Thread: Cheap bushing/bearing options for an 85mm shaft?

I'm in the process of designing a tube bender and am trying to find a cheap option for the shaft bearings/bushings. The plan is to make something very similar to a jd2 model 53 except that instead of using the hydraulic cylinder pushing through a ratchet arrangement I'm going to wrap a leaf chain around a drum and pull to get the main die to spin.

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Everything looks pretty straight forward except the the bearings for the shaft. I figure the shaft needs to be around 85mm diameter and the bearings need to cope with radial loads around 20t but I'm having difficulty finding an inexpensive option to do this. Ball bearings dont have the capacity, roller bearings are a least a couple of hundred each, bronze stock was by the foot and about $500 and the local bearing place didn't do bronze bushes up to that size. Bronze bushes appear to be available overseas but still look pretty pricey.

Given the limited use it will see I was even considering a lubricated steel on steel bush but I thinking that is just asking for trouble. I'm not so worried about wear as I am about it galling and welding together so maybe a cast iron or hardened steel option might work instead and not have this issue. Thoughts??

Try pricing them cast. May be a cheaper option.

yeah was just looking around a bit more and found a 3.25"IDx3.75"ODx6"HIGH cast bronze bush for $60 bucks from ASB Bearings in the states. As long as shipping isn't extortionate that might be the go. Crisis averted...

A tough steel pin in a tough steel bush/housing will be OK for that purpose. In support of that I submit that the Hudson Motor Company for many years used steel kingpins in steel bushes and they worked just fine. In fact they still work just fine.

Steel shaft in a grey cast iron bush should be fine too. Flocast comes in tube i think? Just machine your own to suit.

Ew

Given the speed and movement needed secondhand truck or trailer bearings would be ok.
Truck mechanics would be a good place to look. I can measure /find /send some if you like.
John

Originally Posted by bob ward

A tough steel pin in a tough steel bush/housing will be OK for that purpose. In support of that I submit that the Hudson Motor Company for many years used steel kingpins in steel bushes and they worked just fine. In fact they still work just fine.

I have a piece of shaft hanging around I could use for this already but im pretty sure its just low carbon steel. Case hardening is not something i've tried before so not sure how much successful it would be on such a thick section.

Originally Posted by Ueee

Steel shaft in a grey cast iron bush should be fine too. Flocast comes in tube i think? Just machine your own to suit.

Ew

This could be the go if all else fails...I have an old tractor counterweight that might just be thick enough to cut the bushes from too

Originally Posted by rascal

Given the speed and movement needed secondhand truck or trailer bearings would be ok.
Truck mechanics would be a good place to look. I can measure /find /send some if you like.
John

Cheers john. If you could have a look and measure some it would be much appreciated. Do these tend to be a standard size or do they vary?

Redgum and steel were another bearing combination used long ago.

Michael

218210 cup /218248 cone is a widely used set o d is 147mm, i d is 90mm, thickness is 40mm roughly.
212011 cup /212049 cone 122mm 66mm 38mm
There will be many others in this size range.
How flexible is your 85mm dimension?
John

I,ve found that old farm machinery is a good source for larger shafts, bushings and many other useful bits.
You are in a country area, it might pay to have a look in a few farmers junk piles, that's if the scrap guys havn't got it already.
I've got some bronze bushes about 63mm ID 75mm OD, 150 long if they are any good to you.

Originally Posted by rascal

218210 cup /218248 cone is a widely used set o d is 147mm, i d is 90mm, thickness is 40mm roughly.
212011 cup /212049 cone 122mm 66mm 38mm
There will be many others in this size range.
How flexible is your 85mm dimension?
John

I have a piece of shaft that I want to use that is about 90mm diameter so a 90mm bearing might work perfectly.... just need to check the size of the shaft properly. I've been a bit conservative with sizing of the shaft because I'm not sure of the material but it could probably be reduced to 75mm at a pinch... bigger is obviously better though. I might go a pop into the local trucking place and see if they will help me.

Originally Posted by BRADFORD

I,ve found that old farm machinery is a good source for larger shafts, bushings and many other useful bits.
You are in a country area, it might pay to have a look in a few farmers junk piles, that's if the scrap guys havn't got it already.
I've got some bronze bushes about 63mm ID 75mm OD, 150 long if they are any good to you.

Thats a very good idea... I had never thought about finding bushes that way... I do see a lot of scrap trucks in the area so hopefully there is some stuff left for me to pick over. Thanks for the offer but those bushes are quite big enough.