Archived posting to the Leica Users Group, 2003/01/22

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Re: [Leica] M motor drive/winder/RabidWinder
From: John Collier <jbcollier@shaw.ca>
Date: Wed, 22 Jan 2003 13:56:41 -0700

The Winder/Motor-M has a high power circuit and a low power circuit. 
When the shutter is released, the wind mechanism is released and the 
high power circuit engages and winds the camera. When the camera is 
finished winding the wind mechanism locks (the coupling stops rotating) 
and the Winder/Motor switches to the low power circuit until the wind 
mechanism is free to turn again.

On the Winder-M the motor mounts in a craddle that allows the motor to 
rotate slightly when it under high load (wind mechanism locked). This 
rotation is used to switch between the high and low power circuits. It 
is frequently out of adjustment and knocks the stuffing out of the 
sophisticated damping mechanism (a bit of high density foam) and the 
winder literally jumps in your hand. This quickly tires the foam and, 
in addition to the jumping, the winder now starts clanking somewhat 
like a heavy machine gun. It is easy to adjust the Winder so that it is 
quiet and hardly even vibrates at all; however, I have NEVER found one 
adjust that way. They ALL have required readjustment.

I do not know what switches the Motor-M from high to low power. As long 
as it works and stays quiet, who cares?

The problems arise when the wind mechanism is released before the 
shutter has finished its cycle. THIS IS NOT UNCOMMON and whether you 
use a Winder-M or a Motor-M makes NO difference. The greatest risk of 
the this happening is when you are using the slow speeds below 1/50. 
Above that the shutter USUALLY (I have seen problems then too) has time 
to complete its cycle no matter how much of a hurry the Winder/Motor is 
in. So...

DO NOT SHOOT CONTINUOUSLY WHEN USING THE SLOWER SPEEDS

John Collier

On Tuesday, January 21, 2003, at 05:03 PM, Austin Franklin wrote:

> I believe the M motor's operation has to do with the way it tells that 
> the
> shot has been fired.  I THINK it keeps a little tension on the drive
> mechanism, and when the shutter releases, the tension is then 
> "decreased"
> (probably entirely removed, save friction), and the motor senses that 
> and
> winds a prescribed "distance", which seems to be precisely 360...  I 
> wonder
> if it has enough of a delay for the slow shutter speeds.  I'll see 
> what the
> manual for it says.

- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html