Re: Looking for 360 degree (only) Servo

> tnx, but the common "360 servo mod" is to turn the servo into geared > reversible DC motor, easily controlled via a standard RC receiver. the > geard potentiometer is replace with a resister bridge. I want position > controlled nearly 360 degree movement. That takes a specially built > single turn potentiometer or a multi-turn potentiometer with just the > right resistance range. > > As for the question about what I want to do - I've spent a lot of time > thinking about good ways to do this - and finding the right servo if it > exists is the simplest solution. Changing out the pot in the servo with > a different multi-turn one with the right resistance range to get just > over one turn would be the next best solution. What am I trying to make > - well think light weight pan tilt zoom - except most PTZ units only > rotate around 180 degrees. >

do you need control in the form of a servo? as most pan tilt units only have on off motor control and they stay were you put them using no power

Reply to
Kevin Russell
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I was thinking in terms of using only one revolution of a multi turn winch servo. In order to have full deflection of the transmitter stick equal only one revolution of the servo the input to the PIC would be translated to the necessary output pulses to the servo. For example say for the servo given pulse width from 1 to 2 ms = 7 revolutions so one revolution would be from 1 to 1.14 ms (or any similar range within 1~2ms) So for 1ms input the PIC output would be

1ms and for 2ms input, output would be 1.14 ms. Intermediate values would be proportionate. This is just a suggestion of the logic. I have only a brushing familiarity with the process.

John Hawkins - From Canada's Atlantic Coast

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Reply to
John Hawkins

I had this same problem with rotating gun turrets on a model warship. The solution I ended up using was to mount an arm on the servo with fishing line or similar tied to the ends to the ends, the loop formed is wound on a drum, the camera mounted on the drum, this has the advantage of being light. Another solution is to use a 3:1 or 4:1 gear ratio the larger gear mounted on the servo, but this requires much more precision, or maybe a large pulley on the servo driving a small pulley on the camera's rotation shaft.



Reply to

I don't know about modern servo amps, but the amps I built for my Royal Classic system kit DID work that way. The servos could be modified to sweep up to 250 degrees by CHANGING the values of the fixed resistors on either side of the pot ! ! ! ! !


Reply to
David AMA40795 / KC5UH

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