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RC Equipments => Electric Power => Topic started by: tg on March 30, 2009, 07:50:09 PM



Title: Gear boxes for outrunners
Post by: tg on March 30, 2009, 07:50:09 PM
Hi,
    Is it possible to use a gearbox for an outrunner to turn a large prop? I've got a 2212-13 and would like to try out some large props than what may be recommended. Has anyone tried this out?


Title: Re: Gear boxes for outrunners
Post by: izmile on March 30, 2009, 09:37:25 PM
Tg,

It should be possible. But note that outrunners have a greater torque so it will wear off the gearbox pretty quickly. You may need to have a metal gear and/or do a soft start and a soft braking.

-Ismail


Title: Re: Gear boxes for outrunners
Post by: Rao on March 31, 2009, 04:43:52 PM
Why fit a gearbox to an outrunner.One of the advantages of outrunner motors is their ability to turn large propellors without using gearboxes.


Title: Re: Gear boxes for outrunners
Post by: rcforall on March 31, 2009, 04:48:35 PM
Hi,
    Is it possible to use a gearbox for an outrunner to turn a large prop? I've got a 2212-13 and would like to try out some large props than what may be recommended. Has anyone tried this out?


What is the prop size you want to turn ?


Title: Re: Gear boxes for outrunners
Post by: chanvivek on March 31, 2009, 05:20:10 PM
Talking out of personal experience, I have used the same motor on a Christen Eagel bipe.  I was spinning a 10 x 4.7 SF GWS prop on a 11.1V Lipo.  The motor was getting warm when i was flying hard.  But even if you use a gearbox, and try turning a bigger prop on this motor, the efficiency might not be very high.  The 10 x 4.7 by itself is a big prop for this range of motors.  You might try it on a 11 x 4.7 also.  But be careful not to rip the motor hard.  Full throttle for verticals is fine but care should be taken and full throttle should not be used for the entire sortie.  If you want to turn a bigger prop, better go in for the next size of outrunners.  Now am planning on the 2217 motor for a 11x4.7 prop for my Hyperion 3-Delight which was also tested with the 2212-13.  Changing the motor for better thrust!

Regards,
Chan


Title: Re: Gear boxes for outrunners
Post by: tg on March 31, 2009, 05:37:31 PM
Sai,
   A 11x4.7 is what I was going to try. I have to date tried a 10x6 and smaller props. Was thinking that anything bigger will be a problem and hence the question.



Title: Re: Gear boxes for outrunners
Post by: chanvivek on March 31, 2009, 05:49:03 PM
Sai,
   A 11x4.7 is what I was going to try. I have to date tried a 10x6 and smaller props. Was thinking that anything bigger will be a problem and hence the question.



You can try a 11x4.7 on it.  Or if you can wait a bit, i would test it in my setup and get you the results!  But be sure not to push the motor very hard!

Chan


Title: Re: Gear boxes for outrunners
Post by: rcforall on March 31, 2009, 05:51:44 PM
TG ,
You can use 11 x 4.7 on a 2212/13
sai


Title: Re: Gear boxes for outrunners
Post by: tg on March 31, 2009, 06:11:04 PM
Sai, Chan,
   Thanks for the help. Also what is a good prop size for a 2217?


Title: Re: Gear boxes for outrunners
Post by: chanvivek on March 31, 2009, 08:25:42 PM
The 11 x 4.7 should be a snug fit for the 2212-17.  Try 10x7 for speed and

11x5 or 11x4.7 for 3D.

I use 10x7 APC for my electric .25 size Seduction and it rocks!!

Chan