2020 Filament roller for 608 bearings by DracusMage

Last crawled date: 3 years ago

The split pins on fixitnate's version has a problem with snapping - likely a combination of direction of print and the fact that only the top half of the pin holds the weight of the spool. This version has a solid pin to try to add a little extra strength at the expense of the superior retention of the split pin. These won't fall off in normal use, but the bearings are able to pull off more easily (one kept falling off while I was trying to snap it on the rail).The upside is that these can be used with a more rigid plastic without cracking the pins.
This design is fully compatible with the Rollin on 20s roller (bearings are slightly lower, but the spacing is about the same) so if you can print it as a replacement for just one side if you have a cracked pin.
SolidPin-Snug hasn't been tested, but it's not a vast deviation from the "bit of tolerance" version, which was printed (and I'm using). The only difference is I added 0.2mm of plastic to the top of the clip (taking it from a technically perfect 7mm down to 6.8mm space) and I added a chamfer to the inside corner of the clip bits that grab the 2020 rail and give a slightly stronger pinch, which with any luck should wear down a little to fit perfectly. A little file work can fix it if I am wrong. I'll try printing this when I get the chance, but right now I have two rollers that work and a spare already, so I'm going to call it. I'm leaving the other ones because you may not be the adventurous type, in which case you can print one that there is proof it works and fix it. I'll remove the lesser versions if/when I test the theoretically better one. I've also included the Fusion 360 file in case anyone wants to take a crack at it themselves. You just have to promise not to judge me for my terrible CAD skillz when you see how I made it.
The "bit of tolerance" version works almost perfectly. The 2020 clip is a little loose, allowing it to slide freely, which could be a problem. 3-4 layers of painters tape on the top of the rail helps. Alternatively you could wrap a rubber band around the two rollers (above the rail, below the plate) and just use the spool to hold them apart, but that may cause too much friction with the spool on the edge of the pin plate. if you print without supports you will need to remove a few loops of material where the bearing goes, but with a little force the bearing snaps on, and isn't prone to coming off by accident. The clip goes on the rail with a little effort, even if it is a little loosey-goosey once it's on.
This "too tight" version has -no- wiggle room. You will need a file or sandpaper to make this fit anything. I will fix that soon. For now, you will need to remove some plastic from the bearing retention disk, a little from the bearing shaft, and a lot from the 2020 clip part (the bit that has to go over the top of the 2020, but inside the edge of it). Rounding it a bit helped, and printing at a lower infill with fewer side perimeters would also help (increase the springability of the clip). The upside is this allows you to get a perfect fit, if you have a lot of patience and some good needle files. The 2020 clip is still loose though.