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Fitting Pintopower's no-need-for-a-3rd-shock-mod transmission retainer

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Ok this one is awesome. Installed and tested with full articulation to the left and right.

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I think the installation is really neat and tidy. I thought it was going to be very obtrusive for some reason.

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I need to order one from shapeways to confirm tolerances and then i'll make a thread in the TC Designs area about how to get one. Thanks for the suggestion! My lunchbox has never been happier!

By the way, guess who is next...

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Fantastic. Researching lunchbox deals now

Oh dear. I'm sorry.

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You know, if this piece was altered to extend to match the width of the chassis tub installation could be simplified. Rather than drilling the battery box to locate the mounting screws the nerf bar screws could be replaced with longer ones. The longer screws would be more than enough to support the mod.

03.15.2016-14.36.png

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:) Also I thought of a good mod also that can be done to improve two problems with one small part.

if he made a raised lip on the side directly behind the battery pull UP tab on the inside half of it from the cut side to about the letter U on the tab half way.... it would stop the battery lid from falling off all the time and you could still open and lift up the tab from the outside half without the raised tab behind it..

You know, if this piece was altered to extend to match the width of the chassis tub installation could be simplified. Rather than drilling the battery box to locate the mounting screws the nerf bar screws could be replaced with longer ones. The longer screws would be more than enough to support the mod.

03.15.2016-14.36.png

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You know, if this piece was altered to extend to match the width of the chassis tub installation could be simplified. Rather than drilling the battery box to locate the mounting screws the nerf bar screws could be replaced with longer ones. The longer screws would be more than enough to support the mod.

03.15.2016-14.36.png

I did initially think of this but its really hard to get a screw in there. Plus those sloped ribs mean I need to thin out the brace around them. I dont think it will weaken it considering how the loads are applied though. its not a bad idea.

:) Also I thought of a good mod also that can be done to improve two problems with one small part.

if he made a raised lip on the side directly behind the battery pull UP tab on the inside half of it from the cut side to about the letter U on the tab half way.... it would stop the battery lid from falling off all the time and you could still open and lift up the tab from the outside half without the raised tab behind it..

Hmmm....I like that. The brace was initially designed to do away with the battery door all together. It is supposed to look like this:

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This mod was the idea for the brace but now it is looking like it has become much more useful than I thought.

Thanks for the info folks!

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:) Your welcome.

See this photo I moded...In red that's what you need to add raised up so the battery cover will stay in place.

DSC05672_zpsmjoyprir.jpg

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Sorry to dig up an ancient thread but I was reading the debate between having the gearbox right at the bottom of the slots vs halfway.

I understand the reasoning that having it midway allows one side to go up and the other to go down but wouldn't that also mean you lose 50% of the upwards travel because you are already halfway up the slot before anything even happens?

I guess it's all about compromises but don't people usually optimise suspension for upstroke vs downstroke? 

I guess neither way is the "right way" I suppose having it half way is sort of like when you have your dampers set so the suspension sits at half travel just from the vehicles own weight so that the wheels can move up over bumps but also down into voids in the surface.

 

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The slot shouldn't be considered suspension travel. The pivoting action of the axle in the slot facilitates suspension travel, which the shocks control. Having the transmission brace in the halfway position allows articulation which is slightly different, but still essential to get better performance out of a swing axle suspension. 

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1 hour ago, ThunderDragonCy said:

The slot shouldn't be considered suspension travel. The pivoting action of the axle in the slot facilitates suspension travel, which the shocks control. Having the transmission brace in the halfway position allows articulation which is slightly different, but still essential to get better performance out of a swing axle suspension. 

Ok I should have clarified. I suppose "articulation travel" is the most direct way to describe what I meant. It could be seen in the same way almost though, just rotated 90 degrees.

What I meant was, with the brace halfway, each side is already using up half the upwards travel of the slot and so when a wheel hits a bump it can only articulate half as much as if the brace was at the bottom. Obviously there is the benefit of the wheels being able to go down as well but I'm wondering which is more useful in real world conditions.

Is it better for the wheels to be able to sink into dips or would it be better to have twice as much upward articulation? Obviously if the wheel can move downwards then it prevents the entire chassis moving down into the dip but in the real world, people seem to spend more time going over raised obstacles.

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The wheels can still go up and down by the same amount as they would without the brace in place, as the pod pivots up and down as well as being able to twist.

The difference is that with the brace in place, all the movement is controlled by the dampers, as opposed to the stock arrangement wherein the up and down movement of the front of the gearbox happens independently of the main dampers.

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One of the most effective things suspension does is extend into dips to keep traction. Wheels tend to roll over bumps pretty well on their own but they "bridge" holes or the momentum of the vehicles tends to carry thrm over dips so extension is really important. 

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29 minutes ago, TurnipJF said:

The wheels can still go up and down by the same amount as they would without the brace in place, as the pod pivots up and down as well as being able to twist.

The difference is that with the brace in place, all the movement is controlled by the dampers, as opposed to the stock arrangement wherein the up and down movement of the front of the gearbox happens independently of the main dampers.

I mean the twist. When I say up and down I mean the pivot movement. If you start off with the two tabs/ends of the metal shaft on the front of the gearbox already halfway up the slots then each tab can only travel half as much upwards than if they started at the bottom of the slots. That means each wheel can only pivot half as much upwards but as a trade off they can also pivot down. If the brace held the tabs at the bottom then each side could't pivot upwards more but could pivot down at all. 

I was just wondering which would work better in real world terms.

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Actually, now I think of it, if you're going to have a brace then putting it in the middle is the only place it can go. Only with no brace at all can you get that full upwards pivot movement. 

When you introduce a centralised pivot, when one side goes up the other side must go down the equal amount. Without the pivot, one side can go up the full length of the slot whilst the other side pretty much stays where it is but with the obvious drawback of gearbox slap being possible. This was what I meant by being able to get a larger upwards pivot but the obvious downside is that the default position is for the whole thing to be at the bottom of the slots so the wheels cannot pivot downwards into dips.

This is why the ball pivot on the DT01 works so well, you have no slots there anymore to restrict rotational movement. It's like having a brace and also taking the slots off as well. With the Lunchbox you don't have the luxury of removing the slots so if you are going to have a brace, the area that compromises movement the least is in the middle because it allows the most possible freedom of movement up and down the slots. It can therefore be considered an improvement in two ways because it not only prevents gearbox slap but also enables downward articulation/pivoting whereas with the stock setup it is upwards only (albeit a greater amount)
 

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I worked on my Lunchbox for a while to get it to perform well. I use all of Pintopower's CW-01 parts *except* the gearbox brace (which I tried, and which did not solve the fundamental problem).

@shenlonco  has the right idea - the major problem with the suspension is that with or without Pintopower's brace, the suspension "locks open" (i.e. full extension) under power. Then the chassis tends to bounce a lot, which I didn't like.

I've seen three solutions:

- fishing line mod

- home-made four-link

- 4-link kit (which I used)

All three solve the problem by NOT allowing the gearbox to pull the rear shocks open under power.

Here's a vid showing the articulation at rather low speeds, but even at high speeds the rear suspension remains compliant. Playing it at half speed helps show the suspension doing its job.

 

 

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3 hours ago, smirk-racing said:

I worked on my Lunchbox for a while to get it to perform well. I use all of Pintopower's CW-01 parts *except* the gearbox brace (which I tried, and which did not solve the fundamental problem).

@shenlonco  has the right idea - the major problem with the suspension is that with or without Pintopower's brace, the suspension "locks open" (i.e. full extension) under power. Then the chassis tends to bounce a lot, which I didn't like.

I've seen three solutions:

- fishing line mod

- home-made four-link

- 4-link kit (which I used)

All three solve the problem by NOT allowing the gearbox to pull the rear shocks open under power.

Here's a vid showing the articulation at rather low speeds, but even at high speeds the rear suspension remains compliant. Playing it at half speed helps show the suspension doing its job.

 

 

Absoloutely agree, the brace etc won't cure the fundamental problem inherent to the design.

Grasshopper, Hornet, Lunchbox, Nikko F10, even the Tyco Jet Hopper have the same self-defeating setup where the rear just bounces up and down.

The pivoting does help when off the throttle and stuff like the brace helps to make the most of it. Also when cornering it enables the wheels to stay on the ground whereas with no pivot action (ie grasshopper) if the vehicle leans the inside wheel will come straight off the ground and rev up.

It definitely needs a total redesign to get the the suspension to work in a conventional manner though.

I've watched that video loads of times! It definitely gets it working properly.

I have several trucks I'd like to make 4-link. Just a matter of finding the time and the courage! 

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Also a matter of deciding what and where to cut, geometry, standard or parallel 4 link etc.

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I’ve just fitted one of these to my Hornet, and went for the version with the properly retained battery door. Very nicely made and easy to fit. Certainly stops the slap sound and I think improves the bouncing on uneven surfaces slightly. And of course the battery will never fall out again!

 

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