binding barrel bolt meets a carriage bolt

good day -

first off! i am not a machinist - so you will have to be a bt forgiving. :)

i have a dilemma - i am working on this design - and the intent is that the (green) cylinder is to freely roll when applied to a surface (like a pizza cutter.)

however - the binding barrel (blue) i sourced out at mcmaster-carr - i do not want to rotate. and i certainly don’t want to too tight as it will start to bend the channel.

it’s also critical that the ends have no drive - but a nice polished-finished look.

maybe an adhesive?

i came across google images - where i can see a binding barrel with a hex at the base (like a carriage bolt) i think this would work - right?

but i imagine it’s easy to drill the hole in the channel - but the hex shape not so?

so i am at a loss.

if you look at the reference in the yellow circle - the bolt is normally welded and then sanded off. i don´t like this look. (unless there’s a machine shop that could perform this with a better finish?)

what are my options in achieving this function?

best regards -

jón

Bearings in the cylinder?

interesting - but how do you keep the cylinder in place?

How I did it for the rollers in my 2" x 72" belt grinder...

1. A bore in the cylinder as wide as the inner diameter of the bearing outer race, with counterbores in the ends a light press fit with the outer diameter of the bearing outer race - just a step in the ends of the bore that accommodates the bearings.

2. A thrust sleeve between the bearings, about the same size as the inner race.

3. A washer the size of the inner race between the bearing and the channel wall to space it off.

When the bolt's tightened up it can pinch the channel wall, washer, bearing inner race, thrust tube, 2nd bearing inner race, 2nd washer and 2nd channel wall tight and solid, leaving the bearing outers and their press fit into the cylinder to spin but not go anywhere else.

Thrust tube is super important with "normal" ball bearing sets otherwise the axial compression through the washers will flog the races out in no time. Trust me on this. Conical bearings would also solve this but they are super sensitive to how tightly you do up (and keep) the axle bolt.

Quote:

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Originally Posted by dharmic

How I did it for the rollers in my 2" x 72" belt grinder...

1. A bore in the cylinder as wide as the inner diameter of the bearing outer race, with counterbores in the ends a light press fit with the outer diameter of the bearing outer race - just a step in the ends of the bore that accommodates the bearings.

2. A thrust sleeve between the bearings, about the same size as the inner race.

3. A washer the size of the inner race between the bearing and the channel wall to space it off.

When the bolt's tightened up it can pinch the channel wall, washer, bearing inner race, thrust tube, 2nd bearing inner race, 2nd washer and 2nd channel wall tight and solid, leaving the bearing outers and their press fit into the cylinder to spin but not go anywhere else.

Thrust tube is super important with "normal" ball bearing sets otherwise the axial compression through the washers will flog the races out in no time. Trust me on this. Conical bearings would also solve this but they are super sensitive to how tightly you do up (and keep) the axle bolt.

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thanks for explaining this - makes total sense. now i just need to go back to the design and find these parts! :)