Re: Balancing Rotary Disk???

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "davep by way of Terry Fritz <twftesla-at-uswest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:
> 
> Original poster: "Oxandale, Terry by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <Toxandale-at-SPP-dot-org>
> 
> I know that trial and error balancing is a PITA, but I still found it
> the only "dynamic" way to balance my disc (13") without leaving my
> garage. I drilled (1/4") a ring of evenly spaced holes (16 total but the
> more the better) around the disc on a concentric circle inside of the
> circle of contacts. Then using two steel bolts and nuts, I attached
> these bolts to the disc in any two of these holes exactly 180 degrees
> apart. This way they still did not effect the original balancing of the
> disc because they were on opposite sides. Then as I moved the bolts
> closer together (with each on/off cycle of the motor up to full speed),
> I could find a point at which the disc/motor assemble would not vibrate
> any more. Obviously the starting point may need to be changed if the
> original starting points are not correct, but this way the amount of
> counter-mass the disc sees being placed on it varies because you are
> using two bolts at a balanced point to begin with. I have found that I
> can achieve a good 3000 rpm balance within an hours worth of time.
 
> (Un) Terry

	An interesting approach, and one that follows, i believe,
	an important element of high performance balancing.  While it
	is possible to get a balance with one weight opposite the
	heavy spot, a 'better' one is obtained with two, smaller,
	weights 'spread' form directly opposite. Un-Terry's technique
	accomplishes this....  Other techniques to do this 'split'
	balancing should yield advantageous results..

	best
	dwp