Gearboxes With New Orange Selector & 20z Clutch Gear

[Jack Bloomer]

Are half stud offsets in gearboxes considered “illegal” building techniques because I noticed that TLG never uses them in their speed or function transmissions. 

[allanp]

What do you mean by half stud offset? The kind used in 8448 or the kind used in 8265?

[Jack Bloomer]

Like in gearboxes above on this forum

[BusterHaus]

@Jack Bloomer TLG has a lot of different (often competing) targets to reach when designing a set, including minimal part count and durability. Half stud offsets do not stress parts, so they are most likely legal, but they increase complexity and part count. AFOLS are not subject to the same targets, so we are free to build in ways that will never be used by TLG.

That being said, a portion of us stick to not stressing parts and only having legal connection, or avoiding illegal ones as much as possible possible. @Didumos69 designs his stuff this way, so I wouldn't worry about half stud offsets in his hands. 

[allanp]

I thinks it's legal but might be tricky for the target age group to understand and build and also can be tricky to properly brace from a structural standpoint. 

[Didumos69]

For two gears to mesh perfectly, you need 16 teeth alltogether for each stud they span (center to center). So with 2 8t gears you can span 1 stud (8t + 8t = 16t), with 2 16t gears you can span 2 studs (16t + 16t = 32t) and also with a 12t-20t mesh you can span 2 studs (12t + 20t = 32t) and with a 8t-24t mesh you can span 2 studs (8t + 24t = 32t).

So, to span 1.5 stud, you need 24 teeth: a 12t-12t mesh or a 8t-16t mesh. For 2.5 stud you need 40 teeth: a 20t-20t mesh or a 16t-24t mesh. In the example below all gear meshes are perfect. Only the distance between the rotary catch and the driving rings is not perfect (it's 2.12L, where in the ideal situation it should be 2L).

A non-perfect distance that is often used, is the distance spanned by 2 studs in one dimension and 1 stud in the other dimension. That would require 16 * sqrt(1^2 + 2^2) ≈ 35.78 teeth, which comes close to 36 teeth, which can be obtained with a 16t-20t mesh or a 12t-24t mesh. The 16t-20t mesh is used in the Bugatti gearbox. Finally, a mesh I would not consider as acceptable is a 20t-24t mesh used to span 2 studs in one dimension and 2 studs in the other dimension. The distance would require 16 * sqrt(2^2 + 2^2) ≈ 45.25 teeth, more than a tooth more than the 20t-24t mesh. However, also this mesh is used in the Bugatti, in the DNR to be precise.

Edited June 21, 2018 by Didumos69

[Jack Bloomer]

@BusterHaus thanks for the explanation 

[Jack Bloomer]

@Didumos69 Could you make a rendering of the Bugatti Gearbox 

NVM I found it on other forum the 42083 mods one

Edited June 22, 2018 by Jack Bloomer

[Seasider]

Not having tried to construct my own gearbox, well at least not one of any worth, how easy would it be to create a multiple fwd and single reverse gearbox but make it long in length instead of compressed in length but "boxy" - is this at all possible ? this could then mean a small "transmission tunnel"

[Meatman]

New 180 limiter idea from crowkillers

 

[Didumos69]

On 5/30/2018 at 6:10 PM, Didumos69 said:

Great idea, I was waiting for this! Here we go...

I tried making a compact sequential 4-speed gearbox layout and so far this is the most simple solution I could come up with. It's still not that easy, because to take full advantage of the new orange selector, the driving rings cannot be placed on opposite sides of a single gear selector.

To take full advantage of the new 20t clutch gears, the gear ratio between the two driving rings needs to be closer to 1:1 than the 20:12 ratio made by the new clutch gears. In this case I used 16:20. Ratios are (in foreground to background order): 4:5, 1:1, 4:3, 5:3.

Finally recieved the parts to build this.

[Didumos69]

On 6/12/2018 at 9:08 AM, Didumos69 said:

+1.

I have been playing with the new wave selector a bit more (in LDD) and tried to figure out a 4-speed gearbox that meets some of my criteria:

• To minimize friction, I don't want clutch gears to be involved in tranferring drive. When one clutch gear is engaged, all the others should be plain idler gears.
• To allow for easy integration with a fake engine and with front or rear axles, I want to have a symmetrical setup with he input axle, output axle and the control axle nicely centered.

One of the things about the new wave selector I'm not so happy with, is that it is hard to make a symmetriacal setup. They are easy to use in a setup with one driving ring to the side of the wave selector and one underneath or above the wave selector. If you put the wave selector right inbetween two driving rings, you can't make a 4-speed sequential gearbox, because either both driving rings will be engaged or none.

By making use of some half stud offsets, I think I found something that should work. Ratios are 0.83, 1.67, 2 and 4.

And this one:

[Didumos69]

On 6/26/2018 at 2:45 PM, Seasider said:

Not having tried to construct my own gearbox, well at least not one of any worth, how easy would it be to create a multiple fwd and single reverse gearbox but make it long in length instead of compressed in length but "boxy" - is this at all possible ? this could then mean a small "transmission tunnel"

I like the idea of a transmission tunnel. I tried setting something up for a plain 8-speed gearbox, no reverse. Green is input, black is control and red is output. The nice thing about this setup is that no drive is passed via clutch gears. All clutch gears are idle, except the two that are engaged. I also reserved space for a 8<->1 gearblock and for 90 degree limiters on both the shift axles. Will try this this weekend.

LXF-file here.

Edited June 29, 2018 by Didumos69

[Seasider]

Thanks @Didumos69, good to see an expert having a go at my suggestion. Looking forward to hearing if it works or not.

 

[1gor]

7 hours ago, Seasider said:

Thanks @Didumos69, good to see an expert having a go at my suggestion. Looking forward to hearing if it works or not.

 

Yes now @Didumos69 should earn new title Bugatti perfekcionist title ?

[allanp]

So I finally picked up a Chiron today and played with the new selector piece a bit before building the model and can confirm a couple things.

1) We know that when used with a 90 degree stepper it works fine. But it WILL also work with a 60 degree stepper. So the steps are engaged>disengaged>disengaged>engaged>disengaged>disengaged. I tested this just using a pulley wheel and rotating the shaft with the pulley wheel one hole at a time and it works. YAY! However there is a caveat which I'll mention in point 3.

2) The drive rings MUST be mounted on the newer style of 3M axle connector released with the Porsche. The older type that makes the drive rings click into place are not suitable as the wave selector piece struggles A LOT to engage/disengage gears when using it. I felt like I might damage something.

3) When everything is setup as they are in the Chiron with the 90 degree stepper being used and two drive rings controlled by the same wave selector one gear engages at about the same moment as another disengages. So in a perfect world there's no possibility of 2 gears ever being selected at once at any given time. However in our imperfect world where slop has to be taken into account there is that small possibility of 2 gears being selected at once during one brief and tiny moment during shifts, but not before or after shifting. This will most likely only be an issue for motorised models that shift gears while under power. This issue may be more prevalent when using 60 degree steppers but again, this is only during that brief moment during a shift and only while under power.

[SpaceJoey86]

3 hours ago, allanp said:

2) The drive rings MUST be mounted on the newer style of 3M axle connector released with the Porsche.

How about the 2M axle connectors?

[allanp]

I assume you mean with the 2M axle connectors (both with and without ridges) combined with the 2M drive rings? Unfortunately the wave selector is buried inside a half built Chiron so won't be able to test that until I dismantle it.

[bekesizoltan]

On 6/29/2018 at 10:26 AM, Didumos69 said:

I like the idea of a transmission tunnel. I tried setting something up for a plain 8-speed gearbox, no reverse. Green is input, black is control and red is output. The nice thing about this setup is that no drive is passed via clutch gears. All clutch gears are idle, except the two that are engaged. I also reserved space for a 8<->1 gearblock and for 90 degree limiters on both the shift axles. Will try this this weekend.

LXF-file here.

This is totally mental, there are lot of mocs that has no big place to have a complex gearbox, but your design would solve those issues, basically it could replace the cardanshaft through the car from front to back.
Would it be hard to instead of having 1 to 8 have a Reverse + 1 to 7; or Reverse, Neutral and 1 to 6? 

[Didumos69]

8 hours ago, bekesizoltan said:

This is totally mental, there are lot of mocs that has no big place to have a complex gearbox, but your design would solve those issues, basically it could replace the cardanshaft through the car from front to back.
Would it be hard to instead of having 1 to 8 have a Reverse + 1 to 7; or Reverse, Neutral and 1 to 6? 

I was able to make it 2 studs shorter and it actually works very well. Making it 7+R or 6+N+R won't be simple because it's actually two gearboxes, a 4-speed and a 2-speed. Reversing one speed in the 4-speed gearbox will affect 2 speeds of the whole gearbox. It would need a separate DNR switch I think.

Edited July 3, 2018 by Didumos69

[TeamThrifty]

On 7/1/2018 at 7:28 PM, SpaceJoey86 said:

How about the 2M axle connectors?

i've currently got one in use in a diff-lock situation using old red 2L driving rings on a smooth 2L axle connector - works perfectly.

Worth noting though, that the orange selector needs to be 0.5l offset when using old 2L rings, but as lego thoughtfully provide 0.5L bushes, its drama free!! And it does make diff-lock a lot neater.

And it can't 'unlock' as its effectively trying to drive a worm gear backwards, which as we all know, it can't... so difflock stays locked even when torqued up.

 

[Didumos69]

48 minutes ago, TeamThrifty said:

i've currently got one in use in a diff-lock situation using old red 2L driving rings on a smooth 2L axle connector - works perfectly.

Worth noting though, that the orange selector needs to be 0.5l offset when using old 2L rings, but as lego thoughtfully provide 0.5L bushes, its drama free!! And it does make diff-lock a lot neater.

And it can't 'unlock' as its effectively trying to drive a worm gear backwards, which as we all know, it can't... so difflock stays locked even when torqued up.

Good to know . Do the old 2L rings also engage properly with the new 20t clutch gears?

[TeamThrifty]

Just now, Didumos69 said:

Do the old 2L rings also engage properly with the new 20t clutch gears?

No, they're the same as the newer red clutch gear. They won't engage with the old red driving ring for the same reason - the central 'collar' thats a larger diameter on the new gears won't insert into the old driving ring. the new 4L driving ring has a larger diameter hole.. if that makes sense?

[Didumos69]

1 minute ago, TeamThrifty said:

No, they're the same as the newer red clutch gear. They won't engage with the old red driving ring for the same reason - the central 'collar' thats a larger diameter on the new gears won't insert into the old driving ring. the new 4L driving ring has a larger diameter hole.. if that makes sense?

Thanks! Yes, that makes sense. I knew about the problem with the red clutch gear so it sounds logical. The newer driving ring is 3L btw.

Edited July 3, 2018 by Didumos69

[TeamThrifty]

Update: The new blue clutch gears WILL engage with the old driving ring extenders, so its possible in some situations that they could be retro-fitted.. so red 2L driving ring + old gray extender + blue 20t clutch = OK

1 minute ago, Didumos69 said:

The newer driving ring is 3L btw.

Ha! just looked at what i typed... Doh! must need more coffee... 

Edited July 3, 2018 by TeamThrifty
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