The "High Speed
Only" Vintage Mixmaster (Models 10, 11, and 12)
(Best Mixmasters Sunbeam ever built!)
to locate you mixer's model number
I get this question a lot so I hope this article will
help. Your Mixmaster will run, but no matter where the dial's set, it
only runs at full speed with little or no adjustment possible.
First, make sure the governor's tiny
adjustable-length speed adjust pin hasn't fallen out. They love to pop
out and hide on the floor when the knob's removed. The pin's location is
noted in photo 1 below. If it's gotten lost, let me know. I still have a
quantity of good/used ones on hand.
If the pin's in place, the most common cause of this,
by far, is a shorted governor capacitor. That's located on the bottom of
the governor, where there's one of my new ones mounted in photo 1 below.
Old capacitors (usually cardboard-cased) fail without warning, often
violently, so I always recommend replacing an original one whenever you
have your mixer apart, as preventive maintenance.
To quickly check for a shorted cap without a meter,
pry the old one out (the left contact arm is flexible, designed to
spring open), put the knob back on (remember that little pin!) and run
it briefly. If there's some speed control with the cap removed, you
immediately know the cap is shorted and should be replaced.
Just don't run it very long that way, as you risk
burning the governor contacts. One of the functions of that capacitor is
to protect the contacts from arc-damage.
If you need one, I try to always keep a good quantity
of these capacitors fabricated and on hand (brand new), posted
The next mostly likely cause of "high-only" is under
the governor. The tiny (1/16" diameter) steel pin that pushes on the
governor contact arm can wear right back through its tiny nylon socket,
causing loss of speed regulation.
It's hard to see without pulling the governor out, but looking under the
contacts carefully with a strong light will reveal the tip of the pin
poking back through the socket if this is the issue.
Back in the day, we could order that little socket
and its felt oil wick from Sunbeam, but these days you have to replace
the governor assembly with a good/used one (not as hard as it sounds). I
still (as of Spring 2021) have just a few good/used ones left in stock.
Part # 10-1057GU, I don't have enough of them to justify listing them
here on the website (they're no longer available new, either).
If the push-pin socket's OK, the next most likely cause is a problem
with the centrifugal leaf on the rear of the armature. This is a thin
steel ribbon that straightens as speed increases, pushing the steel
push-rod backwards. Picture the old rotating centrifugal ball governor
on a steam engine; same principle.
It's rare, but that steel leaf sometimes breaks,
again causing high speed only, and requiring armature replacement. I
still have a few reconditioned armatures on hand if needed.
Hopefully the "high-only" issue with your mixer is
one of those listed above; it almost always is. If you should have any
questions on this, feel free to
drop me an email
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Many Thanks! - Dave