VO-BB - 20 YEARS OLD!

todd ellis · Posted: Tue Feb 01, 2011 8:11 am Post subject: more DIY input requested

well, the maiden voyage of jib-boom-enstein went off without too many hitches ... i'd give the day a B+ overall - now on to the next thing.

i'm building a remote control follow-focus.

i have the gears, motor, rails & mount (either on hand or in mind) what i'm looking for is a potentiometer that, when turned one way turns the motor & when turned the other reverses the polarity and turns the motor the OTHER way.

i've googled & googled, but clearly am not searching for the right thing.

any ideas?
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"i know philip banks": todd ellis
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todd ellis · Posted: Tue Feb 01, 2011 8:27 am Post subject:

never mind. i am an idiot. DC, you moron ... not AC. i was trying to do i t the hard way. dpdt rocker switch & a 9v battery ... thanks for the help!
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"i know philip banks": todd ellis
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Bruce · Posted: Tue Feb 01, 2011 12:21 pm Post subject:

The first thing that comes to mind is the little servos/motors they use in RC aircraft and cars, and the radio control box.

B
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VO-BB Member #31 Enlisted June, 2005

I'm not a Zoo, but over the years I've played one on radio/TV. .

Mike Sommer · Posted: Tue Feb 01, 2011 1:59 pm Post subject:

What kind of camera and what kind of lens?
Do you need zoom also?

There are many ways to do it. I've used reversible motors with friction wheels and bands as well as servos. It depends on how far the focus range and pull of the lens is.
http://www.youtube.com/watch?v=PSlcbi0GnVw&feature

THis is way cool:
http://www.youtube.com/watch?v=eq8eD9zU7p4&feature

http://www.hocusproducts.com/products.php
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The Blog:
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Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

todd ellis · Posted: Tue Feb 01, 2011 2:51 pm Post subject:

it's a canon 5d mark II, altho9ugh we COULD use it with the 7d OR the 60d - all the same - canon glass.

in the 1st link - that's EXACTLY what i'm looking for - what kind of rheostat, pot, switch is that - it reverses the polarity of the motor when turned one way or 'tother????

btw - that iphone thing is SUPER cool.
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"i know philip banks": todd ellis
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Mike Sommer · Posted: Tue Feb 01, 2011 5:58 pm Post subject:

Just mod a RC car transmitter.
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The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

todd ellis · Posted: Tue Feb 01, 2011 8:39 pm Post subject:

yeah - that looks like the way it's workin' out.
_________________
"i know philip banks": todd ellis
who's/on/1st?