RFQ - Aluminum Expansion Roller Cores

See attached print. Please provide price and lead time. I have STEP files and PDF of drawing if you're interested as well.

Thanks,

Evan

[email protected]

Nothing? I thought people would be all over this one. Open to suggestions if the tolerances are un-reasonable.

Do you have a local wire edm source?

Broach them with a 6mm broach while still in the lathe. My 2 axis mazak can index 180 degrees no prob, but don't know about the broach length requirement. 6 parts likely not worth a special broach.

I think member Finegrain does broaching, maybe he hasn't seen this yet.

Dualkit said:

I think member Finegrain does broaching, maybe he hasn't seen this yet.

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Howdy,

Yes, I saw it, but not knowing how accurately the 2 slots need to be timed is a deterrent. Custom broach bushing can get within a few thousandths, but what a PITA for 6 pieces.

Regards.

Mike

So the keyways are the difficult component here? There are two keyways for the sake of balancing the core. Only one is used. This piece goes on a custom mandrel which goes on a handheld grinder, so we're not talking precision equipment here. However, the relatively tight tolerances for the application are preferred since this is used for polishing stainless, so vibration in the roller turns into chatter marks in the work piece, which just creates more work in the buffing stages.

It does bring up an interesting point though, because the rubber shop told me the part should be symmetric for the sake of balancing, but won't the roller be unbalanced once installed since there's a key on one side, but not on the other? I would think the ideal way to balance it would be one keyway, then install the roller on the mandrel and balance the entire assembly. But I could be wrong... Especially since the manufacturer of these uses 4 keyways spaced 90 degrees apart.

There's a lot of reasons why I want to make my own instead of buying the pre-made ones. For one, I don't like the rubber that's on the stock ones. Looking for something a little more custom. And two, the stock ones have a plastic core that wears out and can't be stripped and recovered.

Any insight on design is appreciated as well.

A steel key will be heavier than the aluminum. Cutting a key way opposite that is not used will make the imbalance worst not better unless you fill the slot with a 1/2 key to balance the weight. Not sure how you keep it in place though, locktight might work.

CarlBoyd

I always have to giggle when it is a metric key in a imperial hole. Balancing after the fact is the only way to get it dead nuts, but how many rpm do you plan on putting through this. If you are planning to apply a coating to them, your balancing after that action would be best as your never going to get that perfectly true. Saw lots of post machining of rollers after coating. stringy rubber bits everywhere.

Well could someone make these pretty easily if there were only one keyway? Or still a PITA?

Econdron, I will bite. Email me at [email protected]. I am located in Arkansas.

when do you need them by?

Machinist_max said:

when do you need them by?

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No rush. Just replacement parts.