The Ultimate Wheel

[Junpei]

Today I figured out something that may revolutionize Lego building:

The ultimate wheel. I always tried to find a way to create planetary reduction with the Power Miners wheel, but due to its unusual shape and size, they all failed. But today I thought of an idea for this part- (quote from efferman) How do you get planetary gear reduction with a pivot close to the center of the wheel? Ditch the wheel!

Here are some specs and pictures:

A 6x6 disc fits perfectly to hide the ugly spikes:

A 3-stud rim offset:

The CV joint hub's pivot is inside the wheel, more easily seen here:

If you use 8448 hubs, the pivot is in the dead center of the wheels.

And lastly, the thing you've all been wating for...

PLANETARY GEAR REDUCTION!!

You can make a hub with 5 gears out of connectors, but I was too lazy The ratio is even higher than the turntable planetary gears used in Zblj's Tatra, and even better yet, bigger gears means less backlash, more strength and less friction!

[MrNumbskull13]

Cool! I have those wheels and tires, I think I'll try this one day. :)

[Lipko]

Does it roll smoothly? I mean how evenly the tire is stretched on the miner wheel part?

[Junpei]

The tyre keeps its original form factor almost perfectly, maybe just stretched a millimeter on one side. No fluctuations in diameter though.

I can tell the ratio is lower than a turntable ring gear and an 8t gear (3:1), but does anyone know how many teeth the Power Miners wheel's ring gear is? I'm not sure of the exact ratio.

Edited November 17, 2013 by TwentyLeggedHen

[Zerobricks]

The tyre keeps its original form factor almost perfectly, maybe just stretched a millimeter on one side. No fluctuations in diameter though.

I can tell the ratio is lower than a turntable ring gear and an 8t gear (3:1), but does anyone know how many teeth the Power Miners wheel's ring gear is? I'm not sure of the exact ratio.

16x3 tooth :) thats 48 and you get 1:3 gear taio. Good work need to get some of those power miners parts.

[allanp]

The power miners ring gear has 48 teeth, equal to the total amount of the 3 16t gears. The method of reduction described above will give you a 3:1 ratio. To get a 4:1 ratio you need to have the ring gear stationary and attach the wheel to the rotating 5L beam. EDIT Zblj beat me to it!

Edited November 17, 2013 by allanp

[Junpei]

Oh, I guess I could have figured that out myself, I didn't think about that. Thanks.

You could also use an 8t gear and 20t gear for a 1:5.4 (?) ratio.

As posted on Mark J. E. Bellis's website:

These are the 3 hubs you can use for the power miners wheel.

[That_LEGO_Guy]

I've been using this method for portal axles with 8466 tyres for almost a year, they perform great, never slipped even pulling 15+kg or vertical wall climb , not too sure how well compared to the portal frames as I have none. I never had something to post it in as nothing got done/worked(gearbox suspension and most of my PF stuff stopped working) and yes the speed is reduced 3:1 with the 16t(check my Flicr in set Unimog! for pic, can't get it to link )

[nicjasno]

Does this fit into the unimog wheels?

[Doc_Brown]

Today I figured out something that may revolutionize Lego building:

You can make a hub with 5 gears out of connectors, but I was too lazy The ratio is even higher than the turntable planetary gears used in Zblj's Tatra, and even better yet, bigger gears means less backlash, more strength and less friction!

Great discovery! :D

How do you get it like this? I tired with mine and you must have to stretch it a lot!

Edited November 17, 2013 by Doc_Brown

[jorgeopesi]

Great idea and 100% Lego :thumbup: .

[Junpei]

Does this fit into the unimog wheels?

Sorry, I don't know, I don't have any of the Unimog tyres myself.

Great discovery! :D

How do you get it like this? I tired with mine and you must have to stretch it a lot!

Yes, it does have to stretch a lot. It took me about 5 minutes and my fingers were quite sore after that.

Great idea and 100% Lego :thumbup: .

Thanks!

Actually, I think it will probably fit unimog rims if it can fit power pullers on it. Although I think it might perform not as well because the unimog rims are flat; balloon tyres allow for some fluctuations in diameter without affecting performance.

[DrJB]

That is neat ... I have done something similar to replicate the final planetary reduction in wheel hubs of large machinery. There, the internal gear (power miner here) is typically attached to the chassis/axle. An LXF of such design can be found below.

http://www.brickshel...ry.cgi?f=536390

http://www.brickshelf.com/gallery/djamil/Planetary-Gear/planet0.jpg

Edited November 18, 2013 by DrJB

[MrNumbskull13]

Would you say the pivot point with this is better than portal hubs?

[skppo]

That is neat ... I have done something similar to replicate the final planetary reduction in wheel hubs of large machinery. There, the internal gear (power miner here) is typically attached to the chassis/axle. An LXF of such design can be found below.

http://www.brickshel...ry.cgi?f=536390

http://www.brickshelf.com/gallery/djamil/Planetary-Gear/planet2.jpg

I don't see anyhing keeping the planetary assembly from falling out.

Edited November 18, 2013 by skppo

[Junpei]

Would you say the pivot point with this is better than portal hubs?

Yes, it's much better, about 2-3 studs inboard.

[1gor]

Yes, it's much better, about 2-3 studs inboard.

do you have image with portal axle hub? I'm looking for 2 years how to put portal axle hub inside wheel to make proper mbtrac, but so far nothing that is strong enough like portal axle housing.

.

[DrJB]

I don't see anyhing keeping the planetary assembly from falling out.

You're absolutely correct. That LXF was done to illustrate how in-wheel final reductions work. Because the Y-liftarm comes with an AXLE hole, it is difficult to prevent the whole assembly from sliding off. Had the Y-liftarm been with a smooth hole, there would have been options. Now, to prevent the assembly to 'fall off' (as you say it), you need to restrain the wheel from the opposite side (pic below). This also gives better support than the single axle from the vehicle/chassis end.

http://www.brickshelf.com/gallery/djamil/Planetary-Gear/planet4.jpg

[Junpei]

do you have image with portal axle hub? I'm looking for 2 years how to put portal axle hub inside wheel to make proper mbtrac, but so far nothing that is strong enough like portal axle housing.

.

Sorry, I don't have any of them, I used a picture from efferman to compare:

Anything on portal hubs tends to have a pretty bad turning radius, I can tell without looking that it's better.

[1gor]

Sorry, I don't have any of them, I used a picture from efferman to compare:

Anything on portal hubs tends to have a pretty bad turning radius, I can tell without looking that it's better.

Thank you,

that is what I thought. Portal Axle Hub by Effe with additional modifications is only solution for me to fit inside wheel futuristic.