How to get more from your Heng Long tank's plastic gearbox
By wackywheelz
BACKGROUND:
When 1/16 Heng Long tanks first hit the market, long before Smoke and Sound
and metal upgrades, they had plastic clutchless gearboxes usually with bright/fluoro
gears and spacers (see pics) and drove "as good as metal" but lacked the
increased noise and perhaps long-term longetivity of metal gearboxes. Later
they switched to the white-gear plastic gearboxes which an integrated a clutch
mechanism - a slipper clutch - into first gear, which was said to "save the
motors and boards from the increased strain if the tank encounters excess
resistance (and the driver doesn't let off the throttle)" resulting in the
motors stalling and causing chaos on the circuit boards.
Whilst this safety measure no doubt works, the downside is that some slipper
clutches are very sensitive (like my Pershing) and may engage while doing
a basic low-resistance turns on concrete or grass, something it should and
would normally be able to do but with a sensitive slipper clutch you get
"cli-cli-brrrrrr" (sounds like teeth slipping, but really isn't) until you
let off the throttle. This is caused by the slipper clutch engaging - letting
the inner part of 1st gear remain stationary while the motor continues to
spin the outer portion of 1st gear. Metal gearboxes lack the slipper clutch
(and therefor the "safety measure").
THIS GUIDE:
My aim, and the aim of this guide, is making the plastic gearbox with slipper-clutch
behave and run just like the original decent Heng Long plastic gearboxes
or like a silent set of metal gearboxes - by allowing your tank to use its
available torque and power without the slipper clutch ever jumping in and
ruining the fun. This mod is no more risky than running metal gearboxes (which
are common and very popular), we're disabling the clutch mechanism -
very handy for an overall increase in driveability on all terrain,
climbing steep inclines or pulling excess weight.
WHAT YOU WILL NEED:
- phillips head screwdriver
- 2-part epoxy OR superglue (aka Cyanoacrylate/CA)
I was planning to do a much more detailed guide tailored to suit each tank,
but for now this will do:
(1) The basic idea is to undo your tank, remove the gearboxes, partially
disassemble your gearboxes (all straightforward, use my pics above for reassembly).
(2) With the "1st gear" (the one that makes contact with the metal pinion/little
gear on the motor) removed and looking like the last pic above (in 2 pieces,
inner and outer) you apply superglue or epoxy to the inside face of the bigger
gear then place the inner gear back inside the outergear, pushing them together
for a good bond (do not get glue on the teeth).
(3) Once dry/set, reassemble everything and you're done - enjoy your modified
tankand its unlocked pulling power!!
