how much of an impact does servo size make?

[Marzipan]

I'm looking at the MinimumRC Fan-Jet and Fly-Cat and they have options to come as plane w/ EDF, or plane, EDF & servo's and I'm wondering how much of a difference there would be if you went with a lighter or heavier servo than the 1.7g they specify.

edit - I do understand that perhaps a lighter servo won't have the power / strength to manage the control surface movements, but perhaps there are a sub-set of options that twitch much higher than their weight class? not so sure about how heavier would affect though, aside from the added weight which could affect flight characteristics...but would 2x 1.9g servo's do that vs the 1.7g recommended?

 

[Merv]

...but would 2x 1.9g servo's do that vs the 1.7g recommended?

The weight difference is negligible, they will work fine.
The type & amount of glue you use will affect the weight more.

 

[Jade_Monkey07]

I've been using those same 1.7g servos on all my builds. They even hold up on my 500mm me163 at 130 kph. They seem to have no issues pulling their weight. I havnt seen anything lighter besides the ultra micro coil based ones. And they require a specific board to run them.

 

[Jade_Monkey07]

Have you bought any parts yet? Or are you still shopping?

 

[Marzipan]

Have you bought any parts yet? Or are you still shopping?

still shopping...no monies.

 

[Piotrsko]

There's a torque spec for servos. Ive seen them sit pretty much the same for the last few years sooo if the lbft is the same the servo will pretty much perform the same for a while excluding temperature or current rise