Gear down Motor or Gears?

[farmersvilleRob]

Originally Posted by pfreivald

You can. Efficiencies can vary dramatically from case to case.

What does that mean? Please help, because I don't understand*

edit: marked by asterisk

[pfreivald]

It means that how you gear a system up or down can have very different efficiencies. Case-by-case analysis is the only way I know of for determining which is best.

[farmersvilleRob]

Originally Posted by pfreivald

It means that how you gear a system up or down can have very different efficiencies. Case-by-case analysis is the only way I know of for determining which is best.

Okay thanks! so basically, even a 4:1 gear down can somehow produce way less then calculated? by http://www.gizmology.net/motors.htm

T = Ts - (N Ts ÷ Nf)

where T is the torque at the given rpm N, Ts is the stall torque, and Nf is the free rpm.

[Madison]

Some energy is lost to things like friction, heat and vibration in every stage of your gearing.

Spur gears and sprockets and chain are both very efficient if built properly -- as high as 98% or so. That means that 98% of the energy input on one end comes out the other.

Losses due to inefficiency occur at each stage of gearing -- so a system with two stages would be ( .98 * .98 ) efficient, for example.

[farmersvilleRob]

Originally Posted by Madison

Some energy is lost to things like friction, heat and vibration in every stage of your gearing.

Spur gears and sprockets and chain are both very efficient if built properly -- as high as 98% or so. That means that 98% of the energy input on one end comes out the other.

Losses due to inefficiency occur at each stage of gearing -- so a system with two stages would be ( .98 * .98 ) efficient, for example.

Cool! and... disheartening.. but, with 96% effieciency, that still falls within our range which is about a 75% wiggle room.