Bed Level Hint Knobs

After seeing https://www.thingiverse.com/thing:3597297 I thought that would be good as a bed level knob for my ANET A8 Printer and simpler than some Jimmy Cricket Wellies and set about on this simple design.

This design has a U(p) and D(own) etched into the arrow heads to show the direction of the Heated Bed when adjusted.

I only use a wingnut, so didn't add a hexagonal hole (maybe a future revision).

I only printed and replaced one of my existing knobs, but you could do more if you c