Ben Lucy

Hey, thanks for the comment. There are two stepper motors, they are in an hbot configuration. If you Google that then you will find a diagram explaining it. The two stepper motors both turn at once to move in either x or y... A diagram will explain best

Thanks! This would actually take quite a bit of work for a few reasons:1. The gantry isnt very rigid so there is unwanted movement. For drawing straight lines this isn't a problem because the movement happens immediately at the start of each line, so all the lines are aligned. For a circle it might have more of an effect, so the carriages would need a little redesign to eliminate the movement.2. The advantage of this plotter is that you don't need a computer, but that's also a disadvantage. If you want to draw a circle then you need to overwrite the arduino specifically to do this.3. You'd need to redesign the brush holder so that the brush is vertical to the page, so that the direction of movement doesn't affect the line thickness.

Thanks! Yep I've now added the Autodesk Eagle files to the github (the '.sch' and '.brd' files) which you should be able to import into Altium