Do you guys use bearings for your filament spool?
Personally I do not.
I take it you mean bearings to roll the spool on (cradle style) or do you mean to center it on a spooler rod? Either way I don’t use bearings. I just use printed adapter hubs to go from the spool reel diameter to the spooler rod diameter. Typically 52mm to 8mm.
I’ve got my filament sitting flat on a $9 lazy susan on top of the printer, and it has the loudest bearings you’ve ever heard. 
Yes.
When I tried using bearings, the spool turned too freely and caused the filament to fall off the sides of the spool. I don’t even use anything now, I hang the spools on a round 3/8" steel rod - no adapters, no bearings, no tangles…
Good point. So I’m not going to use bearings right now Thanks!
@Alan_Thomason I saw similar issues in that as the head would travel from near extent to the far side on the bed it would yank the reel and keep unspooling or as the reel got low the the natural coil of the filament would unspool like a slinky on it own just sitting there. I liked the low tension the hubs provided but the free coils bugged me so I put in an 18" piece of free floating teflon tube (Bowden tube?), fed the filament through that, and got the best of both worlds.
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@Jeff_Parish I did something similar as well - I printed a plastic clip for the frame rail (I have a Rigidbot as well) that held a short piece of tubing. I ditched the little clip when I bought a longer rod and moved my spools to the back instead of the side of the printer. This way when the print head moves, it pulls less filament off the spool.
@Alan_Thomason Yep, RigidBots and RB3’s are my work horses. Very good machines. I remember your frame clip. Nice simple design.
Moved the spools to the back for a bit to test that orientation but in my situation it blocked access to the printers on the back tier and on the Bigs the side to side travel was enough to pull filament of the side of a new spool. Switched back to side mounted. Good thing these are versatile machines with lots of ways to solve problems. 
The main point is to stop friction that causes your filament flow to be affected. Believe it or not, it can manifest itself as small fluctuations in extrusion rates, which can have a visible impact on print quality.
Yes. I’m using a bearing and post from Harbor Freight item # 94050.
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