Grasshopper gearbox

[JimBear]

Just thought about it the other day - was there ever a metal gears hop-up option for the Grasshopper gearbox? The 380 motor is smaller, so maybe stripping gears was never an issue?

[Saito2]

To the best of my knowledge, no. That particular gearbox used in other 540 powered vehicles like the Hornet, Lunch Box and Midnight Pumpkin has proven to be be one of Tamiya's most durable gearboxes over the many years.

[JimBear]

The idea came to my mind because I've passed by some aftermarket upgrades to the Lunch Box gears, and having a bit o' metal in the Mad Fighter gearbox - it just got me thinking. But thinking about it, given how many 'hoppers there are out there still hopping, I see why it was never needed.

[Kowalski86]

There never was a metal upgrade afaik, but it's not needed either. As old as of a design that gearbox is you can put a modern brushless system in it and it won't complain.

I've re-built several used CW-01, Hornet/Hopper gearboxes just to re-grease and add bearings. The gears were always in good shape.

[Mokei Kagaku]

3 hours ago, Kowalski86 said:

There never was a metal upgrade afaik, but it's not needed either. As old as of a design that gearbox is you can put a modern brushless system in it and it won't complain.

I've re-built several used CW-01, Hornet/Hopper gearboxes just to re-grease and add bearings. The gears were always in good shape.

I fully agree, but the aftermarket offers steel/aluminium alternatives for the housing and gears: RC Pieces CW-01 gearbox

[Kowalski86]

50 minutes ago, Mokei Kagaku said:

I fully agree, but the aftermarket offers steel/aluminium alternatives for the housing and gears

I can't imagine that having any real benefit to be honest, metal gears in a Hopper means more weight/drivetrain loss. The plastic housings are generally robust (and a CW-01 housing is a very cheap, compatible upgrade).

[Juggular]

This reminds me of a Boeing engineer's story.  He needed a gear that spools up really fast, like 10,000 RPM.  He tried all kinds of material, aluminum, steel, titanium... all failed, teeth flying everywhere.  In the end, he chose nylon, just like Tamiya gears.  A lighter and flexible gear that gives a little was the solution. 

If you want to strengthen the gears, you could swap in a steel pinion.  That gear sees the most RPM.  Aluminum or brass pinions tend to wear out.  (Perhaps nylon might be better there too, but since it gives a little, the grub screw would not secure it firmly to the shaft of the motor.)

 

[Saito2]

4 hours ago, Mokei Kagaku said:

I fully agree, but the aftermarket offers steel/aluminium alternatives for the housing and gears: RC Pieces CW-01 gearbox

Fascinating. I had no idea and do stand corrected. Aside from RC pulling applications (which the spool/locked out diff would support) I can not understand the purpose behind making the parts considering the durability record that gearbox has as being one of Tamiya's strongest. Cool parts nevertheless. Thanks for the info!

 

[El Gecko]

I'll just leave these here....

[Saito2]

32 minutes ago, El Gecko said:

I'll just leave these here....

What did you do!?   tisk tisk 

[El Gecko]

5 hours ago, Saito2 said:

What did you do!?   tisk tisk 

I was "just driving along"

*not really... The top one was from a front-flip wreck, it landed on both rear wheels equally but I still had a bit of throttle on, and the force had nowhere to go but kablooey. The screwdriver is just there to push it apart for the pic, I was surprised that the one gear cracked in 3 different places! It was cold out which probably didn't help.

The second time, I had some grippy-ish tires installed for tarmac, and while I was hooning around it nearly went into a traction roll, but as I brought it down, I had too much throttle on (again!) and it split the side gear. Luckily I had that gear left over from the new gearset to fix the first incident.

But, they've been flawless since then, and I wouldn't hesitate to get another set of plastic gears down the line if I should happen to destroy these, but so far so good. My original Grasshopper and Hornet are still on their original gearsets (as far as I know) and they've never shown any signs of weakness.

That spool looks pretty cool though. I would definitely consider something like that if I had a Lunchbox or Pumpkin that I wanted to drive on the trails or the beach.

[Juggular]

That reminds me of seeing someone using a tub of automotive grease.  Petroleum products could crack plastic gears.  (Years ago, I did use automotive grease. What a mistake that was!) 

I was also in the "more is better" camp then.  That wasn't good either.  Making the gears swim through peanut butter at every turn is not going to help them move better.  It can kill the performance gain from all the ball bearings.  Less is better.  

 

[finder75]

The all alloy gearbox and gears/spool seems definately overkill , but very very cool overkill 😁 I think the entire grasshopper type chassis can be made from 3rd party alloy offerings , chassis , front arms the lot.... not inexpensive though 🤔 imagine a Tamiya hornet where the only Tamiya part is the body 🤯 😁 I bet that gearbox would sooner wrinkle the Earths crust behind the wheels than slip a tooth 😂