I want to make a very large CoreXY type of pen plotter. The plotter will work on an area at least 4’x8’.
I know there are gantry robots for this sort of thing. But, I am hoping to avoid must of the physical structure.
Here is an image from CoreXY.com
Note that a lot of the structure is simply the back plate, used to mount the pulleys in the corner, plus the horizontal traveling piece. In my case, I am hoping that the pulleys in the corners can simply be taped to the floor. I think there should be a piece of wood (just 2x2) along the long side, to serve as a guide, to avoid the horizontal traveling piece sliding side-to-side. That horizontal traveling piece would be perhaps 52" long so it has some overhang to ride along the long piece.
My issue is that I need two belts 27’ long for the 4’x8’ version. And I would like the option of adding substantially to that size. Needless to say, standard timing belt would be too expensive.
One option, is to use any kind of non-stretching cord or thin wire, and at the motor the pulley rolls-up the cord it is taking in, while simultaneously feeding out, the other direction. Both ends are just anchored in the pulley.
Another option I am looking at now, is the kind of chain with plastic beads molded onto it. They are used in the clutch-type roll-up blinds. It costs around $6 for a 32 ft length. I can get the replacement chain-clutches for around $9/ea. Though, I don’t know for sure if I can modify it easily to mount onto my drive motors. But, there are 3D Printable models.
Any other ideas?