Servo Speed

[AndrewHibberd]

I am currently working my way up to lipos and would like to know how fast a Sd200 servo would do 60 degrees at 8.4V

If you double the voltage, you also double the current that the motor can draw. If your battery can put out that much current, and your electronics can handle it, you will get four times the horsepower by doubling the voltage. The RPM of the motor will also be doubled and the motor will get four times as hot, (heating is proportional to current squared).

So ....A little less than twice as fast seeing as how the std voltage is 4.8v ....Ummm ....0.08 sec ?

Simplest way to calculate it is:

4.8/ new voltage * speed per 60degrees.

i.e.
Servo takes 0.16sec to travel 60degrees
Running at 8.4v

4.8/8.4*0.16=0.0914sec/60degrees

I hope this helps

Also remenber that the batteries only start at 8.4v very quickly they will drop away from this. It is bets to use their nominal voltage which would be 3.7v per li-po cell or 7.4v.

Regards
Ian

[peterw]

Most servos are only rated up to 6 Volts and what we put them through when we use them for continuous drive is far harder than they are designed to take. I have stopped running my servos above 5 v due to the high failure rate even at 6V. I would not think of running them at 8.4v. In most cases the ability to push is limited more by grip than servo power.