General welding questions that dont fit in TIG, MIG, Stick, or Certification etc.
kiwi2wheels
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    Sun Feb 17, 2013 10:27 am

With an interference fit on the OD, go for a bearing with a C 3 tolerance.

Even if you use a slip fit inner/outer, the C 3 will give better life.
Artie F. Emm
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    Thu Jul 24, 2014 7:53 am

Wow! Thanks for responses. At the risk of exposing my ignorance... I'm glad I posted this question. The lathe work is something I've always wanted to try, and I'm finding it interesting and fun- and gaining more and more respect for the people that do it well.

These wheels are part of a 2x72 belt grinder build, and since I've seen 1616zz bearings in use on other machines it seemed reasonable to use them. The bearings accommodate a 1/2" axle so I plan to use a 1/2" bolt; I drilled a 9/16" hole through the wheel so contact would only occur between the bearing and the bolt. The "well" for the bearing will center around the axle hole, and I thought I would leave a raised ridge around the axle hole so that surface of the wheel would contact only the inner ring of the bearing. Is that a good idea, or is it better to use a spacer on the bolt?
Dave
aka "RTFM"
bruce991
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Hope your looking at 10.9 grade shoulder bolts and not soft hardware grade bolts or you will buying bolts by the pack.
electrode
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    Wed Nov 02, 2016 5:02 pm

Rupes wrote:
So how you do you machine up an accurate crown on an alloy wheel on a lathe
Use the compound or a taper attachment if your lathe has one and a good tool bit. ;)
electrode
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Artie F. Emm wrote:Wow! Thanks for responses. At the risk of exposing my ignorance... I'm glad I posted this question. The lathe work is something I've always wanted to try, and I'm finding it interesting and fun- and gaining more and more respect for the people that do it well.

These wheels are part of a 2x72 belt grinder build, and since I've seen 1616zz bearings in use on other machines it seemed reasonable to use them. The bearings accommodate a 1/2" axle so I plan to use a 1/2" bolt; I drilled a 9/16" hole through the wheel so contact would only occur between the bearing and the bolt. The "well" for the bearing will center around the axle hole, and I thought I would leave a raised ridge around the axle hole so that surface of the wheel would contact only the inner ring of the bearing. Is that a good idea, or is it better to use a spacer on the bolt?
I don't understand the 9/16" hole part on the wheel. Do you have any pics? I would have left it at 1/2" and put the bolt through the bearing ID.
grinder wheels.jpg
grinder wheels.jpg (18 KiB) Viewed 721 times
Artie F. Emm
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electrode wrote: I don't understand the 9/16" hole part on the wheel. Do you have any pics? I would have left it at 1/2" and put the bolt through the bearing ID.
My thinking for the 9/16" hole was to avoid contact friction between the axle and the wheel. That way the axle will only touch the bearing ID. To me that makes intuitive sense, but please let me know if that's wrong, or a recipe for failure. I've only drilled one wheel so far, happy to pivot and make the others right.
Dave
aka "RTFM"
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Id of the bearing is 1/2, so slightly larger bore through the rest of the wheel for axle clearance. You're putting a bearing on each side yeah like on a skateboard wheel? Some of the ones I've seen just had a single bearing but it seems like a good way to chew it out.

Can't really tighten them up either, well the drive wheel and one of the wheels you can but the others will have to have a bit of play so they can find their center on the belt?
Nowadays people know the price of everything and the value of nothing... Oscar Wilde
Artie F. Emm
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You got it, a bearing on each side of the wheels, much like a skateboard wheel.

In the picture that Electrode added, the largest wheel is the drive wheel, mounted on the motor shaft. The mid-size wheel is a tracking/idler wheel, which has a side-to-side tracking adjustment and is mounted on a spring arm to take up slack in the belt. In the aluminum version of these wheels, the drive and idler wheels are domed with a peak in the center of the tracking surface that keeps the belt running true. The two smallest wheels are guide wheels and are flat, not peaked. Overall tracking also requires the wheels to be mounted on the same plane.
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Dave
aka "RTFM"
electrode
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Rupes wrote:Id of the bearing is 1/2, so slightly larger bore through the rest of the wheel for axle clearance. You're putting a bearing on each side yeah like on a skateboard wheel? Some of the ones I've seen just had a single bearing but it seems like a good way to chew it out.

Can't really tighten them up either, well the drive wheel and one of the wheels you can but the others will have to have a bit of play so they can find their center on the belt?
I think I understand now. Do the wheels come with a hole in the center that is 1/2" and you need to machine the wheel for the bearings to press into? Then the center is drilled slightly larger for clearance like you said to keep the axle (bolt) from rubbing on it? Makes sense to me. I would have thought if you bought the wheels they would have the bearings already in them. But I looked back at the first post and realized you are making the wheels. Carry on...sounds good to me. ;) As long as the ID of the bearing is pressed against the inner part of the wheel you will be fine.
Erich
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I would make some spacers to fit between the two bearings.
Use 5/8 od 1/16 wall tubing. Open the id so the bolt fits thru.
Press the bearings in with the spacer between the inner rings.
Now you can install the 1/2 inch bolt and tighten the daylights out of it and it won't put any undue stress on the bearings.
Another spacer on the outside will set the location of the wheel relative to the main structural plate.
electrode
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Erich wrote:I would make some spacers to fit between the two bearings.
Use 5/8 od 1/16 wall tubing. Open the id so the bolt fits thru.
Press the bearings in with the spacer between the inner rings.
Now you can install the 1/2 inch bolt and tighten the daylights out of it and it won't put any undue stress on the bearings.
Another spacer on the outside will set the location of the wheel relative to the main structural plate.
I was starting to post that same thing in my last remarks but if he does it correctly the inner race could be on solid meat just like a spacer would be. I was thinking on the lines of a motorcycle wheel how there is a spacer tube between the bearings for the same reason. :D
Artie F. Emm
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The width of the bearing is 3/8. My plan is to cut the bearing opening to that 3/8 depth in a ring that will touch only the inner bearing ring, and cut the rest of the opening a touch deeper. That should provide that same compressibility of the tube idea.
Dave
aka "RTFM"
electrode
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Artie F. Emm wrote:The width of the bearing is 3/8. My plan is to cut the bearing opening to that 3/8 depth in a ring that will touch only the inner bearing ring, and cut the rest of the opening a touch deeper. That should provide that same compressibility of the tube idea.
You got it. ;) The tube on a motorcycle wheel for example is precisely machined to allow the axle nut to be torqued while keeping the bearing from any unwanted lateral force which would greatly shorten the life of the bearing. But you got that figured out so go for it.
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Used to tick me off as a kid with roller skates, when you hold the center of the bearing the outer spins just fine. When you install and have two bearings on that axle because they didnt have spacers in between when tightened it up it would put lateral force on the bearing and bind it up and so you'd have to back off the nut. Always seemed a dumb design to me. It basically means the bearings inner race can rotate on the axle. I'm pretty sure they're still like that. I think its just the weight of the rider that forces the axle down on the inner race and the bearing takes the line of least resistance and works normally rather than spinning on the axle.

As for the grinder, what would be its primary use? I had something very similar in mind but with a removable front end that could be swapped out for an attachment like this. Having the entire unit mounted to a 6 or 8 inch square post concreted in the ground would be great especially if you wanted to hinge it so it could be rotated to a horizontal plane. I was thinking along the lines of knife making and general purpose

http://www.ebay.com.au/itm/231429758787 ... EBIDX%3AIT
Nowadays people know the price of everything and the value of nothing... Oscar Wilde
Artie F. Emm
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I'm thinking of general fabrication use. For knife makers a machine like this is a must have, but i'm not a knife maker... yet, at least. Swapping ends out and using rollers like the ones in your link, rotating 90* for grinding on a long edge- it's a very versatile machine. This link shows the machine in use and swapping ends out, and shows it quickly and easily fishmouthing pipes for welding, which is an eye opener!

https://m.youtube.com/watch?v=BYllaxuzMk0
Dave
aka "RTFM"
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