What kind of bearing / bush / flangey thing would I use to travel on solid rod?

[skotl]

Lets say that I have a fixed structure that includes a solid rod (for the sake of argument, 25mm or 35mm dia steel or aluminium)

I want another assembly to be able to travel up and down, using that rod as a horizontal stay - maybe two rods for rigidity. Note that the second assembly has its own tower, rack and pinion, etc. (it's the head on my mill).

What kind of thing could I put in the sliding object that would help it travel up and down the rod without binding? I've had a look on the bearingboys site but can't see what I need - it doesn't seem like a bearing, as they would normally work in a coaxial fashion - is it just something like a copper bush?

(note that I don't want to use a leadscrew rather than a smooth rod as the mill head structure already has its own rack and pinion system - the intent of all of this is to offer some rigidity to a round column mill so that it stays in place horizontally as it's raised and lowered)

 

[pressbrake1]

Here

 

[hotponyshoes]

Linear bearing might be the search term.
A flanged linear bearing might be the ideal thing for that.
I think I have got a few sizes if you want me to see what they are?

 

[skotl]

Here

View attachment 301202

Linear bearing might be the search term.
A flanged linear bearing might be the ideal thing for that.
I think I have got a few sizes if you want me to see what they are?

Aha! Yes - that's the chaps! Obvious in hindsight, linear being orthogonal to coaxial!

Cheers gents and, yes please, @hotponyshoes - I don't have the rod yet so it's either a case of buying the rod and bearings to suit, or the bearings and rod to suit!

 

[daleyd]

I’d say a linear bearing or bush of some description - depending on the speed of operation and tolerances required amongst other things.

Bearings would have less friction and probably have tighter tolerances, whereas bushes have the advantage of being able to be knocked up at home to custom sizes in a lathe fairly easily, if required.

 

[merryman]

I suspect those ball races will be for use on hardened steel rods. Bronze, brass or nylon would be better for softer steel. Definitely not copper for a bush, and aluminium for the rod? Probably not a good idea either.

 

[Bullet2012]

As long as it’s moist the solid rod will be ok

 

[skotl]

I suspect those ball races will be for use on hardened steel rods. Bronze, brass or nylon would be better for softer steel. Definitely not copper for a bush, and aluminium for the rod? Probably not a good idea either.

Fair point on the rod. Steel will be easier for me to fix, too.

 

[hotponyshoes]

I have got these in either 20mm or 25mm?

drylin® R pillow block FJUM-01

drylin® R pillow block FJUM-01

www.igus.co.uk

 

[Agroshield]

Have a search for 'round linear rail'. Used a lot by home CNCers and available from the girl from ChinaBay (not Shirley, the girl from Tiger Bay). Random example: https://www.ebay.co.uk/itm/132644534766 (2 x 1m of rail and four bearings for about £60. Greater than 20mm dia. is a bit less common).

Any old piece of steel rod might not be too successful: it needs reasonable standards of diameter, roundness and straightness and also hardness to work with the bearing for any length of time.

 

[frank horton]

personally I'd be using st/steel for the rod, actually tube...(water pipe, any size u want)).made very accurate...and reasonably priced..in a shed inviroment steel will rust...
linnier bearings are great but need prtection from flying cr@p....

 

[skotl]

Have a search for 'round linear rail'. Used a lot by home CNCers and available from the girl from ChinaBay (not Shirley, the girl from Tiger Bay). Random example: https://www.ebay.co.uk/itm/132644534766 (2 x 1m of rail and four bearings for about £60. Greater than 20mm dia. is a bit less common).

Any old piece of steel rod might not be too successful: it needs reasonable standards of diameter, roundness and straightness and also hardness to work with the bearing for any length of time.

They look really interesting - cheers

 

[skotl]

I have got these in either 20mm or 25mm?

drylin® R pillow block FJUM-01

drylin® R pillow block FJUM-01

www.igus.co.uk

Thanks for that - lemme think about it, rods, etc.

 

[500e]

Got some SS hydraulic pipe 0.679" dia 100" wall

 

[Bladevane]

Cheap Chinese linear bearings might do the job but they are terrific at releasing the odd ball or two when threading the rod into the bearing. I have heard that you can live with a couple of balls missing but more than that could be a problem. Even Misumi bearings can release balls if roughly handled.

 

[Mr Roo]

Aha! Yes - that's the chaps! Obvious in hindsight, linear being orthogonal to coaxial!

Cheers gents and, yes please, @hotponyshoes - I don't have the rod yet so it's either a case of buying the rod and bearings to suit, or the bearings and rod to suit!

i’ve the majority of a length of 35mm bright steel round if you want a piece?

 

[JEZGUZ]

Are you modifying a Rong Fu or similar mill/drill?, there's some examples on yt . Thinking of doing the same to mine , just bought a 3mtr length of EN8 which might do the job.

 

[skotl]

Are you modifying a Rong Fu or similar mill/drill?, there's some examples on yt . Thinking of doing the same to mine , just bought a 3mtr length of EN8 which might do the job.

Yup - exactly that

 

[skotl]

Are you modifying a Rong Fu or similar mill/drill?, there's some examples on yt . Thinking of doing the same to mine , just bought a 3mtr length of EN8 which might do the job.

Well, there's something I hadn't thought of - simply bolt the rack to the round column...

 

[JEZGUZ]

I'm thinking I might use an old fork stanchion instead of the bar, time to get the tape measure out then. Better check they're not bent first though.