Smallest 4 speed 4wd gearbox?

[Attika]

Hi Fellas,

I've built a gearbox for 4x4 vehicles and it is rather space efficient. Hope you find it usefull. 

As usual, I'm being lazy and copy-paste the video description as it has all the basic info. Please feel free to ask, judge, or comment and I try to give my best in the reply 

 

 

It is rather small, I'd love to claim that it is the smallest of it's kind. (but I'm not sure, so I don't say that yet.) Help me find out.

Dimensions:

L: 7 studs

W: 9 studs

H: 5 studs

Comes with the usual gear ratios:
1st gear 8/24 x 16/24
2nd gear 8/24 x 16/16
3rd gear 16/24
4th gear 16/16

The selector lever required some attention as the upper axles are 5 stud apart. I've been using some rare parts there:

-Technic Ball Joint with Through Axle Hole

http://www.bricklink.com/v2/catalog/catalogitem.page?P=53585#T=C

-Bar 4L (Lightsaber Blade / Wand)

http://www.bricklink.com/v2/catalog/catalogitem.page?P=30374&idColor=16#T=C&C=16

 

However this lever mechanism can do the shifting quite well, it still not "stupidproof" and need some attention while changing gears.

The frame (housing)

First. It is made so colorfull to help you dear watcher separate the parts on the video.

For motorized version I recommend to rebuild the housing using studded technic parts.

Input/Output

Outputs are self-explanatory, two red axle ends sticking out from the differential.

The input in the other hand is the axle with the 8tooth gear on the front. It is offset by 2 studs, but using a pair of gears it can be transfered to the center too. Whats more, it can be done on the front as well as on the rear side.

 

Thank for your attention

Edited January 22, 2017 by Attika

[Victor Imaginator]

Cool and tiny) Sad, but i don't have that old differential. Like non standart parts usage)

[doug72]

Nice compact gearbox - well done.
I like compact gear mecanisms and the challange when building them.
Video instructions are very clear and I will certainly be building this.
The Technic ball with through axle hole is readilly available on line, just checked Brickowl at £0.03 each

An alternative would be to use the normal red change over lever with it sliding back and forth between driving rings via a gate.

Edited January 22, 2017 by Doug72

[Attika]

2 hours ago, Doug72 said:

An alternative would be to use the normal red change over lever with it sliding back and forth beteeen driving rings via a gate.

Thank you for the nice words. The method you mentioned is clearly right, but consuming too much space if it is used in a small scale model. That's why I went this way. The model I built this for is only 11 studs wide inside.

[Leonardo da Bricki]

This great! I was planning to make a small-scale Jeep, with a 2 speed transmission, but I may just use this instead. Thanks for providing instructions! What vehicle is this excellent gearbox going to go on?

[Didumos69]

I like 4x4 gearboxes that take advantage of both outer gears of the center diff. I'm not a big fan of all these half stud offsets, but it certainly is compact. Nice work!

[Attika]

5 hours ago, Leonardo da Bricki said:

This great! I was planning to make a small-scale Jeep, with a 2 speed transmission, but I may just use this instead. Thanks for providing instructions! What vehicle is this excellent gearbox going to go on?

Thanks. It's gonna be a small scale pickup truck.

 

49 minutes ago, Didumos69 said:

I like 4x4 gearboxes that take advantage of both outer gears of the center diff. I'm not a big fan of all these half stud offsets, but it certainly is compact. Nice work!

I share your feeling about half studs, but it is a trade off on the size market... By the way I'm glad you remembered and the way you treat the 8880 evo the other day. Thanks. But back to the gearbox: you have any idea how turn this one into sequential? The symmetric structure doesn't help, does it?

[syclone]

Will build this later today, very compact build! 

[Didumos69]

10 hours ago, Attika said:

But back to the gearbox: you have any idea how turn this one into sequential? The symmetric structure doesn't help, does it?

You're gearbox layout is not much different from the one I developed for my Rugged Supercar - yours is more compact of course - so you could have a look at the sequential shifter I use. It will probably take too much space, but it could be a source of inspiration, see video link below. And you do need to somehow make sure one clutch operates 1st and 3rd gear and the other 2nd and 4th gear. Here's the LXF-file of the entire chassis, but please note that this is work in progress.

https://youtu.be/mWmSTUbncdM?t=45s

Edited January 23, 2017 by Didumos69

[Attika]

11 hours ago, LXF said:

Will build this later today, very compact build! 

I'd appreciate a feedback. Thank you in advance. 

 

8 hours ago, Didumos69 said:

You're gearbox layout is not much different from the one I developed for my Rugged Supercar - yours is more compact of course - so you could have a look at the sequential shifter I use. It will probably take too much space, but it could be a source of inspiration, see video link below. And you do need to somehow make sure one clutch operates 1st and 3rd gear and the other 2nd and 4th gear. Here's the LXF-file of the entire chassis, but please note that this is work in progress.

http://bricksafe.com/files/Didumos/fast-animal/Fast animal - drt I.lxf.png/960x270.jpg

https://youtu.be/mWmSTUbncdM?t=45s

I quickly built yours by the video. If I can hold and roll it around gives me a better feeling and understanding. The main problem I had is to change mine to the 1-3, 2-4 sequence. Now having both on my desk helped me understand something rather funny. Instead of revealing it now I give you a housework: How would you turn yours into manual (1-2, 3-4 sequence)? Beside that I have to confess, I didn't really follow anything lately, but having a deeper look now this supercar is impressing.

 

Edited January 23, 2017 by Milan
Removed quoted image from previous post.

[Meatman]

I like this concept. But the one issue I can see is those connectors on the axle. I've built some gearboxes from some very talented builders who used the connector on the axle technique and there was always some fine tuning that needed to be applied. Also not real keen on that red clutch gear on just that pin. Seems like it would be a little wobbly since that pin has play in it and without any support on the other side which could cause some friction.

Edited January 23, 2017 by Meatman

[Lox Lego]

My first thought was isn't it too wide? I don't think you could place seats on either side of this gearbox. Other than that it looks interesting.

[Attika]

1 hour ago, Meatman said:

I like this concept. But the one issue I can see is those connectors on the axle. I've built some gearboxes from some very talented builders who used the connector on the axle technique and there was always some fine tuning that needed to be applied. Also not real keen on that red clutch gear on just that pin. Seems like it would be a little wobbly since that pin has play in it and without any support on the other side which could cause some friction.

So, one issue the connectors and the gear on pin.  

When I buld a car the chassis itself designed to be the frame of the gearbox, so put it this way this is a self sustaining frame for demonstration purposes. In this form it is capable to be built in a 1:10 scale non motorised model and perform without problem. If I was to put an XL motor on it and pull the furniture around I build a frame out of studded technic parts. (in fact I did  ) For me a gearbox means the layout of the gears, frame is like outfit: up to the occasion. Gear on the pin is the same thing.

1 hour ago, Lox Lego said:

My first thought was isn't it too wide? I don't think you could place seats on either side of this gearbox. Other than that it looks interesting.

Price of the short length is some width no dubt, but the seats will be in the level of the ball joint of the lever, so the seats ar above the gears. It is a pickup truck, so kinda reasonable. And of course please look at the frame as an interchangeable thing.

[Meatman]

So there is no play in that red clutch gear on the pin? I just know that when a gear wobbles, it creates friction.

[Attika]

3 minutes ago, Meatman said:

So there is no play in that red clutch gear on the pin? I just know that when a gear wobbles, it creates friction.

In the non motorized model there isn't any sign of that. In first gear, when the dummie engine's rev is the highest it is runing it smoothly.

[Didumos69]

18 hours ago, Attika said:

Now having both on my desk helped me understand something rather funny. Instead of revealing it now I give you a housework: How would you turn yours into manual (1-2, 3-4 sequence)? Beside that I have to confess, I didn't really follow anything lately, but having a deeper look now this supercar is impressing.

Thanks!

To make mine manual I would move the axles with the 8t gears that mesh with the 24t side of the diff half a stud outwards and replace the 8t gears with 16t gears. And I would replace the 20-12 mesh in front of the clutches with a 24-8 mesh. That way it would more or less boil down to your layout. We've build two gearboxes independently that are each others direct shifting / sequential shifting counterparts . I guess that's the funny finding you are referring to?

I would in my case hold on to the centered input axle though.

Edited January 24, 2017 by Didumos69

[Attika]

7 hours ago, Didumos69 said:

We've build two gearboxes independently that are each others direct shifting / sequential shifting counterparts . I guess that's the funny finding you are referring to?

Yep, that is what I wanted you to discover. I think this way was more entertaining than if I just told you...

7 hours ago, Didumos69 said:

I would in my case hold on to the centered input axle though.

For that you need two "layers" of gears just as it is done in your version. My goal was to minimize the size. Beside that the chassis I built it for has the "flexibility" to handle this odd position as the dummie engine is connected to the gearbox by a pair of uni joints. Later maybe in another built if it requires I'll change that front part. 

[Didumos69]

19 hours ago, Attika said:

Yep, that is what I wanted you to discover. I think this way was more entertaining than if I just told you...

It is indeed the kind of puzzle that I like to break my head on , The more general observation is that the main gear layout difference between the two variants is that the sequential variant needs a small gear reduction between the clutches and a high(er) reduction between both ends of the diff and the manual variant needs a high gear reduction between the clutches and a small(er) reduction between both ends of the diff.

19 hours ago, Attika said:

For that you need two "layers" of gears just as it is done in your version. My goal was to minimize the size. Beside that the chassis I built it for has the "flexibility" to handle this odd position as the dummie engine is connected to the gearbox by a pair of uni joints. Later maybe in another built if it requires I'll change that front part. 

I understand. I didn't mean you should change your setup. I meant to say that in my case it doesn't need to be that compact. I also use the longer type of clutches which adds another stud. But what you could do to slightly improve the play in the red clutch gear in the front section would be to replace it with a normal 16t gear attached to a pin with axle (without friction ridges). Now both ends of your normal pin (without friction ridges) add to the wobbliness.

Edited January 25, 2017 by Didumos69

[Attika]

5 hours ago, Didumos69 said:

But what you could do to slightly improve the play in the red clutch gear in the front section would be to replace it with a normal 16t gear attached to a pin with axle (without friction ridges). Now both ends of your normal pin (without friction ridges) add to the wobbliness.

We have been here before (or above). In this setup it is easy to spectate, not covered by beams yet performs well in a non motorized model. The same reason it is in all the colors of a parrott: Demonstrating on video. I made a terrible picture quickly to show it how it is built in my case.  The 16t gear is supported from both side. (Technically that axle drives the dummie engine). As I was writing above, if it is built in there must be a chassis anyway. 

 

Leave my red clutch gear alone 

Edited January 25, 2017 by Attika

[FLOGO]

This is my contribution. I hope you find it useful,

Its not fully(!) studless but smaller than small:

If anyone could convert this to studless ill be very happy!

 

01 by LOGOOGOL, auf Flickr

08 by LOGOOGOL, auf Flickr

06 by LOGOOGOL, auf Flickr

 

[Attika]

3 hours ago, FLOGO said:

This is my contribution. I hope you find it useful,

Its not fully(!) studless but smaller than small:

If anyone could convert this to studless ill be very happy!

It is small, hats off. Converting into studless seems tricky . 1/3 stud!  ,  I'll thinker on it. Worth it.