You could probably have the handle line bored, or have the shaft lathed down at a local machine shop. My smaller hand wheels have a smaller hole than the shaft diameter. They have a shaft that necks down in diameter. My larger wheel (10" I think) uses the full size of the shaft. My motor operator also uses the same size shaft as the Powerstats.
________________________________
From: David Rieben <drieben@xxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Thursday, July 3, 2014 10:09 AM
Subject: [TCML] Bigger Variac Control Wheel
Hi all,
I have been recently trying to secure an economical control wheel to replace the factory black phenolic control knob wheel on my 4-stacked 1256D
Powerstats in my Green Monster pig coil control panel. Reason being is that the turning of the combined 4 variacs while smooth, does offer significant resistance to overcome the friction of turning the rotating guts of 4 large units. I'm sure the factory 7" outer diamter control wheels that Powerstats come with are more designed for operating a single variac unit and not multiple units. (Multiple units are typically operated with a remote control motorized drive). I can run the variac thru its range simply enough, but to do so comfortably pretty much requires both hands. So, I'm kind of looking for something a bit larger, say in the 10" to 13" diameter range, or maybe just 8" diameter if it had one of those "suicide knob" type handles on the wheel, like a lathe control wheel, for example. I've spotted a few possible candidates on eBay but am a little concerned on how well the hub would match up with my 3/4" solid steel shaft through my variacs. Some of
the boat steering wheels have the tapered 5/8" to 3/4" hub hole and that would not work for a solid 3/4" shaft. Some of the large valve control wheels look like a possible fit or if the hub was too small but straight and untapered, I could simply bore it out to the required 3/4", although finding a 3/4" standard twist drill bit in my local Home Depot has proven to be rather illusive. Anyway, I do prefer the manual hand control to motorized control but would like the find a control wheel that offers a bit more leverage. Here a couple of eBay candidates that I have found:
http://www.ebay.com/itm/301222411547?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT ; and
http://www.ebay.com/itm/121374903703?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT ;
Any suggestions from those more mechanically inclined than me (not difficult at all :-) would be most welcome.
Oh yea, is anyone else having trouble snipping a chosen part of a post when responding via "reply all" through the new format of this list?
Thanks,
David
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