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Author Topic: micro linear servos  (Read 4788 times)

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Offline AdminTopic starter

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micro linear servos
« on: February 08, 2007, 03:28:06 PM »
anyone know where i can find micro-sized linear servos?

i have this one:
http://www.wes-technik.de/English/light_ng.htm

it basically does what i want, but i want something faster with equal or higher force.

Offline JonHylands

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Re: micro linear servos
« Reply #1 on: February 08, 2007, 03:38:43 PM »
I've got a design worked out for a micro series elastic actuator...

It wouldn't take much work to convert it into a straight linear actuator.

http://www.bioloid.info/Micro-SEA-01.PNG

Size-wise, its 59mm center to center on the mounting points fully closed, and it provides 20mm of travel (probably 25 if we remove the spring harness).

The motor is this one:

http://www.robotshop.ca/home/products/robot-parts/motors/gear-motors/gear-motors-3mm-shaft/solarbotics-gm14-gear-motor.html

minus the gearhead. The real trick is getting a pulley mounted to motor shaft. Alternately, you could use gears. The threadscrew is #4-40 stock.

I'm not aware of any commercial servos that are linear, other than those three...

- Jon

Offline AdminTopic starter

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Re: micro linear servos
« Reply #2 on: February 08, 2007, 03:50:58 PM »
i bought that motor like 2 years ago for my jesus lizard robot . . . at the time it cost me $40 . . . im amazed how the price dropped 50% . . .

what are the dimensions on your design? it looks like 4x bigger than im allowed in my robot . . . im trying to make my robot fish smaller, but it appears ive reached what is possible given current servo technology on the market . . .

btw, ill post the complete design of my robot fish fin on SoR in about a month. the actual fish probably not for another year . . . must wait for journals to publish this stuff . . . for a change, you guys will know why ive been asking the weirdest questions for the last 1.5 years . . .

Offline dunk

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Re: micro linear servos
« Reply #3 on: February 08, 2007, 05:40:07 PM »
again, i think they will all be to big for your project but have you thought about boat Autohelm linear drive servos that are used on small craft with tiller type steering?

i've never seen one smaller than about a foot unextended.

dunk.

Offline JonHylands

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Re: micro linear servos
« Reply #4 on: February 08, 2007, 11:43:52 PM »
Admin,

How small does your servo need to be?

Without spending a lot of money on better quality motors, you're going to be hard-pressed to get faster without sacrificing power.

- Jon

 


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