Plastic or metal gearboxes?

[SoCalBobS]

Of course the answer is metal! I just wanted to share an actual experience that corroborates this. I bought a Leclerc from DKLMRC the day it came available. I deliberately chose an all plastic version. I figured I'd get plastic tracks out of it, and I would intentionally "test it to destruction". Sure enough, after a few hours of motor run, a gearbox failed. The runs included two battle events in San Diego, where just about everything requires repair and maintenance afterwards, because we do run them rough!

As far as the Leclerc and other Tongde tanks are concerned, the good news is Motion sells the gearboxes, and they are interchangeable, except for the Chaffee, Paladin and other smaller tanks like the upcoming M113. They all use a second kind of box, but interchangeable amongst themselves.

[DavidN]

I also bought the metal sprockets too :-) I know they both (plastic gearboxes and sprockets) will fail on me soon or later.

[keilau]

The major difference among gearboxes is NOT the gear material (plastic vs metal). It is the bearings of the gear axles. Higher quality gearbox uses ball bearings on the gear axle. It is quieter, less vibration and wear. It generates less frictional heat in the gearbox, thus draws much less current from the MFU/ESC. This description applies to the Heng Xin, Mato, Taigen/Torro metal gearbox and only the top end Heng Long metal gearbox (-4 version)

It is also important to pair the gearbox with genuine Mabuchi 380 or high end 390 motor with ball bearings axle. The Tamiya standard 380 is Mabuchi motor. These motors heat up a lot less than the grey 380 motor that comes with the Heng Long gearbox.

[Evan D]

It's a system, gears, bearing'ed shafts (not just the output), the motor and, yes the output shaft of both the gear box and the tank chassis itself. I run just HL tanks and use their plain metal geared gear boxes which have bushings but I add a bearing to the output shaft on the chassis.

[keilau]

It's a system, gears, bearing'ed shafts (not just the output), the motor and, yes the output shaft of both the gear box and the tank chassis itself. I run just HL tanks and use their plain metal geared gear boxes which have bushings but I add a bearing to the output shaft on the chassis.

The drive shaft bearing is a very good way to refine the gearbox alignment to the motion vector. You can install the bearing with or without the metal housing. I prefer the metal bearing housing which reinforces the plastic chassis. The bearing does not affect the characteristic of the gearbox. Below is the gearbox output shaft ball bearing housing for the Heng Long Abrams and HL Leopard.