Re: Auxliiary capping shutter for pinhole camera

[Andrew Davidhazy <andpph@xxxxxxx>]

James,

That would work but one motor is sufficient because it can be made to turn clockwise and later counterclockwise ... lifting the blade mask going CW and then moving it back to its original position when powered to go CCW.

Andy 

On Jun 4, 2013, at 1:28 PM, James Schenken wrote:

Andy,

 

That means if I understand correctly, that one motor can be set up to go clockwise and the other counterclockwise (different polarity).

Then the shutter can be set up to have sufficient friction to not move while  not actually being driven and with a connector that can be driven in either direction depending on which motor has power.   That would give a positive open and a positive close depending which motor has power.

 

Is that right?

 

James

 

From: owner-photoforum@xxxxxxxxxxxxxxxxxx [mailto:owner-photoforum@xxxxxxxxxxxxxxxxxx] On Behalf Of Andrew Davidhazy
Sent: Tuesday, June 04, 2013 1:20 PM
To: List for Photo/Imaging Educators - Professionals - Students
Subject: Re: Auxliiary capping shutter for pinhole camera

 

James,

 

The motors turn cw or ccw depending on the polarity of the input. They are not "proportional" and go full tilt when energized. 

So either the forward/reverse control can be used or the left/right turn motor can be used. They essentially do the same thing. When on the vehicle the steering control has a spring included such that when power is removed it brings the wheels back to a central position. 

 

The motors tun quite freely when unpowered. That is what made me thing of using a "drag" system to stop the mask from falling back to its perpendicular position once the motor was unpowered for the duration of the exposure. This save battery energy. If I had not done this then the mask would fall back on its own if motor was left unpowered.

 

Not sure I answered all your questions ... let me know!

 

Andy