?

How is this dealt with on an industrial level?
Imperial of Metric…

What would be the best way to go?

EDIT


So inkscape even has 2 dpi defaults???
Absolute units and user units… WTF? Smells like a workaround around a workaround and that we need to work around those workarounds to get something that’s somewhat accurate as long as you don’t send it to another machine.

EDIT 2

I just learned that ‘apple world’ uses 72 dpi, the ‘windows world’ uses 96 dpi and that the ‘SVG world’ uses 90 dpi However there is nothing about this to be found in the w3c SVG specification.

Then there is the CSS spec. where there is a statement that say’s the default is (72/0.75) and that is the magical 96 dpi…
Not sure how all of this is tied together with xml and what to see as the real standard…

EDIT 3
FreeCAD has 2 options to export SVG Translated (for display) and RAW (for CAD)
At this point I don’t know the difference, I first need to figure out how to export anything…

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In my experience most of the industrial world operates on .dxf files, but those have their own challenges with some programs not opening .dxf files generated from other programs. This last week I ran into an issue where the laser cutting shop couldn’t open the .dxf files I was saving so we had to switch to .dwg files.

It’s been my experience that most people end up with a system which works and then it isn’t messed with again. Sometimes that even means a computer which is just set to never update. Hopefully as digital fabrication becomes more affordable and ubiquitous it will get better :man_shrugging:

What can we do as a community to make things better? I’m going to put together an OnShape → Maslow video for the update this week because I it took me a long time to get that process worked out.

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I didn’t expect to find this can of worms. :slight_smile:

in a way i wish the FreeCAD ‘path workench’ was a bit closer to workable but the learning curve is a bit bigger then i can handle at this moment, dawing with the sketcher works like a dream, but at this point i cant figure out how to export to svg. it’s stuff like this i need to get figured out before i can start to build a machine, working on free software only has a few extra challenges.

so it looks like inkscape at this point is the only feasible option for me.

FreeCAD’s sketch tool is the best tool i came across, i hope this will soon be usable

on template topic:
there is an option to add a script to the template does anyone know if this can be used to set the dpi value?

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I’m sure you are aware of it, but I wanted to add to the discussion this little drop down

image

which let’s you switch the units from px to mm or inches seems relivant.

It doesn’t solve the issue of the .dpi of the saved file being platform dependant tho

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Yes that setting can be set as default in the template.

The template Uploaded has this setting.

The dpi setting should really be in the template as this is the very thing that can break things.

In Document Propperties, firrst tab, upper right corner, there you can set this to whatever you want as default in the template.

And right now i’m again confused why i’m messing with pixels in a vector drawing tool in the first place.
Once i draw a line and I define that line is 1cm or 1inch, then THAT should determine the output. But when i change the dpi then 1cm nolonger is 1cm??? What is it that I don’t get? :slight_smile:

I’m very tired today so maybe I better leave it for now.

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The missing piece is that you’re dealing primarily with graphics software, not CAD software.

In the CAD world, resolution (something per some distance) isn’t a relevant topic. 1 is just 1. Not 1 inch, not 1mm, etc… It’s important to know what the unit is (so you don’t mix them up) and you need to know it in order to re-dimension something but for pure drawing tasks, it’s irrelevant to the software because the machine handles it for you. You really don’t want to have to deal with encoder steps per inch (you really can’t anyway) nor should your design need to change based on the intended finish; again, the machine/tool/feed/speed all determine that instead.

Graphics software, on the other hand, is intended to output something. Usually on paper or a screen so it’s necessary to know the resolution of that output device in order to correctly size something when it’s output. Yes, it’s vector art and ostensibly the resolution is determined by the output device so you don’t necessarily need to know it but Inkscape also allows raster images to be imported and some of its effects are actually output as a raster layer rather than vector. For raster images to be output with appropriate quality, it’s crucial to know the output resolution of the device and therefore the native resolution of the document is important.

You also sometimes have control over the resolution of the output device: consider the high speed inkjet equipment used for billboard printing. If you’re designing a billboard that’s going to be hung 100’ off the highway and your audience will see it for 0.5 seconds while flying by it at 70mph, a 300dpi image is overkill in a way that’s detrimental to the process. (just 1" of that 15’ strip is over 16 million pixels.) So billboards are printed at something like 50 dpi. But that same inkjet device can print point-of-purchase displays that will be viewed from just a few feet away or closer… photographic quality is desired so that might be output at 1200 dpi. It’s necessary to know this and set your document up appropriately.

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PDF is resolution independent and has no native resolution. The graphics software used to output the PDF will determine the resolution of the document.

Is that a 1-step workflow? I’d really like to be able to CAD/CAM in one step and I’m finding F360 to be cumbersome in that regard.

it’s still the same steps, first you create the model, then you create the g-code, then you run the g-code.

there’s a (long) video that shows the CAM and milling steps (on a different machine) steps in onshape that I mention in this topic Good video showing the CAM workflow in onshape

Sorry, I said “1-step” I meant 1-app. (Other than Ground Control, I mean).

@dlang is right that it can be a one app process using a plugin for onshape called KiriMoto. KiriMoto is really designed to do 3D contours not cut around the edges so it might take a little hacking to get it to work well. The biggest issue I could see would be that there isn’t a clear way to layout many parts on a sheet of plywood (that I saw). I haven’t played around with it too much because their website was down the day I set aside time to look at it. I’d like to give it another go.

My workflow is to export a .dxf file from OnShape, convert it to a .svg file in Inkscape, then generate gcode from MakerCAM. It’s a lot of steps, but it works reliably.

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@dlang is right that it can be a one app process using a plugin for onshape
called KiriMoto. KiriMoto is really designed to do 3D contours not cut around
the edges so it might take a little hacking to get it to work well. The
biggest issue I could see would be that there isn’t a clear way to layout many
parts on a sheet of plywood (that I saw). I haven’t played around with it too
much because their website was down the day I set aside time to look at it.
I’d like to give it another go.

you just import many parts into the kiri:moto windows and move them around.

if your parts are the same thickness as your stock, it will just cut the pockets
and around the parts. it does tabs, etc

My workflow is to export a .dxf file from OnShape, convert it to a .svg file
in Inkscape, then generate gcode from MakerCAM. It’s a lot of steps, but it
works reliably.

watch the video and try the kiri:moto approach

David Lang

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Thanks for the tip, I will give that a go. It looked fantastic from what I remember

Thanks for that! @TheRiflesSpiral

That sounds like: This will always stay an issue. So every time Apple steps up the retina resolution then the whole issue pops up again.
Maybe someone should fork Inkscape and name it CADscape? :slight_smile:
It would be nice if Inkscape had just somekind of CAD friendly mode.

I hope I can figure out how to still make this Template as I had in mind.
But after reading your explanation it’s more clear to me now that I should shift my focus to FreeCAD.

Yes, as long as one piece of software is used to design for multiple output formats, it will always need to be dealt with. It’s just the nature of the Graphics world. Ever since we moved away from lead type we’ve had to consider resolution.

I would be thrilled with a CADScape fork! There are plenty of free CAD options, though. If you’re looking for 2D, check out Dassault’s DraftSight. For 3D on Linux, you might look into my.sketchup.com. It’s Sketchup in an HTML 5 browser.

In borwser CAD doesn’t work for me at all, i’m currently on a data capped cellphone connection, it’s already a struggle to load the Maslow forum… So that rules out browser CAD for me. Maybe when i’m at home, but most of the time when I have tome to do drawing i’m not at home. So that leaves FreeCAD as one of the few feasible options for me. And the last time I tried to use Sketchup it didn’t work at all on Linux+FireFox
But maybe that also was a connectivity issue, not sure…

I’m looking if there is a way to export the FreeCAD sketcher drawings to SVG. Until the path workbench is stable… Just need some easy way to get from FreeCAD to GroundControl. But since i have not been able to figure thatone out yet i’m still messing with inkscape since that at this point seems to be the more easy route.

I think someone did that! It’s QCAD (QCAD - QCAD: 2D CAD) I’m not sure I read that specifically but enough of the menus are the same that I think there’s some inkscape DNA in there. QCAD will generate gcode too :wink:

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