Re: [TCML] SRSG curiosity

["Quarkster" <quarkster@xxxxxxx>]

Andrew -

Possibly faulty logic.

(Additionally, electrical techniques for adjustment of rotor angular 
position have superseded "mechanical" adjustment.)

First, good mechanical design would dictate that the RSG rotor assembly be 
mechanically "keyed" to the motor shaft via a keyway, splines, a flat on the 
motor shaft, etc. A "quick and dirty" connection that would allow angular 
adjustments (like setscrews, etc.) is just not reliable under the 
acceleration/deceleration and vibration loads that a RSG will typically see.

Second, it would be difficult to make small, repeatable, incremental 
adjustments in angular position between the motor shaft and the rotor 
assembly without some way to lock the motor shaft against rotation while the 
adjustment is being made.

Third, accurately marking the relative positions of shaft and hub would be 
difficult. Reference marks closely scribed on the relatively small diameter 
motor shaft would represent a large change in angle out at the radius of the 
RSG flying electrodes.

Fourth, adjusting rotor position on the motor shaft would be purely a 
"trial-and-error" process requiring that the system be shut down, the tank 
capacitor discharged, etc. and obviously would not allow making any 
adjustments while the system is operating, which would allow real-time 
optimization of coil performance under operating conditions.

In the end, making a "cradle assembly" that allows the motor housing to be 
rotated is usually much simpler, much easier to adjust, and much more 
practical than trying to adjust the angular position of the rotor on the 
motor shaft.

However, even more elegant than a mechanical phase adjustment is an 
electronic one, using an adjustable inductor (typically a small variac) and 
a suitable capacitance value to adjust the motor's phase angle, and 
therefore the angular position of the rotor, relative to the sinewave of the 
AC powering the motor. Properly set up, this simple circuit will allow up to 
90 degrees of angular adjustment (with a 3600 RPM motor) while the TC is 
operating.

See John Freau's description of the electrical phase adjuster at:
http://futuret.110mb.com/

Also see Gary Lau's complete SRSG assembly with phase adjuster at:
http://www.laushaus.com/tesla/sync_gap.htm

So, probably no sheep involved at all .....

Regards,
Herr Zapp
----- Original Message ----- 
From: "Andrew Robinson" <teslamad@xxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Friday, November 06, 2009 9:56 AM
Subject: [TCML] SRSG curiosity


So why does everyone devise a way to rotate their SRSG motor in its mount 
rather than rotate the disc coupling on the motors shaft. Seems like a lot 
more work to rotate the motor than to rotate the disc... Is this just 
because someone did it first and everyone else followed like sheep, or is 
something wrong with my logic?
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