Re: Cirkut calibration

[Ron Klein <panorama@xxxxxxx>]

Get ready for a round of true frustration.

Actually it isn't too hard to adjust the governor on a #10 cirkut.  First
you should totally disassemble and clean the entire camera, but if you are
in a hurry, this is what I would do:

Run down the motor and check the end play in the governor.  This is adjusted
by loosening the nut on top of the governor and screwing in or out the screw
on top.  Don't tighten it too much.  The original factory setting was quite
loose (noticeable end play).  Toward the top of the ball springs you will
notice a small collar with two set screws.  This allows the ball spring
assembly to move up and down.  First, set the speed selector to the slowest
speed (one half second).  Then slightly loosen the set screws on the collar
and move it up or down to achieve the right speed for one half second.  This
is trial and error with a lot of tries.  It is a good idea to adjust the
speed selector up and down after making an adjustment and start and stop the
motor a couple of times before timing the speed.

Determining the speed is easily done by timing say three revolutions to get
a good one drum revolution speed. Then use this simple formula for
calculating the speed:

        drum circumference             slit width
        -------------------             =       -------------
        time one revolution               effective shutter speed

The drum diameter of a #10 camera is usually 3 5/8 inches or 11.39 inches.
The slit width is usually 1/4 inch or .25 inches.

In other words,  (time of one drum revolution) times .25 divided by 11.39 =
effective shutter speed.

The real frustration comes after getting the 1/2 second speed adjusted
properly.  It is then that you notice that the other speeds are not correct.
The problem is not easily fixable.  The ball springs have lost the original
tension and allow the balls to spin at a different speed.  This can be fixed
by making new springs, but only with great difficulty.  For myself, I need a
good slow 1/2 second, and anything after that is negotiable.  If you know
that 1/10 is actually 1/15 is that so bad?  And you might get lucky and have
a camera that will actually adjust to ALL speeds correctly.  Most cameras
are within 20% of the right time, and you should be able to hone that to 10%
if you're fussy.

I cannot over emphisize that in order for a #10 camera to run right, it must
be thoughly cleaned and oiled or you don't have a chance of keeping the
previous adjustments.

good luck

Ron Klein






----- Original Message -----
From: Scott Davis <sddavis@xxxxxxxx>
To: <panorama-l@xxxxxxxxxxxxxxxxx>
Sent: Monday, August 02, 1999 4:37 AM
Subject: Cirkut calibration


> Does anyone know how to adjust the governor in a Cirkut to the correct
> speed?  I would like to get it to agree with the speed setting on the
> magazine.  We're talking about a #10 camera with key wound system.
>
>