Round bearing for square tubing

[gigag04]

pervus bearing here in Dallas has all kinds try them

http://purvisindustries.com/locations.html#" onclick="window.open(this.href);return false;

I too thought of purvis first.

[flb_78]

http://www.thebigbearingstore.com/disch ... aring.html" onclick="window.open(this.href);return false;

Biggest is 1.5" square center in a disc bearing, but they have many other styles.

[papajohn1964]

Why does it have to be round? How about a square with some sort of rollers on each side? May be easier to build or find. Or maybe instead of rollers just line it with that white Teflon stuff. Just me thinking outside of the circle!

Edit: I thought it was to raise an lower the mast. You could still line a piece of pipe with Teflon and get the rotation and up and down.

[Charles L. Cotton]

Thanks folks, but this is turning out to be far too involved to be useful to the target audience.

I appreciate your input.
Chas.

[texasmusic]

I've only seen them on old PTO augers, might be able to salvage one and pick a tube to fit.

[Oldgringo]

Aah, a square peg in a round hole? This has been an age old curiosity of sorts.

[sjfcontrol]

And here I thought he was designing some kind of universal, computer-controlled machine-gun turret...

[KD5NRH]

If you're not looking for super-low-resistance, a Delrin 527UV bushing turned to slip fit inside a sleeve made from standard PVC pipe is pretty smooth moving and more weather resistant than anything metal. The Delrin should hold up pretty well, and the PVC is dirt cheap to replace if it fails after a year or two.

Smoothest bearings I ever managed to homebrew for a telescope were Delrin scraps running against PVC for the elevation and against a junk CD for the azimuth. Felt almost like ball bearings, but with just enough resistance to hold position once the scope tube was balanced and the CD leveled.

[sjfcontrol]

'Ya guys do realize this is a thread from four years ago, right?

[KD5NRH]

'Ya guys do realize this is a thread from four years ago, right?

At the rate most ham projects get done, he's probably still waiting for a good deal on the feedline.

[cbunt1]

'Ya guys do realize this is a thread from four years ago, right?

At the rate most ham projects get done, he's probably still waiting for a good deal on the feedline.

I was about to withhold my input due to the age of the thread, but you make a very valid point!

So, since I'm no longer withholding...I think the bearing in question is fairly common on agricultural equipment in the form of PTO shaft bearings and carriers. Many a post-hole auger or brush hog I've encountered had one -- but I'm not sure whether the shafts were as large as 2".

Of course, for a mast/rotator that's not under a load (at least nothing like a 540RPM/50HP load) a reducer could make fitting it all together easy enough.

Tractor Supply, a John Deere or Case dealer's parts department might be a good starting point.