Replicator bed level jig for dial gauge with 20x8mm shaft imported original into sketchup and re-modeled for metric guage with 8mm diameter 20mm length shaft. Gives about 3mm of movement on bed so might move the collar up in the shaft hole to lessen the pressure on the bed. uploaded a version 3. stronger magnetic sockets and re-designed to print without support on its back.printed with 2 shells and 25% fill I will do another with 3 shells as I got a crack when inserting the magnet in the plain end. Magnets are same 1/4" x 1/4" rare earth. ebay �£5 for 18.