Re: Re: Servo Motor Shaft Modification

> First off, John you are a true craftsman.
> Second,
> I don't agree with you about the 3/8" shaft "hardly being strong
> enough". NEMA 34 steppers have a 3/8" shaft and are made in
> multiple stacks up to 2000 oz-in. Maybe they use a stronger
> alloy for their shaft but they transfer a tremendous amount
> of power through a 3/8" shaft. I don't know how much torque it
> would take to twist a 3/8" shaft, but I'll bet it is more than
> you are putting into the bridgeport. Someone correct me if I
> am wrong.
>
> Scott

Scott, possibly it would but I have taken a motor off the Bridgy that
carries a H series timing belt and it's on 16mm bore.
I can't swop the pulley on the Z axis spindle without a lot of bother as it's the integral one.
Perhaps I go for overkill in mechical design but it seemed easier to me to use the existing
pulley, belt and the rest and just mod the motor shaft to 16mm to match the pulley than
to mod the motors shaft and pulley and loose rigidity in the meanwhile.
If at a later date I can get some of the rare 90 volt servo's that some Beavers had fitted then
these will just bolt on in place of the treadmill motors.

One other point is I need the total length of 2" to clear existing casting and line up.
Those type 34's on 3/8" do not use long slender shafts and limit them to about 1".
I hate shaft extenders as they work the same way under side load as a milling cutter
does in a drill chuck, they walk off, had to repair and replace many.



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