Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3367545.

I remixed Redsalamander's pressure fitting fix. Mostly just made them a bit bigger. I enlarged the top lip to make it easier to grab. I was having trouble with the originals breaking at the top of the arms. I did not include different thicknesses because I figured it could be scaled in the 'Z' direction to accommodate. These sizes worked well on my Ender 3 that was bought Nov. 2018.