Re: stacking variacs

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

Original poster: Yurtle Turtle <yurtle_t-at-yahoo-dot-com> 

Could be a slight misalignment of the holes in the
frames. You might try rotating the frames so the
"fronts" no longer line up. I assume yours have four
threaded rods, so that's four possibilities. You can
tighten the wiper to the shaft at any position, so
that shouldn't be a problem.

Another possibility is that the frames are being
compressed. Maybe use eight nuts per rod. Then you can
tweak each nut, and forget about using spacers. It's
possible that the wiper on one or both isn't parallel
to the threaded rods. You may have to put one
powerstat deliberately out of whack, in order to get
the wipers to perfectly line up.

Worst case you can drill the holes oversized, to allow
lateral adjustment. It may also be that the wipers
just don't line up.


Good luck
Adam

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: DRIEBEN-at-midsouth.rr-dot-com
 >
 > Hi all,
 >
 > I recently obtained another 1156 style variac to
 > series with my
 > 5000 watt rated Luxtrol. They have identical
 > 1156/1256 type Power-
 > stat frames so they match right up for placement of
 > a common shaft.
 > The problem that I'm having is when I try to tighten
 > the nuts on
 > the ends of the all-thread rods that are holding
 > them together, the
 > shaft starts getting in a bind to the point that I
 > can hardly turn
 > the control wheel/knob. I've ran across this problem
 > in the past
 > but it seemed that I was usually able to overcome
 > the binding by
 > being sure to tighten all 8 of the nuts as equally
 > as possible.
 > This dosen't seem to work this time though and I've
 > had to just
 > leave the nuts only finger tight to be able to
 > operate the control
 > knob. I am using (4) spacers of 2" long pieces of
 > steel tube placed
 > over the all-thread between each variac and since I
 > had to cut them
 > out, maybe they aren't precisely the same length.
 > Maybe that's
 > what's causing the binding? Any ideas?
 >
 > David Rieben
 >
 >



	
		
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