Type "Püttmann 1"

Note the clever use of the tiny "teeth" on the rubber tires instead of bevel gears. Wheel 7 is just an idler, and the wheel base depends purely on the ratio between wheel 11 and the differential "barrel" if built as shown in the building instructions.

As usual, the dimensioning equations:
 

(a:)	rot3 + rot5 - 2 * rot4 = 0
(b:)	n1 * rot1 + n2 * rot2 = 0
(c:)	n6 * rot6 = n8 * rot8
(d:)	n9 * rot9 + n10 * rot10 = 0
(e:)	n4 * rot4 + n11 * rot11 = 0

 The remaining constraints:

(f:)	rot8 = rot9
(g:)	rot2 = rot3
(h:)	rot6 = rot5

Composition

(g,b=>)	rot3 =  - (n1 / n2) * rot1
(c,f,h=>)	rot5 =  (n8 / n6) * (n10 / n9) * rot10
(e,a=>i:)	rot11 = (n4 / n11) * (1/2) * ( (n1 / n2) * rot1 - (n8 / n6) * (n10 / n9) * rot10)

To make it "south-pointing" requires, that if rot₁ is held 0, rot₁₁ has to be exactly one turn when wheel 10 of diameter d₁₀ covered one full circle (centre at wheel 1's contact to the ground, radius equal to track width t):

(j:)	d10 * rot10 * PI = 2 * t * PI		d1 * rot1 * PI = 2 * t * PI
(k:)	rot1 = 0		rot10 = 0
(l:)	rot11 = -1		rot11 = 1
(i=>)	rot10 = 2 * (n11 / n4) * (n6 / n8) * (n9 / n10)		rot1 = 2 * (n11 / n4) * (n2 / n1)
(j=>)	d10 = 2 * t / rot10		d1 = 2 * t / rot1

The same method can be applied to calculate the required size for wheel 1, see rightmost column of table above.