Re: Small Rotary

To: tesla-at-pupman-dot-com
Subject: Re: Small Rotary
From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
Date: Tue, 22 Oct 1996 22:04:38 -0500
>>From SSNSanders-at-aol-dot-comMon Oct 21 21:39:03 1996
>Date: Mon, 21 Oct 1996 10:10:15 -0400
>From: SSNSanders-at-aol-dot-com
>To: Tesla-at-pupman-dot-com
>Subject: Small Rotary

>Ive had an Idea:0   What about a hard drive disk for a rotary gap, maybe one
>of the old 20 meg large diameter disks. The bearings in theese things are as
>smooth as silk, they are balanced well. If it could be taken out and a motor
>,say 1800RPM incorporated in the system, attach electrodes and balance, maybe
>even belt drive it and run it in a horizontal position with 2 electrodes
>stationary on either side making with the disk electrodes? What do you think?
>anybody, If its feasible Im going to start on it. The comp. store has a bunch
>of old large 20 meg drives for very old computers for about 20.00 each.
>  Stephen Sanders

Stephen,

I think you have discovered a well guarded secret!  I have a pair of 
old hard drives I picked up from a surplus source with the intent of 
using them for a future rotary project where higher precision will be 
required.  These disk pack drives are beautifully machined, on jewel 
like bearings as you say.  Mine have a toothed timing belt to connect 
the spindle to a approx 1/2 HP motor.  Memory tells me these things 
ran at 3600 RPM.  There is a nice flat stainless steel platter about 
5-6 inches diameter with threaded machined holes around the 
circumference which can be used to bolt your fiberglass or whatever 
wheel up against and have hiogher expectations of it running true 
without lateral wobble.  I would certainly recommend these dinosaurs 
of computer technology as a great starting source of hardware for a 
rotary gap project!  Your price of $20 is excellent value.

rwstephens