Outrunner or Gearbox ......... which one and why

[Fred420]

OK, very basic: which one and why?

I just got the Wildfly 3D by Hobby People while it was on sale for $19.99

I am using a E-flite 370 in my GWS Tiger Moth with a 3S/1320 TP pushing a GWS 12/8 prop.

I was told that I need to use a Direct drive Outrunner instead of a Gearbox. WHY ?????

I am going to be using the 3S/1320 TP pack. I know that it is heaver then the 750 but I like the flight times.


Thanks,
Fred

[Azarr]

It's really just a matter of preference, the outrunners are usually quieter, the inrunners are usually more efficient and versatile since you can change gear ratios to accomodate battery/prop sizes.

Azarr
www.ecubedrc.com (http://www.ecubedrc.com)

[Fly-n-3D]

I prefer outrunners. You don't have to worry about striping gears.

[NCguy]

just to add my .02 to what azarr has already said, the outrunners have a "spin up" time that makes them respond slightly slower than geared applications. This matters with some airplanes more than others. I have two foamies with outrunners and it doesnt bother me much but on larger electrics it can matter.

Also, the outrunners, which dont need a gearbox, can be less expensive than geared power systems. The larger you go the more difference it makes.

Typically, you can't run quite as large a prop with an outrunner as compared to a geared motor.

[Ron S]

NCguy is right on! It's kinda a personal prefrence! I tend to like out runners. Simple,no cogs to keep maintained,plus almost allways lighter. I run Himax 2812-0850's they have a ton of power. If fact if you hammer the throttle,from low rpm,you can actually twist the front fuse in half! I run a 11x4.7 and never want for more power. Ron:)

[Elfwreck]

Hey now,
I don't know about you guys, but I crash, I'm really very good at it too:eek:
Since I often prang on those low and slow 3d games I prefer to use a gear drive. On my little parkies I use GWS gear boxes. I prang it in, bend a shaft or snap the entire box, it's a coupla bux to fix. On my big Hacker motor it's still only about seven bux for a new shaft...
With an outrunner you can easily bend the shaft, sure you can replace *some* of them, but I've seen plenty where they bust the bearings and a few where they warp the bearing mounts in the case and even warp or break the case itself.
I'm sticking with conventional set ups with gear boxes, it's cheaper to repair.
RobII

[NCguy]

Hey now,
I don't know about you guys, but I crash, I'm really very good at it too:eek:
I'm sticking with conventional set ups with gear boxes, it's cheaper to repair.
RobII

If thats the case you should invest in a cobri gearbox to replace your gws. It has replaceable parts also but it makes the GWS gearbox look like a toy in terms of durability. It will take far more abuse.

[Elfwreck]

Hey now,
I use a Cobri gear box in my MiniFunatana with a Mega 1615-4.
Great gear box, tough as anything. However on my flat plate foamies and my MiniFlash I'll keep with the GWS set ups. They're all ready in place and the models balance well as they are. You are right aboput that gb though, nicely overbuilt:D
RobII

[Wattzup]

It's a fact; gears strip and they're not necessarily cheap to replace. But gears also give you enormous flexibility in matching your motor to the task it has to perform...run some motocalc scenarios with different gear ratios to see the effects. An outrunner basically depends on prop diameter and pitch. That's it. Well, that works fine for most models, I guess. I like outrunners because they are so quiet and there's nothing grinding away and turning $ into filings. But they're always the first to reach the scene of an accident. Awfully expensive bumpers!

It's also a fact that even the buffer zone that a gear box offers won't necessarily protect your motor. I just finished replacing the rotor on a Park 400 which suffered a bent shaft in spite of the gearbox. I guess it's pay yer money and take yer choice.

About those Cobris...what's a good source for them?

[NCguy]

About those Cobris...what's a good source for them?

There are many good sources. One real good one is the folks that make them - eflightline. They ship fast, have a good slection of gears and parts, and the shipping is cheap - maybe even free for a cobri.

http://www.e-flightline.com/

[jonnyjetprop]

Another thought. Crash an inrunner, replace the shaft or maybe te gearbox. Crash an outrunner, replace the motor.

John

[D King]

Ford or chevy? Really personal pref if you ask me.
I love cdr motors though. DD or geared there just crazy powerfull and cheap !!!! Just need to try and fly a .40 size on one! LOL.

DK

[Ron S]

It makes alot of diffrence in crash damage,if you fly outdoors over grass fields. I've drove my outrunner into the ground many times with no damage to the motor. Once straight down full bore on power. It destroyed the fuse right up to the leading edge of the wing. A little compressed air to blow the dirt out of the motor,and a little oil on the bearings,and it was good as new! I think where you fly,and how you crash has alot to do with motor damage. Once I learned how to crash,( I know it sounds bad)I've done alot less damage to my planes. If you fly over a grass field,and cut the power when you get into trouble you will find that you will have much less damage to your plane,and motor. I used to fly over asphalt parking lots. There was allways alot of damage to the plane,and running gear! Since I've learned to chop the throttle when I get into trouble,the damage has been alot less(mostly the plane) a little foam safe CA,and your back to flying in a couple of minutes!;)

[Slent thndr]

Another thought. Crash an inrunner, replace the shaft or maybe te gearbox. Crash an outrunner, replace the motor.
Most outrunners come with extra motor shafts that can be installed in less than a minute. If the shaft breaks/bends just put in a new one… faster and cheaper than buying new gearboxes. Someone mentioned spin-up time earlier in this thread and I would like to just clarify that that is actually minimal (less than 1 sec for 0% to 100% throttle I think), and really shouldn’t be a big problem.

I am a fan of the ‘Hacker’ Outrunners. I just bought a Hacker A20 20L for my Formosa. I hear it’s perfect for that plane. Outrunners are quieter, and there is no hassle with the gearboxes. I would use them if you can.

The Hacker A20 20L in my Formosa will probably be just as powerful as a geared Himax 2025-5300, and cost roughly the same. Some apps require an inrunner, like in a Combat Wing. But if possible use an outrunner.

[Wattzup]

I've got a Hacker A20-20L; got it for a Mini Super Sportster and man, did it ever perform! That plane is sidelined for a while, speaking of bad landings; I recently stuck the Hacker onto my Slo Stik and I'm honestly afraid to fly it! I've used an E-Flite Park 400 for that plane and it was great, but the Hacker just pours out incredible thrust, it really seems to put the 400 to shame. I haven't flown that combo yet...I think it would rip the wings right off! Great motor!

[MiniBuzz]

With the Hacker and Himax outrunners you can replace the shafts fairly easily and parts are readily available. It's hard to beat the power of and inrunner, but the outrunners are quiet and easy. The trick is choosing the right one for your plane.

[Elfwreck]

Hey now,
I'll admit that I own a couple of out runners, little Eflite 370s, they're very nice, quiet, and fairly powerful, but they're really one trick ponies.
My small inrunners can fly a wider variety of models because I can play with the ratios. I like that. I like to experiment with scratch building different models and I couldn't afford to buy a lot of different motors, and designing everything to one size gets boring.
I can make a micro racer, scale warbird, pattern model, or even 3d all by just changing or eliminating the gear box. Can't do that with the outrunner. Eh, six of one, half dozen of the other...
RobII