TOPIC:

Hi

I wanted to upgrade my re re Grasshopper to the 540 motor and was wondering what i needed to do? The manual states i need to buy an 18 tooth pinion, i already have a 540 motor that i need to wire up using the 380 original wires. is it an easy switch over has anyone tried it before?

Regards

A Silvercan was the first hop up I gave my Hopper - way way back...
Works perfectly fine with a 540. But with the handling of the car in mind I wouldn't go lower than a 23 turns.
No need for other changes but the correct (18T) pinion. Ball bearings might be advisable though.

im wanting to order the pinion online but im not sure which one to go for anyone got a link for one?

thanks

Official Tamiya pinion is #3515006 - these are the ones on eBay :

18T 0.8mod pinion

Nowadays I'd probably recommend a hardened Robinson but the 18T doesn't give a result...
But for this purpose it might not be very necessary.
If you'd like a link to a steel pinion, I'll see if I can find one that matches of course.

I used to race a 1st gen 'hopper. Only mods were a 540 silver can 540, ballraces, BRASS pinion (Anything else will shorten the life of the counter gear) & I seem to remember there was a chassis cutting mod described in the manual to enable a hump-backed 7.2v battery to be fitted (This might not be necessary on the later ones). People keep commenting on the poor handling, but mine was still running the undamped kit shocks & I regularly had good A-final results. Mine was lively enough with a standard motor. The missus has a 19t modified in her Mad bull & I can see why this would cause racers "handling problems" - it's overpowered & a task to keep it straight under hard acceleration. Anything slippery, forget it, no fun on ice at all!

I've yet to be convinced that the material the pinion is made from has any impact on spur gear life - I know it's recieved wisdom that you should not use the Tamiya aluminium pinions, but on the other hand the only times I've damaged spur gears is loosing teeth after age/wrong lubricants have embrittled them

Don't know about the direct impact on spur life either but the pinions tend to wear quite fast.
I have to say it hasn't really been a problem on my 23T Grasshopper.
What I did notice on my DF-01 is this greyish residu in the rear gearbox of which I can only conclude it's alu dust...
That would definitely shorten the lifespan of all the gears.

Btw - I ran it on ice in the eighties by converting the front tyres to spikes with pushpins.
And Holiday Buggy wheels on the rear. That was loads of fun!

As far as I know, it's like this - if you run soft components with hard components, the hard stuff always wears before the soft - look at the state of stub axles if they've been run for any length of time with plastic bearings. It's because dirt &/or tiny shards of the hard material get forced into the soft faces of the softer component & effectively form a grinding tool (Worse if there's oil & gease about as it forms a sort of grinding paste). Gears should be made from "tough" material (Tough is different to hard) & brass is a "tough" material. Aluminium is actually worse at resisting wear than plastic, & is only used for pinions because of the heat generated when running very small gears with much larger ones (To do with pressure angles & contact time of the teeth). The EN8 steel they use for steel pinions isn't usually hardened (Again to help wear resistance & shock loading, so it's more tough than hard) but once the wear begins, wearing-out happens much quicker because the steel is hard enough to "hold a cutting edge". Although brass is harder than plastic, it is quite brittle, & if sharp edges do form, they don't last long before they just break off. I would guess that titanium pinions would be just as bad as steel for their "cutting" nature, but because titanium is tougher than steel, you'd probably get more use out of them before the wear starts to set in. The most effective weapon against gear wear is to set the clearance (Backlash) properly - too much causes "Cutting out" of the gear teeth, too little causes heat, both will shorten the life of the gears