42083 Bugatti Chiron - MODs and Improvements

[ttoobbyy]

@Didumos69 So what you mean here is, the following instruction is the only way to get right order of gearbox. The instruction from handbook of lego is incorrect?

On 2018/6/4 at 11:27 AM, Didumos69 said:

To make it work, the orange gear selectors and the 2L lever with towball should be aligned properly. The foreground of the render below shows the only correct aligment of the 4-speed gearbox with the 2L-lever with towball pointing to the upper-right side. The 4-speed gearbox is in its 4th gear. In the background of the render, the low-high gearbox is in its low gear, which corresponds with either of the two vertical gear selector positions. However, the low-high gearbox might as well have been in its high gear, which corresponds with either of the two horizontal gear selector positions. The 2L-lever with towball is in position to switch the low-high gearbox when an up-shift occurs (the right paddle shifter under the steering wheel is for up-shifting). Such an up-shift will switch the 4-speed gearbox from 4th to 1st gear. In the render, with the low-high gearbox in low gear, this means the entire gearbox is switched from 4th to 5th gear, which is the desired result. If the low-high gearbox had been in high gear, the up-shift would have resulted in an 8th to 1st shift of the complete gearbox.

The brothersbrick review shows the correct alignment. The low-high gearbox is in low gear and the 4-speed gearbox is in 4th gear.

 

[Paknaloid]

@jb70 'Pimp up your Bugatti' is underway  thanks for sharing

[Didumos69]

5 hours ago, ttoobbyy said:

@Didumos69 So what you mean here is, the following instruction is the only way to get right order of gearbox. The instruction from handbook of lego is incorrect?

Sorry, no, I have no reason to think the instructions are wrong, but it is easy to make a mistake. I probably should have made more clear what I meant with 4-speed gearbox and low-high gearbox. The complete gearbox is in fact composed from a 4-speed gearbox and a low-high gearbox. Drive flows as follows: engine -> DNR -> low-high gearbox -> 4-speed-gearbox -> front and rear axles. The 4-speed gearbox is basically the left half of the complete gearbox (in the foreground of the render). This 4-speed gearbox iterates through 4 speeds. The low-high gearbox is the right half of the complete gearbox (in the background of the render). This low-high gearbox toggles between 2 speeds; low and high. In fact it iterates through 4 positions, but its 1st and 3rd position give the same ratio and its 2nd and 4th position also give the same ratio. The 2L-lever with towball shifts the low-high gearbox once every 4 up-shifts or 4 down-shifts. So, the low-high gearbox would only iterate through all its 4 positions after 16 up-shifts, or 16 down-shifts, which effectively means the entire gearbox runs through all its 8 speeds twice. So @Sariel's conclusion it is in fact a 16-speed gearbox wasn't really wrong, only the second sequence of 8 speeds is a repetition of the first sequence of 8 speeds.

Now what I meant to say is that: When the 2L-lever with towball is pointing to the upper-right side (as in the render), then the only correct position of the 4-speed gearbox is 4th gear, which corresponds to the engaged clutch gear in the foreground of the render. That's all. The position of the low-high gearbox is irrelevant here (it only becomes relevant when a 8<->1 gearblock is added). 

PS With the explanation about the low-high gearbox, it is also more easy to understand the idea behind my (and @Appie's) suggested gearblock mod: When we would have an 8<->1 gearblock, the low-high gearbox only needs 2 of its 4 positions, because you should no longer be able to iterate through all its positions. As a consequence the low-high gearbox could do without 2 of it's clutch gears: either the two at the back side of the driving rings or the two at the front side, plus the 16t gear they mesh with, could be removed. This in turn, creates space for the gearblock itself. All-in-all you could say, the gear block creates its own space.

In the render below I removed the gears at the back side of the driving rings of the low-high gearbox. Note that the position of the perpendicular axle-pin-connector in the render indicates the wave selector should engage the upper driving ring (starting from the depicted position it can only rotate in one direction and if it does that should engage the lower driving ring). So now the position of the perpendicular axle-pin-connector and the position of the wave selector are related.

Edited June 11, 2018 by Didumos69

[Kumbbl]

1 hour ago, Paknaloid said:

@jb70 'Pimp up your Bugatti' is underway  thanks for sharing

@jb70  If you really give consideration to such a pimp-package for the bugatti (as with the Porsche) then i have  a plea: Please wait some time because i'm sure there will come up some other MODs here, at least for the Front axle (e.g. Didumous69 one or also DugaldC approach with torsion bars)... Didumous gearbox mode for a 8<-->1 box is also great... anyway: a pimp would be great, thanks already in advance ;-)

[dforce]

On 6/9/2018 at 11:13 PM, DugaldIC said:

Am I the only one to have this problem or at least notice it. With the Bugattis gearbox if the shifter is in drive the the pistons move but everytime I shift into reverse the pistons don't move at all?! Has anyone else had this issue? 

With my model, it's not that that reverse doesn't work, but rather that there is significant lag before it engages.  In my experience, a good 1.5 to 2 feet of pushing the car finally engages reverse after the switch, and the same when you return to forward.  I'm not sure where most of the lag is, but it must take a while to get through all the gears.

Also, I am about 3/4 of the way through the build and I am enjoying it immensely.  Sure it was my entire Lego budget for the year, but so worth it!

[jb70]

2 hours ago, Kumbbl said:

@jb70  If you really give consideration to such a pimp-package for the bugatti (as with the Porsche) then i have  a plea: Please wait some time because i'm sure there will come up some other MODs here, at least for the Front axle (e.g. Didumous69 one or also DugaldC approach with torsion bars)... Didumous gearbox mode for a 8<-->1 box is also great... anyway: a pimp would be great, thanks already in advance ;-)

@Kumbbl Yes, I really plan to do a pimp-package. But don‘t worry, this will take some time... And I am really looking forward to all ideas from this community!

In the next days I will try to understand, build and test @Didumos69 gearbox solution. 

I think, blocking the round-trip-gear-change is also a must-have to pimp up the bugatti and reducing friction in gearbox is always welcome.

Thankx to Didumos in advance for this great work!

[jb70]

This is a first try on the doors. A very simple door locking mechanism using only 5 additional parts per door. Not perfect yet, but better than the sloppy doors in the original one, where the doors don't have a fixed position when closed.

[kbalage]

On 6/10/2018 at 7:13 AM, DugaldIC said:

Am I the only one to have this problem or at least notice it. With the Bugattis gearbox if the shifter is in drive the the pistons move but everytime I shift into reverse the pistons don't move at all?! Has anyone else had this issue? 

It's a wild guess, but isn't it the exact opposite? When the car is in reverse the pistons move instantly. When you put it in drive due to the complex drivetrain it needs sometimes up to ~1m to roll before the pistons will actually start moving.

[ttoobbyy]

@Didumos69  Thanks, I think you made it clear enough! In fact, I am just determined to follow your idea to remove those useless gears.

[jfb9301]

Does the blue idler gear in the rear differential serve any real purpose, or can I just not build it in there? On first glance (I'm only just beginning on building this) it looks like it does nothing, and can just induce more friction.

[ttoobbyy]

One thought of the linkage between gearbox and Spoilers. This is the very first prototype. 

At first, I was thinking, if  I could achieve linkage between left side of the gear box, which is the 4 speed gearbox, the selector will turn 90 degrees every time you push the control rod. However, basically there are two difficulties. The first is there is a big gear at the back of gearbox. I am not sure if there is enough space for any other gears. The second is, the left side of car body is much compact than right side. So I ask myself if I could do the same thing at the other side.

For the right side of gearbox. It may not be able to show every movement of gearbox control rod. Since the right side will only turn 90 degrees when we push 4 times of the control rod. With the simplify modification of @Didumos69 . We can lock the gearbox at 8th speed. And between 4th and 5th speed, the right side selector will turn 90 degrees. We can use this.

The following picture just show the principle and idea. It is not the real situation!!!!!!

The green gear at right top corner connect to the right side selector. I have checked that it is on almost the same level with the control hole of spoiler. With two pair of 20:12 gears. we have 2.8 time. The selector may only turn 90 degrees while the to control the spoiler open and off. The axle need to turn about 120 degrees. The ratio is about 2.67 which is very close to what we have got now: 2.8.

The axle will pass though under shock absorber, which mean it must very close to the the car frame. With 3 universal joint we may achieve this (I don't know how to bend the universal joint in the LDD, but you can understand what I mean, right? ).

There has enough space at back right of the car body for those. So I think there won't be any problem to add all these element. Some liftarm need to be add to ensure the mount of axles. I will check this later.

 

[jb70]

@Didumos69 I have build your gearbox solution and it really works great!!! 

To make it fit into the Bugatti, I needed to made some changes:

• adjusted the gearbox housing
• I moved the blocking switch to the front, because it had a collision with the engine mounted later
• This made it possible to reverse the hi/low geartrain again (as in your first choice). Good luck, because having the 20T gears on top also collided with the engine. Having the 12T gear on top is OK.
• I turned the geartrain with the two 8T gears from horizontal to vertical, because otherwise the 16T gear had a collision with the engine

I will post a ldr file in the next days...

Here are some more fotos: https://bricksafe.com/pages/jb70/42083-pimp-up-my-bugatti/pics/gearbox#

[Didumos69]

@jb70, what? I thought you were only going to figure out the gearblock, but you actually tried to fit in my entire gearbox idea. That's really cool! I do think this will still give a ratio difference between reverse and 1st gear. I also thought of a way to brace the upper 8t gear better. I'll post a render later tonight.

I really appreciate your effort to really understand a mod and try to fit it in as good as possible. You even seem to think about how it fits in the build process.?

Edited June 14, 2018 by Didumos69

[jb70]

@Didumos69, i tested the gear sequence in my MOD today.

My sequence is 5-8, 1-4. So switching the blocking mechanism from back to front did not have any effect on the sequence as I supposed first.

Now we need to find a solution to reverse the high/low gearbox without having a 20t gear on top or to reverse the 1-4 gearbox. What do you think?

[jb70]

Replacing 2 knob gears by 3 8t gears would also help to get the right sequence 1-8. It's more difficult to align, but it works:

By the way: There is a nice place to attach an M-motor at the back of the diff to test the gearbox. You only need to replace the blue 20t gear by a normal one.

 

[Didumos69]

2 hours ago, jb70 said:

Now we need to find a solution to reverse the high/low gearbox without having a 20t gear on top or to reverse the 1-4 gearbox. What do you think?

Yes, moving the gearblock does not make a difference, I should have known.

Reversing the 1-4 gearbox can be done by swapping the 16t-20t mesh at the backside, but that would give a much higher input/output ratio of the complete gearbox. The engine would need to be geared down, but that will also affect reverse.

The low-high gearbox can be reversed  by moving one of the red clutch gears to the front and by rotating the wave selector by 90 degree, but that would require the gearblock to move to another spot. Also, reversing the low-high gearbox would require the shift direction of the center shift axle to be the opposite from the original. But that could in turn be resolved by mirroring the entire gearbox from left to right.

I can't make renders right now. I'll do that tomorrow.

It's of course also an option to reinstall the original gearbox and only add the gearblock.

Edited June 14, 2018 by Didumos69

[Erik Leppen]

2 hours ago, jb70 said:

Now we need to find a solution to reverse the high/low gearbox without having a 20t gear on top or to reverse the 1-4 gearbox. What do you think?

Wouldn't you achieve this simply by rotating the orange gear selector 180 degrees? That should swap 1-4 with 5-8, right? (Or am I imagining things as too simple now?)

[Didumos69]

25 minutes ago, Erik Leppen said:

Wouldn't you achieve this simply by rotating the orange gear selector 180 degrees? That should swap 1-4 with 5-8, right? (Or am I imagining things as too simple now?)

Sorry for answering. The issue is that the wave selectors of the 4-speed gearbox and the low-high gearbox need to rotate in the same direction for an up-shift.

Now, with only 2 clutch gears in at one end of the low-high gearbox and a gearblock at the other end, the required up-shift direction is from bottom driving ring to right-side driving ring.

The only way to change the direction is either to swap the driving ring ratios, or to use one clutch gear at one end of the low-high gearbox and for the other driving ring a clutch gear at the other end. The first is not an option, because the gears would stick out too much and collide with the engine.

Edited June 14, 2018 by Didumos69

[Didumos69]

17 hours ago, jb70 said:

@Didumos69, i tested the gear sequence in my MOD today.

My sequence is 5-8, 1-4. So switching the blocking mechanism from back to front did not have any effect on the sequence as I supposed first.

Now we need to find a solution to reverse the high/low gearbox without having a 20t gear on top or to reverse the 1-4 gearbox. What do you think?

I managed to reverse the 4-speed gearbox, so it works in the same direction as in the orginal. The update roughly boils down to switching the input and output axles of the 4-speed gearbox. This means there are now 3 red clutch gears at the front of the gearbox, just like in the original. It also has a better overall ratio. The overall input / output ratio is slightly smaller than the original, but that brings 1st gear ratio closer to reverse ratio. In the original build reverse has a much smaller ratio than 1st gear. The slightly smaller overall ratio can be compensated for, by using 2 16t gears for the engine (see renders). You can find an LDR-file here and an LXF-file here. In the digital file and in the renders the gearbox is in 4th gear. If there is no space for the 2x4 liftarm at the back of the gearbox, a 13L liftarm could be installed right above the two 7L liftarms.

Edited June 15, 2018 by Didumos69

[jb70]

10 hours ago, Didumos69 said:

I managed to reverse the 4-speed gearbox, so it works in the same direction as in the orginal. The update roughly boils down to switching the input and output axles of the 4-speed gearbox. This means there are now 3 red clutch gears at the front of the gearbox, just like in the original. It also has a better overall ratio. The overall input / output ratio is slightly smaller than the original, but that brings 1st gear ratio closer to reverse ratio. In the original build reverse has a much smaller ratio than 1st gear. The slightly smaller overall ratio can be compensated for, by using 2 16t gears for the engine (see renders). You can find an LDR-file here and an LXF-file here. In the digital file and in the renders the gearbox is in 4th gear. If there is no space for the 2x4 liftarm at the back of the gearbox, a 13L liftarm could be installed right above the two 7L liftarms.

Very good work, @Didumos69!

But, unfortunatly there is again a collision: The 24t gear collides with the bottom of the chassis. In the original solution from TLG the 24t gear was mounted two studs further to the back. There is a hole in the chassis, so the 24t gear may run without collision. So I did the same with your solution: moving back the 24t gear while keeping all the gear sequences as you suggested:

More Pics here: https://bricksafe.com/pages/jb70/42083-pimp-up-my-bugatti/pics/gearbox-v2

I think we now come close to a perfect MOD of the gearbox!

[chox]

3 hours ago, jb70 said:

Très bon travail,  @ Didumos69 !

Mais, malheureusement il y a encore une collision: Le train 24t entre en collision avec le fond du châssis. Dans la solution originale de TLG la roue 24t a été montée en outre deux ergots à l'arrière. Il y a un trou dans le châssis, de sorte que le pignon 24T peut fonctionner sans collision. Donc, je l'ai fait la même chose avec votre solution: déplacer l'engrenage arrière 24t tout en gardant toutes les séquences de vitesse comme vous le suggérez:

Plus de photos ici:  https://bricksafe.com/pages/jb70/42083-pimp-up-my-bugatti/pics/gearbox-v2

Je pense que nous arrivons maintenant près d'un MOD parfait de la boîte de vitesses!

It still remains to make from an 8-speed gearbox to a 7-speed gearbox as for the real Chiron.

[Kumbbl]

@chox: May i ask you preventing your browser from translating all quotes to french? This is an english forum

[WvG_853]

21 minutes ago, Kumbbl said:

@chox: May i ask you preventing your browser from translating all quotes to french? This is an english forum

I am actually impressed by the quality of the translation! What is the issue? The answers are in English ...

[Kumbbl]

Just now, WvG_853 said:

I am actually impressed by the quality of the translation! What is the issue? The answers are in English ...

well, in this case i admit i does not really matter - but imagine a quote where the original post is far away then you have only a quote in french and the english answer but you can maybe not understand the correlation between the quote and the answer... anyway: IMHO all contributions incl. quotes should be in english here - but i'm not a Mod so just take this as a friendly hint and nothing else ;-)

[Jim]

Just now, WvG_853 said:

I am actually impressed by the quality of the translation! What is the issue? The answers are in English ...

There is no real issue, but since this is an English forum, let’s stick to that.