Turntable ideas

[Zerobricks]

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.

[Milan]

Really nice idea with planetary gearbox!!!

[CP5670]

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, 2010 by CP5670

[DLuders]

@ 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, 2010 by dluders

[CP5670]

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.

[Sternford]

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

[Jurgen Krooshoop]

Oh man, your technical ideas are so good.

[Zerobricks]

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, 2010 by Zblj

[darksheep]

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

[Zerobricks]

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

[jantjeuh]

Just found this thread, some great ideas in here

[axd010 - MaxBrick]

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

[jantjeuh]

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, 2010 by jantjeuh

[Sam42]

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

[Sam42]

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, 2011 by Sam42

[Aqualize]

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?

[Sam42]

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..

[Ayumi]

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

[Sam42]

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, 2011 by Sam42

[Tobbe Arnesson]

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

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

[Sam42]

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

fixed it now! well spotted Tobbe!