Category Archives: Inkscape

Cutting my first design from Inkscape to my craft cutter

I’ve spent about two weeks writing software for my custom craft cutting machine that replaces the manufacturer’s original program on the machine.  Why would I do that you ask?  Well, you can read the full story in another post, but for a short answer, because I could!  Well, the machine was given to me by my sister, and it was dead on arrival.  I received no cartridges or anything with it.  So I had to first, determine why it was dead, then my brain went directly to “ok, how does it work?”

Skipping over the next two weeks, I have it working and cutting with Inkscape perfectly.

However, there are some gotchas.

First and foremost, for cutting purposes, all our designs have to be simplified to a path.  So when you draw something on the canvas, you have to use the Object to Path menu to make this conversion.

Sometimes, it doesn’t seem to do anything visibly to the design, but if you skip this step, the output will not be desirable 🙂

Here I have drawn a simple star.  You can see the black outline and if you try to cut it as is, you will get some cuts but not the complete star.  Selecting the Path menu, then Object to Path, Inkscape will make the necessary changes internally and when you send this to the export extension, it will then cut perfectly.

ObjectToPath

Font’s are similar in nature:

InkscapeFont1

Here I have simply entered some text, set the font to Comic Sans, and made it big.  However, sending this to the HPGL export plugin would fail miserably because it is not a path, and Inkscape can only send Paths to HPGL.

We must always simplify our objects to a path.  However, with fonts it seems to be a little more challenging.  Simply clicking on Object to Path doesn’t do the trick. A font is actually an object made up of two parts, a fill, and a stroke.  Most of the time, the stroke is turned off.  The stroke would be the “outline” you might see around the font.  However, it is this that we are interested in, as plotters and cutters don’t usually care about fills, only the “outline” which instructs the device where to draw or cut.

The options we need are on the Font panel that appears when you add a text object to your drawing:

InkscapeFontStrokeFill

We want to turn OFF the fill, and turn ON the stroke:

InkscapeFont2

How, we can use Object to Path or even Stroke to Path.

After you do this, you will not see any visible change to your object, but what you will see is that your text panel no longer considers this object as text.  The interesting side effect of this is we can now manipulate our sign as a drawing object.  I’ll cover that in a future post!

You’ll notice the stroke in the above image is very thick. This kinda makes it ugh.. painful to work with, although it doesn’t matter for the cutter, from a visual aesthetics point of view, it seems to be easier on the eyes if we change our stroke size down a bit.  We can select our object and change the stroke style to our liking.  You can un-group the object to work with individual “letters” and add nice effects like sizing, rotation, skew, etc etc.

InkscapeTextStrokeStyle

Now we can send this to our machine through the export plot menu described in my earlier post.

My first sample cut is shown below:

SampleCut1

Next, since it was Valentine’s Day, I decided to play around with this craft foam stuff that I had laying about.  I used a deep cut blade for this.  You can see just at the bottom of the heart where it kinda-sorta didn’t cut all the way through.  I’m actually encountering a little bit of a blade pressure problem at the moment…

 

 

SampleCut2

Here’s a Youtube video of the machine cutting away:

I’ll upload more/better videos soon!

Using Inkscape with an HPGL craft cutter

The latest version (as of this writing it is Inkscape 0.91pre3), Inkscape comes with two HPGL export features.  One, under the file, Save As menu, saves  your design as HPGL.  This is not much use to me at this time.  The second HPGL feature is located under the Extensions menu, Export, Plot …

InkscapeExportPlotMenu

The Plot dialog has three panels of settings, two of which we are particularly interested in.  For my machine, a modified Cricut Expression, I have coded the firmware to set the USB speed to 9600, Software Flow Control (XON/XOFF) an command language is HPGL.

 

InkscapeExportDialog1

We need to change the resolution for X and Y to 400 under the Plotter Settings.  Also, I have noticed that the image cuts in reverse, so checking the two Mirror X/Y axis boxes corrects this anomaly.

InkscapeExportDialog2

Clicking Apply will start sending the data to the machine.

Here’s a video of the machine cutting a complicated design that I downloaded.

 

Inkscape settings for Craft Cutting

My current project involves writing new firmware for a craft cutting machine so that it can speak the HPGL language which is used by a lot of plotters.  HPGL is a very simple language that tells the device to move to some x,y coordinate, put the pen up or down, etc.

The machine I’m working with is a black box system using proprietary cartridges and software from the manufacturer.  Since I only have the machine and no software or cartridges, I decided to explore the possibilities of writing new firmware for the machine so that it can work with simple HPGL output.  The name of the machine I have is Cricut Expression.

The latest version of Inkscape has a really cool plugin called Export -> Plot which allows Inkscape to send my design directly out the serial (USB) port to my machine.

There are some applications that are designed purely for craft cutting machines (Make the Cut! and Sure Cuts A Lot).  Neither of these programs are allowed to operate with the out of the box Cricut machines (Google it).  I have had limited success with them using generic HPGL.  Make the Cut! doesn’t have an HPGL driver.  Sure Cuts A Lot has numerous drivers for various machines, so it was trial and error to find the proper fit (US Cutter SC machine was the right choice).

However, Sure Cuts A lot has an annoying “trial mode” where it cuts horizontal lines through your design.  I find this terribly annoying and I can’t validate my designs are cutting properly because of it.  So I’m being stubborn and refusing to part with $$$ to buy Sure Cuts A Lot.

In the long run, sticking with Inkscape is probably my best option since it is free, has a large feature set on it’s own, and a large user base.  Additionally, it has an open plugin architecture.

So I’m sticking with Inkscape and it’s very nice HPGL Export plugin.

I had to setup the document properties to fit my craft cutting needs.

There are two panels that I needed to configure, under File -> Document Properties.

Essentially, we’re setting up our default page size to match the mat size (12×12), setting the default units to inches, and enabling the grid lines.

InkscapeDocumentProperties1

InkscapeDocumentProperties2

Once you have this setup, the page view looks more usable.  The grid lines have two graduations, one at half inch, and one at one inch.  It kinda looks like the mat that the machine uses.

InkscapeDocumentView