### Author Topic: servo motor fr arm  (Read 2159 times)

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#### vivek

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• Posts: 3
##### servo motor fr arm
« on: August 29, 2008, 10:18:00 AM »
hey guys.. im doin a pick n place robot in whch me plannin to use a futaba s3001 servo fr the arm.. bt the arm is quite big like 60 cms and it has to hold a weight of 300 gms
my question is wud it be able to sustain tat much torque.. i went thru the formulae bt specifically askin this coz the length of the arm is quite large..

n in the specifications of the servo it said Weight: 1.6oz (45.1g)
Torque: 33.3 oz-in at 4.8V , 41.6 oz-in. at 6V

#### Rebelgium

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##### Re: servo motor fr arm
« Reply #1 on: August 29, 2008, 11:57:56 AM »
There's a calculator on this site somewhere in the tutorial section.
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#### ArcMan

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##### Re: servo motor fr arm
« Reply #2 on: August 29, 2008, 11:59:34 AM »
hey guys.. im doin a pick n place robot in whch me plannin to use a futaba s3001 servo fr the arm.. bt the arm is quite big like 60 cms and it has to hold a weight of 300 gms
my question is wud it be able to sustain tat much torque.. i went thru the formulae bt specifically askin this coz the length of the arm is quite large..

n in the specifications of the servo it said Weight: 1.6oz (45.1g)
Torque: 33.3 oz-in at 4.8V , 41.6 oz-in. at 6V

Well, you need 18,000 g-cm of torque to lift the load vertically.  That's 250 oz-in, which far exceeds the 41.6 oz-in of torque that your servo provides.  I suggest going to someplace like Servocity.  Look through their tables to find the servos with at least 250 oz-in of torque.  I've got a couple of the HiTec 1/4 scale servos that have 343 oz-in of torque.  Those would do the job nicely.

#### MarkBrown

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• Posts: 77
##### Re: servo motor fr arm
« Reply #3 on: August 29, 2008, 06:25:27 PM »
You could also use levers and pullies to multiply the amount of torque the servo will handle.  This is done often with larger size remote control helicptors.  Mechanical linkages are put in place to leverage the servos power to the helis swash plate.  Not sure if this is possible with your design, but is something to consider.

Mark
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#### vivek

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• Posts: 3
##### Re: servo motor fr arm
« Reply #4 on: September 01, 2008, 09:42:47 AM »
thanks a ton fr the reply guys! we are supposed to design an arm to act like a crane i.e to pick n place objects from one side to the other and one rule is somewhat like reduce weight n increase number of links to get more points

so any ideas on these lines wud b deeply appreciated.. i'd post the picture of the design we thought of as soon i finish drawin it on paint..

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