Fix grinding of big wheel axle/hobbled bolt

[hlavaatch]

Fixed hub clearance for 608 bearing on the big extruder wheel axle/hobbled bolt in extras/gregs-wade-v3.scad to stop the bearing hub from grinding the wall and make the axle free to rotate.

[hlavaatch]

Ah i see, so the hole is plugged intentionally? And the user is excpected to dig it out? That sucks. I can do it better with inhole support... I'll do it

[hlavaatch]

It would be best to factor out all the explicit supports and make them optional, to not pollute the final shape with it...
Let people use whatever support they want/need...

[hlavaatch]

Okay just did a test print with my "inhole support", and it turned out great.
Its sort of a puck with a slot on bottom and a crown of thin support beams that the ridge can be laid onto. When printed I just inserted a table knife into the puck slot and twisted and it snap off cleanly. Any remains of the support lines are easily cleaned off with a flat screwdriver.
I will modify my patch to include it later when I test similar approach for the motor mount holes so that they dont have to be plugged as well, factor out the supports and make them configurable (none/bridgy/inhole)