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.
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.