Chamfer sled for block planes

A chamfer sled, attaches to sole of plane with magnets.  Easily adjustable with threaded knobs.  

To set the chamfer size turn the knobs toward one another or apart to adjust the gap.

I used 8mm x 3mm magnets, mine press fit, but you may wish to use a dab of CA glue. 

the screws I printed vertically with a brim, otherwise no supports are needed for any of the parts. 

A couple of other versions have been added,  since the press fit was really tight and there will be variations between printers, I've included a version where the holes are loose 8.5mm to fit the 8mm magnets.  They will need to be glued in place in this version, but there should be no worries about fit.   I've also included an o-ring groove concentric with the magnets, I'm thinking this will prevent the sled from sliding as easily on the sole of the plane.  A bit of movement doesn't really matter, but if the sled stays totally stationary I think it''ll be nicer to use.  The intended o-ring size is 14mm OD 1.5mm thick. 

The other version is with unequal chamfer of 30° and  60° rather than the usual 45°

Edit2: a version to fit 10mm magnets, leaving holes 10.5mm to allow glue squeeze out has been added.  This version has grooves for optional 16mmx1.5mm o-rings too.