None of the cups on thingiverse fit my springs. not sure if mine are different from the wanhao ones?? they were all too small (by a lot)
so I made my own. I had to print them at 103% (on x and y only leave z at 100%) They NEED to fit LOOSE and not restrict the springs or they will inhibit them from "rising" on fine adjustments. so clean up the inside also if your printer is a little sloppy.
These will keep the springs from "tilting and bending" which will throw off your bed level.
I made them 7.3mm tall which is a little smaller than the spring fully compressed so they won't interfere with the movement or compression of the spring as long as they fit LOOSELY.
both holes are also beveled though you won't really see this unless you print at high resolution.
Monoprice Maker Select i3v2
infill is 100% but its small enough that I don't think infill settings will matter.
Make sure the spring is a clean loose fit. no wiggle but also no resistance. use a knife to clean the inside wall up as well. put the spring in and compress several times make sure no resistance. Your ready to go. going 104% might remove the need to clean up. just make sure you change both x and y equally and do NOT change z 7.3mm is the highest you can go without interfering with the ability of the spring to compress fully.
I just went into tinkercad and started making cylinders (I imported my own custom cylinder from 3ds max to bypass the low polygon nature of parts made IN tinkercad.
I use a parabolic cone to make the bevels.
the hardest part was the calculations to place the parts relative to each other before cutting. there is no "center" option in tinkercad :-)