Wheel Dollies

1930 said
How does one make a cheap caster? I mean roller bearings are there. My only guess is that the bearings become heavily pinched when under heavy load stopping them from rotating.

That does not explain why they are difficult to maneuver when not under load when they are used in unison with other casters.

Junk metal that isn't round for the balls and the other surfaces not being machined smooth for the balls to rotate on.

I have a pair of Gojacks and they work fabulous. I bought the pair very reasonable at an auction and had to replace a couple of casters. The casters cost me around $70 for a pair but they are worth it for as good as they work. I would love to find a second pair at an auction but it hasn't happened yet.

If you look at the Gojack picture you will see that the wheel isn't offset from the center pivot as much as the casters you posted.