2 Piece Large Bed Leveling Knobs

This is a large two piece bed leveling knob for 3D printers that use M4 hardware for suspending the bed, and that have room for such large knobs.  I'm presently using them on a pair of Ender 3 Pro's, my CTC A10s which is a CR-10 knock-off, and my Anet A8 Plus.  Be advised that these only fit my Anet A8 Plus because my display is mounted on the left side of the frame completely out of the way of the build area.  The front wheel on the right side would otherwise bump the display if it's in the stock location.  I find it much easier to tram with precision using large knobs.  These knobs will only work with machines that use M4 screws for suspending the bed, and each of the 4 knobs will need a M4 nut to be complete.

I usually like to print the outer wheel portion in a color matching the machine and I print the centers with the spokes black, which makes the centers look nearly invisible against the black surfaces where my printers sit.  The set I'm about to install on my Sunlu T3 is a little different.  I didn't realize until I'd already printed the outer portions in blue to match that machine, that I didn't have any black filament.  I found some light gray and thought “Go Lions!” :)  I think it's a good color combination.  The assembly photo's will be the blue/gray knobs I'm making right now…

I print these as oriented in the STL.  I don't use supports for the outer wheel portion, but do use supports “to build surface only” for the inner hub portion.  Those supports are very easily removed and will prevent a nasty birds nest from occurring at the interface for the M4 nut.

After removing the support from the inside part, I typically use a M4X10mm screw and flat washer to draw the nut into the cutout from the top side.  Once the nuts are in place, I place a dab of super glue gel at each of the three cutout positions in the outer wheel, then press the inner part into place from underneath.  I tried to include many photo's to illustrate how these things go together.

This is the third, and hopefully my last iteration of this design…

Version 1 was a two piece design as it had a cap to make the nut captive.

Version 2 did away with the part that made the nut captive, and reduced the surface area that makes contact with the bed support.

Version 3, this version goes back to a two piece design that must be glued together, but instead of gluing a cap for retaining the nut, the two pieces are the center with spokes and an outer wheel.  Printing both parts of this version in the same color would result in a part that is indistinguishable from version 2.  The purpose in splitting the center from the outer portion is for using two different colors.

Most machines I've installed this part have the outer wheel portion printed in the color I used for the bulk of printable parts for a given machine, and the inner part where the nut installs are printed in black.  The result is IMO creates a neat affect that makes the outer portion of the wheel appear as though it's suspended in mid air as the black centers blend in with the black surfaces these machines rest upon.

I made these 8 months ago and never published them because I was thinking they weren't different enough to justify publishing, but had a change of heart today when I wanted to print a set for a new machine and I couldn't find the STL for the center piece.  After taking the time to recreate the missing part, I decided to go ahead and publish this so even if nobody uses these, I'll be able to find them the next time I need them.  :)