Broaching Ends of Cylinders

[Sperkowsky]

Our team is looking at putting a cylinder on the end of a chain driven piece of 1/2 hex stock. That way we could position it at any angle.

What would be the easiest way to accomplish fixing a cylinder to a hex shaft. We have come up with 2 ideas.

1. Broach the bottom mounting hole.
2. Drill out the end mounting hole and weld in Competition robot parts roller end cap.

We do not have access to a welder or an arbor press/broach so neither of these are too easy. Welding is slightly easier as there is an auto repair shop across the street that can do it but they will most likely charge for it.

Are there any good strong cots solutions for this considering the cylinder is 36" long?

Thanks.

[Mike Marandola]

You should reread the pnuematic rules because both broaching and welding the cylinder mounting hole is illegal.

[EricH]

We'll start by ruling out both 1 and 2 by R76--neither would be an allowed exception as nearly as I can tell. Pay close attention to R76C as it may give some ideas--like you might be able to build an end cap that would thread onto the cylinder's mount fitting, with a hole that allows a bolt to attach to the hex.

[Sperkowsky]

Originally Posted by EricH

We'll start by ruling out both 1 and 2 by R76--neither would be an allowed exception as nearly as I can tell. Pay close attention to R76C as it may give some ideas--like you might be able to build an end cap that would thread onto the cylinder's mount fitting, with a hole that allows a bolt to attach to the hex.

Would that be something we could make with our limited resources? We have a water jet sponsor so could be getting get one cut and then thread the outside with a simple tap and die set?

[EricH]

Originally Posted by Sperkowsky

Would that be something we could make with our limited resources? We have a water jet sponsor so could be getting get one cut and then thread the outside with a simple tap and die set?

Sort of. Actually, I think you could do it without a tap. Give me a couple of minutes and I'll see what kind of sketch I can come up with.

You'll have to put the dimensions on the attached item, but what I'm seeing is a custom clevis. The top (round hole) is sized in distance to lock the clevis to the cylinder's base. The hex is far enough back to allow the other side of the clevis to butt up against the base of the cylinder's mounting while maintaining strength.

This would be a two-operation setup on a waterjet that could handle thick material. Or with a machining sponsor.


The threading option would replace the upper hole, and require rather more drilling out of holes.

[Sperkowsky]

Originally Posted by EricH

Sort of. Actually, I think you could do it without a tap. Give me a couple of minutes and I'll see what kind of sketch I can come up with.

You'll have to put the dimensions on the attached item, but what I'm seeing is a custom clevis. The top (round hole) is sized in distance to lock the clevis to the cylinder's base. The hex is far enough back to allow the other side of the clevis to butt up against the base of the cylinder's mounting while maintaining strength.

This would be a two-operation setup on a waterjet that could handle thick material. Or with a machining sponsor.


The threading option would replace the upper hole, and require rather more drilling out of holes.

Thanks so much!

[Kevin Thorp]

Bimba and most other cylinder manufacturers offer hex mounting nuts. You could weld an adapter onto the nut then screw it onto the cylinder. Or use a taller nut with the same thread diameter/pitch.