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Re: SRSG - rotor attachment

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

Gerry -

No, the "quick disconnect" split bushing (by itself) will not work either. It has exactly the same problem as the split Browning bushings described by David Reiben: it is only one half of the "pair" of parts needed to compress the split bushing and cause it to grip the motor shaft.

Look carefully at the QD bushings and you'll see that the bushing itself has no means of compressing the slit in the bushing so the bore diameter is reduced and the bushing can grip the motor shaft. Look closely at the QD bushing drawing, the outer diameter of the body is tapered, and must be forced into a mating female taper on a separate part so the split bushing will be compressed, reducing the bore diameter and gripping the motor shaft. The "missing mating part" has three tapped holes that align with the three holes in the flange of the split bushing. When three bolts are installed through the holes in the flange of the split bushing into the tapped holes of the "missing part" and tightened, the split bushing is pulled into the "missing part". Since the tapered bore of the "missing part" is not split, it cannot be forced open, but the split bushing (because of the split) can be forced closed, reducing the diameter of the inner bore and gripping the motor shaft. It seems like this "pair of mating tapers" is difficult for some people to visualize, so Monday I'll throw together a simple CAD drawing showing a cross section of an assembled coupling and Terry may be kind enoughy to post it at Hot-Streamer.

As clearly noted in the McMaster description of these bushings, they are for use with Quick Disconnect bushing-bore sprockets and pulleys (page 963 on M-C's current on-line catalog). These sprockets and pulleys contain the female taper needed by the "missing part". The problem is that the sprockets are fully hardened, and to make a clean-looking and functional "hub" that you could mount an RSG disk to you'd want to remove the sprocket teeth, and add 4 to 6 mounting holes for the disk. The only way to do this would be by precision grinding and/or EDM (electro-discharge) machining, usually not processes available to the hobbyist.


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Saturday, May 13, 2006 9:39 PM
Subject: Re: SRSG - rotor attachment

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Scott,

It appears the quick disconnect (QD) bushing is made to order. It is an interface to bore sprocket and pulley but just the bushing is what one needs, I think.

Try www.mcmaster.com and search on "split taper bushing". At the top of the page you'll see the quick disconnect bushing. Click on "additional information" and look at style SF. Its flange OD is 4 5/8 and can be ordered for bore sizes 1/2 to 2 1/4 with the standard keyway.

Gerry R.

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

David -

The split-taper bushings listed by McMaster-Carr are just the adapters needed to couple a motor shaft of a specific diameter to a flanged hub that you would bolt the RSG rotor to. As far as I can tell, McMaster does not offer just a flanged hub with the correct female taper to accept the split-taper bushings.

They do offer hardened steel sprockets that accept the taper-lock bushings, but these are through-hardened and would take a lot of machine work (EDM & grinding) to remove the sprocket teeth and add the bolt holes for the RSG disk.

Or have you found something hidden in the McMaster catalog that would provide the complete solution for mounting an RSG disk directly to a motor shaft (3/8", 1/2", 5/8", or 3/4" dia)?

Scott Hanson
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx
Sent: Saturday, May 13, 2006 9:56 AM
Subject: Re: SRSG - rotor attachment

Original poster: DRIEBEN@xxxxxxxxxxxxxxx

You can get these adapters from McMaster-Carr
or a local branch of an industrial supply
chain like Johnstone or Grainger. What you're
looking for is called a "split taper bushing".

David Rieben

----- Original Message -----
From: Tesla list <tesla@xxxxxxxxxx>
Date: Saturday, May 13, 2006 8:30 am
Subject: SRSG - rotor attachment
To: tesla@xxxxxxxxxx

> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
> Hi All,
> My previous SRSG used a motor that already had an aluminum piece
> to
> attach the rotor to the motor shaft.  My higher HP motor does not
> have this adapter (not sure what the correct name for it is).
> Does
> anyone know where I can get an adapter for a 5/8 dia motor shaft
> to
> attach the rotor to (or do I need to machine it)???
> Gerry R.