Servo escs

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dcr raptor
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Servo escs

Post by dcr raptor »

I've been thinking about possibly switching out the Sabretooth that I'm currently using for some of the escs found in servos (HS81 servos to be precise) to save weight and to get everything to fit inside the frame. Would I require a capacitor to use this with a polulu 50:1 micro metal gear motor and if so, what capacitance should I use?
Also does anyone know of any other servo that may contain an esc that would be more appropriate for this sort of thing?
Remote-Controlled Dave
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Re: Servo escs

Post by Remote-Controlled Dave »

You don't NEED a capacitor if you're willing to keep the pots in place, but that can sometimes defeat the space-saving point. Most people use a couple of 2k resistors I believe, though I'm not sure in what way because I don't do technicals. lol
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Andrew_Hibberd
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Re: Servo escs

Post by Andrew_Hibberd »

You can put a 0.1uF capacitor between the motor terminals, or 2 from each motor terminal to the case to help reduce electrical noise. Having said that with the 2.4GHz that is unlikely to be a problem.

Adding a larger capacitor to the power terminals would help smooth the supply from the battery, but again as the batteries are so close to the board its not really needed.

Removing the pot and putting 2 2.2kohm resistors in an 'E' to the board will save some weight.

I have used HS81 servos for weapons before but haven't tried on 7.4V any more than 6V and you risk burning them out. For a suitable servo to take the control board from, I would take one from a HV servo as these can take 7.4V without a regulator, other people have used a bigger standard servo in the past.
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BeligerAnt
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Re: Servo escs

Post by BeligerAnt »

I wouldn't rate the chances of an HS-81 control board driving Pololu HP motors, especially on 7.4V. The boards from standard-size servos do work well with the Pololu motors however, and don't generally object to being run off 7.4V. They are significantly bigger and a few grams heavier than the HP81 boards,but at least they will last the distance:)
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