Vanessa's Lunch Box - Build question

[metroplex]

Hi! I'm quite new to the RC world and I recently got myself the car of my childhood dreams - a Vanessa's Lunch Box (re-release edition).

The build process has been great fun and straight forward - except for the detail of mounting the axle shaft springs. I don't quite understand the illustration in the manual and don't really get how those little springs should be mounted. Could someone please point me in the right direction by posting a picture?

In return, I promise to post some nice pictures of my Lunch Box in action

[TA-Mark]

The little springs (BR4) are held into the pivot blocks (D7) by a small screw. They help to hold pressure onto steel shaft in the pivot of the gearbox to resist the gearbox from 'rolling'. The 'rolling' diff helps to keep both rear wheel touching the ground over uneven terrain.

Do not over-tighten the screws that hold these springs! Pinching the spring coil tight under the screw will cause the springs to break very quickly. The coil part of the spring must be loose enough that it can move freely on the shaft of the screw.

In my opinion Tamiya have missed a part here. They should use a stepped screw or have a tube over the screw to prevent it from being over-tightened.

One of the most common modifications to a Lunchbox chassis is a 3rd damper in the centre of the pivot shaft which takes alot of the pressure off these 2 small springs.

[metroplex]

The little springs (BR4) are held into the pivot blocks (D7) by a small screw. They help to hold pressure onto steel shaft in the pivot of the gearbox to resist the gearbox from 'rolling'. The 'rolling' diff helps to keep both rear wheel touching the ground over uneven terrain.

Do not over-tighten the screws that hold these springs! Pinching the spring coil tight under the screw will cause the springs to break very quickly. The coil part of the spring must be loose enough that it can move freely on the shaft of the screw.

In my opinion Tamiya have missed a part here. They should use a stepped screw or have a tube over the screw to prevent it from being over-tightened.

One of the most common modifications to a Lunchbox chassis is a 3rd damper in the centre of the pivot shaft which takes alot of the pressure off these 2 small springs.

Many thanks for your helpful answer. Unfortunately I'm still confused on how to actually mount the little spring. In the illustration is looks like the spring should be pushed into the axle shaft? Attached is a picture of how I've mounted it. This can't be correct, right?

[TA-Mark]

It simply sits ontop of the pivot shaft housing. Odd that you have a large bend in the spring.

I'll try get a close up shot of mine.

Had to pull the motor out to get it into shot. Excuse the dirt, it's one of my most driven models. This is how it should look once fitted:

[metroplex]

Ahh.. I think I understand now - what a weird little device I'll disassemble my machine and have a look right away! I'll update this thread later.

[metroplex]

Now I've fitted it like yours - it seems like a much better setup than my old one Took the van for a small test run as well, and it now also handles better than before.

One more question popped up though; in the illustration you posted from the manual, what's the purpose of the BA3 screw? This one is supposed to be removed at a later stage in the build process, right?

[TA-Mark]

One more question popped up though; in the illustration you posted from the manual, what's the purpose of the BA3 screw? This one is supposed to be removed at a later stage in the build process, right?

Correct. It's used to hold the spring out of the way until the gearbox is in place. I never used it, and still don't when working on the truck. I use a hex key through the hole to hold the springs up while I locate the gearbox. End result is the same.

[metroplex]

Correct. It's used to hold the spring out of the way until the gearbox is in place. I never used it, and still don't when working on the truck. I use a hex key through the hole to hold the springs up while I locate the gearbox. End result is the same.

Ahh, mystery solved - thank you very much for your kind help! This makes me want to build another one

[metroplex]

A little movie from my first run:

http://vimeo.com/19891722