So, here is my first idea, a turntable differential. I built a simillar one for one of nicjasno's models.

I used knob gears, which cannot slip and a 7 stud lego smooth axle. This give the diff a bit of friction when cornering, but its not really noticable with big models.

I also built a model in LDD:

http://www.brickshelf.com/gallery/zblj/Ideas/heavy_diff.lxf

The next idea is a alternative solution to power up big models.

Using four 8 tooth gears inside the tunrtable and a fith one to power it, i made a planetary gearbox with 1:3 ratio inside the power puller wheel. Also the turntable provides aditional rigidity. You can now use any normal differential to power up this wheel.

The inner wheels:

Top assembly is quite complex, yet sturdy:

Because of the way two 8 tooth gears are attached inside, the assemby seems to work better one way, but its nothing too problematic:

And the LDD file:

http://www.brickshelf.com/gallery/zblj/Ideas/planet.lxf

I will definatelly use this idea for any big truck.

Really nice idea with planetary gearbox!!!

Some great ideas here. This looks more robust than most of the limited-slip differentials I've seen before, which typically used rubber bands.

Another solution to the issue of slipping wheels is a torsen differential like this one. If one wheel goes off the ground, this setup allows the idle wheel to transfer power to the grounded one.

I like your planetary gearing setup too. Although I do wish TLG would give us a larger ring gear for doing this. The ring in the turntables is too small to do a lot with.

Edited July 18, 201014 yr by CP5670

@ Zblj: I downloaded your LDD .lxf file and could see that the Turntable Differential is extremely strong. Mating a planetary gear setup to the turntable is a great idea. This TechnicBRICKS Blogspot post talked about planetary gears in the Power Miners-type wheels (parts 64711 + 64712 + 64713 ):

Edited July 18, 201014 yr by dluders

Very interesting. I actually had no idea those Power Miners wheels contained ring gears inside. The shape is a little clunky due to the depth of the wheels, but they're still a big step forward and would allow for a lot of new possibilities with Technic. I'll need to get some of those wheels off Bricklink.

That planetary gearbox is really cool. I only have one of the old turntables, but I threw something together that works. If only I had something to use it for though

Oh man, your technical ideas are so good.

Thanks guys!

I also redo the planetary gear idea, and made it stronger and stiffer. I also fixed the problem that allowed two gears to move and i managed to add another point for the drive axle to go through for better bracing.

I couldnt done it so well without the L shaped gray-bluish connectors.

Updated LDL model:

http://www.brickshelf.com/gallery/zblj/Ideas/planet.lxf

Edited July 19, 201014 yr by Zblj

This might solve a problem i am having with a moc i am building now do you mind if i use your idea ?

You think i post ideas, so noone can use them? Of course use it, and tell me how it works for you

Just found this thread, some great ideas in here

Great ideas Zblj. My torsen differential I built with an half turntable :

Looks nice, but a big big Here are some ideas for smaller Torsen differentials.

Anyone ever used one in a MOC btw?

Edited November 11, 201014 yr by jantjeuh

oooh nice work.. i've been playing around with turntables for portal hubs...

oooh nice work.. i've been playing around with turntables for portal hubs...

further to this here are a few pics of my planetary reduction hub developments

my turntable based planetary reduction hub, driven by the black cross axle in the centre, steering centre would be 1 stud out from the holes on the turntable using a 3l u-joint.

Gives a 1:3 reduction.

Part heavy though, uses 2 turntables (outer 1 split) per hub

(sorry about the poor part legibility due to the black elements used and poor photography)

(EDIT- i don't know whats going on with that the embedding on that second pic?)

(2nd EDIT missing [ spotted and added!)

Edited January 24, 201114 yr by Sam42

Ohh this is very interesting. I hadn't thought of using planetary gear reduction inside the turntables. I definitely need to try this out. Luckily I have a bricklink order already on the way with more turntables :) I've started building a "trail vehicle" (can't call it a truck because it won't look like one) which I have used turntables bolted to the wheels but placed a 16 teeth gear outside to power it. The focus on the vehicle is extreme ground clearance.

I see you have split a turntable, does it brake them or can they be put together and work as new?

I see you have split a turntable, does it brake them or can they be put together and work as new?

they split without breaking relatively easily, and if they're any weaker once reassembled i haven't noticed..

Lomero(LUGPol.pl member) had a similar idea, but without reduction.

Haha! it was lomero's wheels that inspired my own!

Any clues on what's going on inside those wheels of lomero's Ayumi?

Edited January 23, 201114 yr by Sam42

(EDIT- i don't know whats going on with that the embedding on that second pic?)

There's a [ missing before the "url="-part.

There's a [ missing before the "url="-part.

fixed it now! well spotted Tobbe!