# Cutting Flywheel Rings



## Ken I (Apr 2, 2012)

This goes under the heading of "mad idea that works"

I needed a couple of rings for the flywheel on my elbow engine - I had a bronze disk - which machined would become mostly chips so I decided to "butcher" it into a series of rings using my plumbers hole saw kit.






The largest saw is 90mm diameter and the whole thing did not take too long.

Whether its worth the effort or not is moot.

Do all the rings from one side about half way through - with the pilot going all the way through. Turnover and starting with the largest, work inwards & go all the way to breakthrough.

Some sort of clamping is mandatory.

Use decent bi-metal hole saws - not those cheap and nasties that can barely cut wood.

Ken


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## Holt (Apr 2, 2012)

Nice idea! and now you have to make at least 3 different size machines ;D

Holt


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## krv3000 (Apr 2, 2012)

HI a good tip


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## Captain Jerry (Apr 2, 2012)

Ken

I used a 3.5" hole saw on aluminum not long ago, I can't remember why, but I do remember that it was almost too much for my little X2 mill. Even with plenty of lubrication (WD40) and frequent clearing of the kerf and picking chips out of the gullets, the overload kept stopping the motor. A really good hole saw, as you point out, would help. Mine wasn't. 

And the material certainly makes a difference. I don't think I will do it again with aluminum. Its not worth the risk of motor damage. But to get maximum use of a chunk of bronze I think I might. 

On the other hand, the cost of a new, good quality hole saw is nearly as much as the cost of the bronze.

Jerry


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## Ken I (Apr 2, 2012)

Captain, I thought the same thing myself - however I do have a fairly powerful column drill and a rather underpowered lathe - so all in all it saved me time as well.

As to the hole saws - I already have those.

I'd rather have a couple of gash bronze rings lying around than a pile of chips.

I'm finally girding up my loins to complete the elbow engine but I have been loath to tear it down to make all the neccessay refinements and adjustments.

I don't know why but once I get an engine going, terminal ennui sets it and it can be months before my annoyance with its quirks and unfinished status overwhelms my reluctance (or could it just be laziness) to do the finishing off.

Completed project should follow within a month complete with a full set of drawings & documentation for the downloads section.

Regards,
      Ken


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## arc_eyes (Apr 2, 2012)

Excellent idea.
I hate wasting anything.


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## Foozer (Apr 2, 2012)

That drove me batty trying to use hole saw(s) to cut a ring out of stock. Either burned up the saw(s) or drill press would stall.
Finally chain drilled it out. 
Marv IIRC has a program to help regarding chain drilling

Have no idea what the "looked like Brass" stock was. Gave a sorta burnt golden color to the chips when turned.

Moral is, "If at first you don't succeed, get a Bigger Hammer"

Robert


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