[RecycledHumanoid]

Howdy Funseekers,

I'm not a very violent type of guy, so I need some advice on gear lashing. Do I pull the gears out and slap them with a belt or just toss them in a blender and push puree?

What is Gear Lashing and how do you do it?

Thanks,
Kenny

The World's One and Only Cross-Scale Recycled Humanoid!

 

[Difflock]

I'm not entirely sure what the term gear lashing means, apart from slapping them as you said

I know about backlash - the amount of play between gears, but lashing? No, sorry

Hopefully one of our more learned colleagues may shed light on it.

Mark.

 

[Fergy]

"Lashing" does indeed mean the amount of free play between pinion and crown (contrate) or spur gear. There needs to be a tiny amount of "slack" between the gears but only the tiniest amount! Enough space for lubricant and that's about it! Obviously a little extra if the gear (axle gear) isn't perfectly round - always set for the tightest mesh point. On inline-motored cars, you move the crown(contrate) gear on the axle to set this. On sidewinders, you must move the motor (or shim it) to set the gap. On anglewinders, you can do both. I like to use a very thin strip of paper between the gears to set up my lash. Too tight and friction will rob power, create gear wear, and overheat the motor. Too loose and the gear teeth will wear rapidly against one another.

 

[Ecurie Martini]

When I am using metal gears, I like to set them up fairly tight, smear them liberally with toothpaste and run them for several hours at low speed - 4-5 volts and then do my final adjustment. A dollar bill is often reccommended as the appropriate test strip. This won't work for plastic gears but, in the case of a plastic crown running on a metal pinion, another tactic is to run the gears and hold the flame of a butane cigarette lighter just below the crown gear - this takes a little trial and error and can result in a gooey mess or burning gearset but properly done it works well.

I have a metered bench supply that I use for this work and judge the effectiveness of the run-in by monitoring the current. It is not uncommon to see a 30% drop in current draw as the gears bed in.

EM

 

[Difflock]

I looked in to that burning ring of fire
I went down, down, down
as the flames went higher...etc.

Sound like fun - burning transmissions!

Thanks for putting us straight guys

Mark.

 

[Fergy]

QUOTE Sound like fun - burning transmissions!

Why do you think his last name was "Cash"?

EM's flame trick does work well. I didn't mention it because getting it wrong can be... well, wrong!

Keep the flame well below the gears.... let the heat above the flame do the work. Keep the gears in motion! And be prepared for a few failures until you get it right!