YACQ (caster question)

[cbrown]

Has anyone used ball casters (like a roller bearing mounted facing down) on shop equipment? Do they jam up with sawdust or do they work OK on a not-quite-immaculate concrete floor?

I have successfully installed my $15 Herc-U-Lift+ on my BT--less trouble than I had feared--and it works great, but it makes the saw 5/8" lower than with my previous mobile setup, so I need to lower my router table (currently on 2" casters with 2.5" total height) a bit to continue using it as an outfeed table. The router table has rubber feet that screw down to lock it in position, so the casters don't need to lock. (I could also add a sheet of plywood with a dust collection port between the BT and the stand to jack up the saw, but I had wanted to switch the router table over to all 4 swivel casters or the equivalent anyway to make it easier to move in tight space.)

Thanks for advice.

--Christopher

[mpc]

Never tried roller balls as casters... but my first gut reaction is that they tend to be hard metal and would mess up almost any floor other than concrete. Plus the exposed diameter is small so they'd snag every crack in the floor.

mpc

[big tim]

I tried to use those as part of a system that would slightly lift my workbench so I could move it around a bit(I have a very small shop in the basement). I decided against using them because the load is distibuted over a very, very small area. They actually left grooves in the floor of the shop, mind you the bench was over 300lbs. I ended up using casters on a custom lift system I designed and built myself.

[LCHIEN]

Because of the ball all the weight is concentrated on a very small area (nearly a point contact)
giving a large number of pounds per square inch, the pressure is very high and can damage the floor. A caster carrying 100 lbs on a .01 sq in pont of contact below that ball will have 10,000 pounds per square inch!

A 1" wide wheel spreads the load over a line about 1" wide. vastly lowering the pressure. A rubber or soft plastic wheel will flatten and deform some making the footprint of contact 1" by perhaps as much as 1/2" decreasing the pressure even more than a hard wheel. The same 100lbs over .5 sq inches I just described will be only 200 pounds per square inch.

A wide wheel and a larger diameter wheel and a softer wheel will also have larger foot print if you want to avoid loading the floor and damaging it.