Monday, August 12, 2019
Improving Tomix "Second Generation" mechanisms (part 2)
In a previous entry, Improving Tomix "Second Generation" mechanisms, I provided a suggestion to improve the mechanism of these models by applying tape to the worm gear case to stop it vibrating against the chassis.
A year older and wiser, I've since discovered that while this mitigates the underlying issue somewhat, it's not a particularly effective solution.
The underlying issue, it turns out, is the interaction between worm gear and worm gear case - without sufficient lubrication, the worm gear will cause the case to vibrate, and sometimes "stick" slightly, causing the car to stutter, and possibly put more strain on the motor/and or cause a higher current draw than it should do.
The solution is simple, effective and obvious: lubricate the interface between worm gear and worm gear case.
Using a toothpick/cocktail stick I applied dabs of grease to the "tunnels" on inside of the case (above right) and to the worm gear itself one either end where it rotates against the case. Excess can be remove with the toothpick, and wiped on the exposed part of the worm gear (though this really doesn't need much lubrication).
Before doing that however, it's worth cleaning both worm gear and the case, to remove any existing grease/oil residue, and in the case of the worm gear, remove any built-up fibre which may have ended up wrapped around it (quite common with second-hand stock, and something I evidently missed last time).