A1 mini plotter conversion
Recently, I made some stickers, but was not very happy with the price nor quality. So as any good maker, I decided to (reluctantly) buy a nice printer (IX6850 for anyone wondering) and build my own plotter.
Because I wanted to only cut out stickers with it, it didn't need to be very large at all, and the one machine that I can make move in basically any way, my Bambulab A1 mini, was the perfect candidate.
Together with Laura, we started to design a mounting solution for the plotter knife holder I bought. It should be pretty easy to mount, somewhat lightweight and not interfere with the normal operation of the printer when the knife is not mounted. The knife holder needed to be held in place pretty tightly, but also should to be removable without tools. The knife itself needed a spring to put even pressure on the paper.
The modeling was done in FreeCAD based on a reference photo and measurements of the knife holder and print head.
The first version was a bit to tall because the image was not quite parallel, but it did fit well enough to iterate on the spring, which needed three iterations in total to get the right force and increase the bottom size. The second version fit perfectly and with the mounting holes in the same place, the spring also fit perfectly.
Work Holding
Another challenge was the work holding. The print-bed is smaller than an A4 sheet, so to not have the paper catch any stationary parts, it needs to be trimmed to size.
There are magnets embedded in the print bed, so magnets can be used to hold the paper down. This works ok, but it's really easy for the paper to shift.
A better idea is to make a custom sheet metal frame to hold the outside of the paper on all sides and reference the paper to the edges of the print bed with pre-measured offsets.
The actual solution
Unfortunately, I was not able to solve the work holding problem in the timeframe that was allowed to me by my attention span, and so I just ended up buying a Portrait 4. Their software is also super easy to use for making stickers of which I've now made quite a few.