bronze linear bearings

[jarr88]

are broze berings good if it is all you can get

[Mcgyver]

there is nothing at all wrong with plain bearings, they are used all the time in a wide variety of applications, like the crankshaft in your car) The bronze sintered ones are for a press fit in an accurately reamed hole. in other words they are slightly oversized but become compressed with a press fit. The tolerance between bearing and shaft can be controlled by the size of the press fit hole - machinery's handbook tells how to calculate. This does require a correspondingly accurate shaft, i.e. ground precision shafting

[swarfmacdaddy]

If your using them on an axis, ala rods like on a z axis, your going to hate life trying to get them alingned. Get a night job and by linear bearings, or stalk ebay. You wont regret it.

[spalm]

I think you should supply more info as to where you want to use them.

I have them riding on ¾” Thompson rods for the Z on my hobby machine. They are cheap but I believe I was lucky on getting the alignment just right. I did not use any compression as mentioned by Mcgyver, but I ordered a tight set. They work quite well, but oddly enough, I have to hit them with WD40 every now and then. They are not very forgiving if you have any skew in your rods. Seems to me they would not work to well for a horizontal application unless you are really really lucky.

Swarf probably said it right.

Steve

[Vaughan Sage]

I put an accurate dowel inside the bronze bush when pressing it in to avoid excess ID collapse when pressing toight the OD. use 3 bushes inside of 4, at least the twist alignment reqd is then much less the two bushes can be a long way apart & you can have 3 pillars to support this longer guide rod, so getting shorter guide rod length tween support >> much more rigid