large bearing input needed

[ODdave]

Ok , i am calling on the input of you guys for a project. Knowing how resorcefull people are on here i figured this would be the best place to ask.

I am looking for a very large tapered roller bearing for a 28in turn table i am biulding. I am trying to keep this as low-buck as possible so i was curious if anyone knew where a used one could be obtained???? Or mabye someone has one laying around?

How big are the ones from large semi tractor hubs? Obviously the bigger the better. I am going to try the "local press rebiulding shop" but i doubt they replace them unless they are damaged.

 

[Westech]

your only going to find a 4 maybe even a 5 inch bearing at most..... a better way might be ball bearings on a track. Ez to make and cheap.

 

[ODdave]

West,

Thanks, that was a tought of mine. I will probly check into the caged rollers tomarrow. I would like to use a ball end mill cutter to make a "track" for them to ride in but i dont think the botom plate will fit on my mill , it is 28X36 to allow for the holding fixture. Both plates are .5in thick so i would have material to make the cut.

 

[m16ty]

Could you give a little more info on the turntable? It could be that you don't need as big a bearing as you think or do as Westech said. Semi tractor bearings are not much bigger (if any) than 5-ton military trucks.

 

[Rockcrusher]

look for a lazy susan bearing i made a jib crane one time an i found one but was only like 14 inch in diameter but could get bigger was kina costly the bearings were caged but the upper an lower race was not attached just laid in bottem an top just rode on bearings fafnier i think was name

 

[ODdave]

m16ty,

I am biulding a turn table so i can cut the centers out of hemmit wheels with my plasma cutter. I am just trying to find a faster way than using a mill and my hands are not steady enough to keep the tip square with the piece while cutting a circle. I have a 12in tilting rotary table but DEFINATLY do not want the plaz anywhere around it.

 

[ODdave]

look for a lazy susan bearing i made a jib crane one time an i found one but was only like 14 inch in diameter but could get bigger was kina costly the bearings were caged but the upper an lower race was not attached just laid in bottem an top just rode on bearings fafnier i think was name

Where did you find this? SS? fee bay?

 

[m16ty]

Ok, A semi truck wheel bearing will be more than big enough. That's basicly the size bearing that supports the wheel when in operation and should be more than enough to hold it steady for cutting.

What is the bolt pattern of the hemmit wheels? I'm thinking it's the same as a 5-ton truck. If it is it will be the same as most semi trucks on the road. You could go to a truck junkyard and pick up a front spindle and hub. That would give you the bearings, a housing, and a way to bolt the wheel to the jig.

 

[Nonotagain]

West,

Thanks, that was a tought of mine. I will probly check into the caged rollers tomarrow. I would like to use a ball end mill cutter to make a "track" for them to ride in but i dont think the botom plate will fit on my mill , it is 28X36 to allow for the holding fixture. Both plates are .5in thick so i would have material to make the cut.

All you need for your milling machine to be able to ball mill the channel is a thrust bearing and a hold down stud.

Drill and ream a 1/2" diameter hole in your plate, then bolt the plate and bearing onto your table 14" from the center of the cutter. Climb cut using your ball mill, making the cut about .020 per pass.

 

[m816Buch]

What about the front hubs from a gm pickup...........hub can bolt to a metal plate, with the wheel studs up....make an adapter plate to fit wheel and spin away

 

[ODdave]

Nonotagain,

I will have to look but i dont think the mill is big eough, I know my Index would do it but of corse its not under power. The bridgeport is smaller but I will try tomarrow.

 

[supermechanic]

Caged taper roller bearings form a torque hub (found on most hydraulic excavators) are 10 to 14 inches in diameter.
Find a used one at a John Deere or Caterpillar repair shop.

 

[Nonotagain]

Nonotagain,

I will have to look but i dont think the mill is big eough. I will try tomarrow.

Provided that your not using a tabletop mini mill, a 9X42 or a 9X49 is more than large enough to perform the operation I described.

Crank the "Y" axis all the way out and shift the "X" all the way to one side. If need be you can snug the head up against the column to get almost 18" to the front of the table.,

 

[ODdave]

its a 9X42, Thanks for the info

Supermechanic, Thanks, this was the easy out i was looking for.

Now i dont know what would be a better way to go.

 

[m16ty]

Why do you need such a large bearing? It's not like it's going to be supporting alot of weight.

 

[ODdave]

Why do you need such a large bearing? It's not like it's going to be supporting alot of weight.

I would like it to be capable of 500lb but its more so for stability .

 

[Alredneck]

Dave this sounds pretty interesting, wheres the pics! When you get your jig built would like to check it out!

 

[ODdave]

I will get some pics soon. Just looks like a pile of scrap at the moment.

 

[ODdave]

Ok here are some. Went with the ball mill and the "biuld your own bearing" The top plate and bottom plate are 1/2 inch and the bearing cage is 3/8 with 20 5/8 balls 18 degrees apart. It should work. I only had 4 hours to work on it but i will post more when i get more done.

 

[Alredneck]

Looking good cant wait to see the finished product.

I was thinking this idea would work for a homemade ring mount turret since Army ones are so expensive!