Wheel Building

[quilkin]

The biggest Lego wheels made in one part (as far as I can see) is like this or like this which is 20 studs diameter. But these are a bit limited for, say, tractor wheels.

How can you get bigger wheels? I started by building a wheel like this, for a racing bike

All the parts in this design are stressed in ways TLC wouldn't approve of, but then real bike wheels are designed to be under stress anyway.

After that I wondered about making some wheels for a decent-sized tractor or traction-engine and came up with this

which isn't as elegant or stable (and also has many stressed parts) but is very flexible in design, in that it could easily have a bigger diameter or width.

If you limit the design to non-stressed parts you can do this

but the size has to be either 40 or 42 track links, anything smaller won't bend and anything bigger is too floppy (the 42-link version has 6 spokes each side, separated by 7 links each). And many other lego designers have used these links for wheels or other circular constructions.

I think my favourite is this one

because it's the most elegant.

Any other ideas?

[lisqr]

How about something like this troll battle wheel?

It's not technic, but it's a big wheel nonetheless.

[TechnicJuan]

I am not a big fan of flexing parts to make things fit.

[Ras_Al_Ghul]

i think the key to building large wheels is click hinges

[DLuders]

You can make bigger wheels by using the Lego-compatible aluminum liftarms available from http://www.bricklink.com/storeDetail.asp?p...mp;itemStatus=U . There is a liftarm that has a lockable pivot angle: "... adjustable 6x6 Liftarm can be fixed at any angle from 60 to 300 degrees and locked into position." Theoretically, one can make a wheel as large as one wants because each outer segment can have just a small, incremental "bend" to form a HUGE circle. With aluminum, one doesn't have to worry about overstressing the usual ABS plastic parts.

By the way, the biggest Lego "wheel" is the Hailfire Droid x784 "Technic, Gear, Hailfire Droid Wheel" ( http://www.bricklink.com/catalogItem.asp?P=x784 ).

Edited February 26, 2010 by dluders