dusty wrote:Honest question.
Distance off the floor (clearance). Can you really tell by measuring the cam. Yes, you can tell the difference between the two levels (as caused by the cam) but does that same information tell you anything about distance off the floor.
There should be a direct correlation between the cam lobe height and piston movement which should equal caster movement after caster stem has bottomed out in the piston bore. The rest to low lobe difference is 9/32" which allows the caster stem to clear the stop at the end of the bore 1/32" as the legs rest on the floor assuming 1/4" leg clearance at the low lobe position.
Granted these are 'nominal' dimensions and will vary in practice due to various tolerances.
The older casters(both metal and plastic etc.) had no swivel bearing and thus the stem rotated within the piston bore. The new 3" casters do have a swivel bearing and I ASSUME the piston bears against the top of the bearing race rather than against the top of the stem. Regardless the original floor clearances should be the same if the casters are mounted correctly.
Again the most critical dimension is the caster(stem/race/whatever) clearance that allows the total weight to rest on the legs at the 'rest' position.
P.S. Realize floor clearance will decrease as the casters wear to a smaller od.