Which pinion?

[Paratrooper]

Got all my parts for my EXI T450 build and noticed I have two pinions that came with my motor.  Which one am I supposed to install?  11T or 13T?

This motor -
http://www.xheli.com/450hed23543o.html

This heli -
http://www.xheli.com/exitsecaedhe.html

Thanks guys

[Serendipity]

If your a new/in-experienced pilot......start with the 11t pinion.....the 13t will increase the head speed and require a little  more advanced blade pitch settings...although will work quite well for sport flying once you get the feel for consistant hovering and ff flight..........If using 2200mAh 20c battery the 11t pinion will be plenty to handle until you have command of the heli.....switch to the 13t........you'll be ready by then and quite pleased.........

[chris.7935]

If your a new/in-experienced pilot......start with the 11t pinion.....the 13t will increase the head speed and require a little  more advanced blade pitch settings...although will work quite well for sport flying once you get the feel for consistant hovering and ff flight..........If using 2200mAh 20c battery the 11t pinion will be plenty to handle until you have command of the heli.....switch to the 13t........you'll be ready by then and quite pleased.........

I would say the opposite. More head speed = a more stable heli. You can dial down the pitch curve in the begining to make it easier. I would only use the 11t if you have a 4cell battery.  ( I do like fast head though - Might justt be me) 

[lowbudget]

 i believe the 11 tooth would not give you enough head speed - it seams a 12 tooth would be better 

[shizack]

3500 kv motor.  I would recommend the 11T.  That'll still keep the headspeed upwards of 2700 rpm.  Plenty for a beginner to early intermediate.  The 13T will put the headspeed above 3000 rpm.  Only experienced pilots with a properly equipped and well set-up machine should be in this territory.

Of course you could run a lower (76% and below) throttle curve, but you would risk overheating the ESC and possibly the battery.

IMO; YMMV.

[dditch66]

+1 on 11T for novice and 12T for Intermediate +

11t with near 100% throttle curve will yeild longest flight times with moderate responsiveness.

[idleup]

I have the same motor with 11T in my EXI 450 plastic version 2, plenty of power to fly around.

Video and setup link: http://www.rcdiscuss.com/index.php/topic,16914.0.html

[hawk iv]

11t is a good start for a beginner
12t increases your head speed by 10% = more stable hover & ff flight but, your bird will react much faster to any stick input, also draw on your bat is increased = heat issues, and shorter flight time

[mckrackin]

I agree with 11T for beginners.
I would jump up a couple teeth as soon as you get to hovering and landing without crashing though.
Faster headspeed makes a heli more stable to a degree but it also makes it more responsive and a beginner will want a little lag in the sticks.

[chris.7935]

I was starting to think I was crazy for flying with a 13t. Anything less seems so sluggish.

I got another question. How much does altitude play in to required head speed? If I fly at 4700 ft how much faster will my head need to be for the same lift as I would get at sea level?

[mckrackin]

Altitude calls for more blade surface and pitch.
Higher headspeed will help but some wide blades are even more help when you get way above sea level.