Re: 3 Gange PowerStat 146U-3 Variac Problem :-(

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Mike" <induction@xxxxxxxxxxx>

Hi Terry,
                 You could be dealing with a heat shrink fit there.
The also often to this on motor sleeves, all sorts of things.
Think in terms of expanding when hot by a few thousandths and when it
cools, presto, nice tight fit.
I  have tech supported a guy that had a generator mounted on his truck
along with a 10 kW solid state induction heater. His thing was dig a trench
with a machine for laying down pipe. At his shop in the morning, he would
take one end of 20 feet pipe sections, heat them with the induction machine,
slip in a sleeve a certain distance, as the pipe cooled quickly, it held 
the sleeve.
When he got to the job site, he had a whole bunch of pipes with a sleeve in
one end. With a welding cable feed and a 50 KC heater, he then heated the
pipe end with no sleeve,m slipped it into the next pipe end with a sleeve and
built a pipe line. Takes maybe 30 seconds per joint. Fit is so tight when
cooled that it is steam, water and gas tight. Works great.
I think maybe that is not pressed, it may just be heat shrunk.
Get over 700 degrees F, target should expand a few 1000ths, pull
and go.
Mike

----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Cc: "david baehr" <dfb25@xxxxxxxxxxx>
Sent: Saturday, April 23, 2005 9:05 PM
Subject: 3 Gange PowerStat 146U-3 Variac Problem :-(


> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi All,
>
> I have a big 3 section Powerstat  146U-3 that has never been used.  It is 
> 0-280VAC at 30Amps per section.
>
> It would be nice to break it down into three separate variacs.  However, 
> the shafts have what seems to be a pressed on insulator (red circle):
>
> http://hot-streamer.com/temp/PowerStat-146U-01.JPG
>
> http://hot-streamer.com/temp/PowerStat-146U-02.JPG
>
> I cannot take it apart as needed with these pressed on parts :-(((
>
> There is not enough shaft between the sections to think about sawing it.
>
> I just wanted to check for any obvious solutions you all might know. 
> Otherwise, off to E-bay man (as a full unit) it will go...
>
> I also have a 240VAC 15A 3 section Powerstat unit that looks like it has 
> the same dumb problem  :-p
>
> Cheers,
>
> Terry