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Mechanics and Construction => Mechanics and Construction => Topic started by: Dan__ on September 03, 2013, 04:30:03 PM

Title: Servo Motor and max applied force
Post by: Dan__ on September 03, 2013, 04:30:03 PM
If I got a usual servo motor for about 20$ (with a tork of 98Ncm),
can I use it to lift a weight of 9 kg <= 90N,
by using a wheel with 1cm radius, and a thread on this wheel ?

According to this:
90N * 1cm = 90Ncm

it should work.

Can you aprove it please?
Title: Re: Servo Motor and max applied force
Post by: newInRobotics on September 04, 2013, 03:10:24 AM
Servo should be able to lift what You want with a wheel of given radius :)
Title: Re: Servo Motor and max applied force
Post by: jwatte on September 04, 2013, 09:56:13 AM
IF the servo actually achieves the rated torque, then yes, you could lift that weight with that radius (technically, any weight less than that -- if you hit the weight perfectly, then you'd just achieve equilibrium against gravity, and not actual movement.)

However:

- most hobby/consumer equipment is specified optimistically, and you're unlikely to get the full rated performance under normal usage
- what's specified is often the "stall torque" which is the maximum torque possible to get out of the motor for a short duration

If you operate this servo at that amount of load for any significant amount of time (say, more than a few seconds,) you're likely to burn the servo out at some point.

If you actually want to "lift" things by, say, winding wire on a wheel (like a winch,) you're probably better off with a DC gearmotor, geared for the load in question.