I’m a big fan of my Snapmaker 3D printer. I love the fact that, unlike many of the me-too clones on the market, it’s solidly constructed with lots of metal. No exposed drive belts, instead using linear actuators. Basically, it’s a pretty good piece of design and engineering.

However, one thing that has always bugged me is the kind of crappy holder for a spool of filament. It’s literally a rod that sticks out to the side, with a screw in end-cap to (try and) make sure the spool doesn’t fall off the end. It (mostly) works, but it’s a bit naff and feels like an afterthought.

So, I decided to do something about it!

There were a couple of challenges to overcome:

• I wanted to keep the spools centred if possible, to reduce the amount of drag when feeding while printing. The poor feed gear in the print head has to do a lot of work to overcome the mass of the spool hanging off centre!
• While they seem to be close, it appears that there’s no formal standard between different brands of filament for the specifications of the spools. The inner diameter can vary, so whatever is holding them really needs to be adjustable.

The solution I came up with is a threaded, hollow rod that slides over the existing holder. It’s a close fit, but not so tight that it can’t rotate easily. Onto that rod I screw on a couple of cones – narrow end inwards – that will centre on the hole in the spool and hold it in place. The cones have been slightly modified to provide finger grips to make it easier to loosen and tighten.

STL files are available for download from Thingiverse.