Which plastic for bearing surface- Cane Grinder

[Olddaddy]

I picked up a set of cast iron rollers from a very old Cane Mill today. Originally I suspect they were greased with something and the shafts turned in the "bearings" easy enough. They don't turn fast or for very long when you are juicing sugarcane to make syrup. I'm thinking of making some plastic "bearings" to install between the shafts and caps to eliminate the need for grease. The shafts are 3 1/2" diameter, so if its a tube it would be a big one unless there is sheet soft enough to form to the radius of the caps.....Ideas? Advice?

 

[Ulma Doctor]

Delrin and nylon would be right up that alley
both are easy to machine

on another note,
i have heard of folks melting down old plastic milk jugs and creating HDPE slugs for machining.
( i very much want to try this )
no special tools are required.
the guy cut up the jugs into ribbons and placed them in a steel pipe crucible mold and a 225°F (109°C) oven
it will take a few cartons, small pieces are best.
let it soak in the oven until melted and remove after the plastic has formed a cylinder
let cool until the slug contracts (or devise a hinge in the mold) and remove the slug
after the shootin' match solidifies, you are ready to machine at will

to make a bearing,
you could devise a pipe inside a pipe form to create the center bore, to eliminate having to core the center out

or you could go the old fashioned method of buying sheet material and heat it up slightly until pliable enough to form over a pipe mandrel.
you may need to do a bit of math to get the correct cut on the sheet, but it is well within reach

 

[benmychree]

I would think in the direction of a very hard wood.

 

[Olddaddy]

You guys! So quick and smart, all at once!!! I like the idea of Delrin or Nylon.....Hard wood, well maybe. Perhaps some Lignum Vitae? Purple Heart or Green Heart? I do have some very old and very hard heart pine.....now there's a thought!

 

[mmcmdl]

on another note,
i have heard of folks melting down old plastic milk jugs and creating HDPE slugs for machining.
( i very much want to try this )
no special tools are required.
the guy cut up the jugs into ribbons and placed them in a steel pipe crucible mold and a 225°F (109°C) oven
it will take a few cartons, small pieces are best.
let it soak in the oven until melted and remove after the plastic has formed a cylinder
let cool until the slug contracts (or devise a hinge in the mold) and remove the slug
after the shootin' match solidifies, you are ready to machine at will

Oh no ……………………….not ANOTHER project to try out .

I end up with 100 or so milk / water jugs every time I go up to the property . I can make up a makeshift pipe mold and throw it on the fire pit !
I won't have to worry about cutting it up hough , the .338 Win Mag takes care of the shredding .

 

[f350ca]

White oak makes a very good slow speed bearing, but does require some lube. Would think vegetable oil would suffice.
Lignum Vitae is an exceptional bearing material when run wet. Still used in water turbine bearings, but wouldn't be required here.

Greg

 

[matthewsx]

I picked up some kind of plastic tube around that size from a horizontal boring crew. I think it was for natural gas, a little big for my lathe but interesting nonetheless.

John

 

[benmychree]

I made a set of bearings for a vineyard disc plow with lignum vitae many yeas ago for a guy who provided the material, it machined just like a plastic, kind of like delrin, but not so frizzy --- fun!

 

[Jubil]

White oak makes a very good slow speed bearing, but does require some lube. Would think vegetable oil would suffice.
Lignum Vitae is an exceptional bearing material when run wet. Still used in water turbine bearings, but wouldn't be required here.

Greg

Isn't lignum vitae toxic? Seems I read that it is.
Chuck

 

[Richard King 2]

check with these guys. They have engineering help desk and super web site. I would think Nylatron would be good. It is nylon impregnated with graphite. My Old Ford 3 point disc used wood, but it wore and cracked. https://www.tstar.com/