One problem I have consistently noticed with my filament is that every time the printer pulls some filament in, the spools rolls and keeps doing that until it falls of the table. To prevent that, the holder has a curve on the back which should stabilize the spool every time the printer pulls it in. This holder is very simple. The spool fits in the curve of the object which helps it spin easily and feed the printer without getting stuck. This print should print well, though it may take a while. Print 1 of each base and 4 wheels.