Type "ODTS 1"

This design started as inversion of the "Morris" type, with the aim to avoid the reversal gear for the platform. Well, it works but the road wheels need to be ridiculously large. On the other hand the track width can be made really small!. The adapted equations:

(a:)	n₄ * rot₄ + n₉ * rot₉ - (n₄ + n₉) * rot₃ = 0
(b:)	n₂ * rot₂ - n₃ * rot₃ = 0
(c:)	n₆ * rot₆ - n₇ * rot₇ = 0

The remaining constraints:

(d:)	rot₁ = rot₂
(e:)	rot₄ = rot₇
(f:)	rot₅ = rot₆
(g:)	rot₉ = rot₁₀

Composition (POV is from top respectively from far right):

(d=>)	rot₁ = rot₂
(b=>)	= (n₃ / n₂) * rot₃
(f=>)	rot₅ = rot₆
(c=>)	= (n₇ / n₆) * rot₇
(e=>)	= (n₇ / n₆) * rot₄
(a=>h:)	n₄ * (n₆ / n₇) * rot₅ + n₉ * rot₁₀ - (n₄ + n₉) * (n₂ / n₃) * rot₁ = 0

To make it "south-pointing" requires, that if rot₅ is held 0, rot₁₀ has to be exactly one turn when wheel 1 of diameter d₁ covered one full circle (centre at wheel 5's contact to the ground, radius equal to track width t):

(i:)	d₁ * rot₁ * PI = 2 * t * PI
(j:)	rot₁₀ = 1
(k:)	rot₅ = 0
(h=>)	n₄ * (n₆ / n₇) * 0 + n₉ * 1 - (n₄ + n₉) * (n₂ / n₃) * rot₁ = 0
	rot₁ = (n₃ / n₂) * n₉ / (n₄ + n₉)
(i=>)	d₁ = 2 * t / rot₁

The same method can be applied to calculate the required size for wheel 5: If rot₁ is held 0, rot₁₀ has to be exactly one turn when wheel 5 of diameter d₅ covered one full circle (this time centre at wheel 1's contact to the ground, radius equal to track width t):

(l:)	d₅ * rot₅ * PI = 2 * t * PI
(m:)	rot₁ = 0
(h=>)	n₄ * (n₆ / n₇) * rot₅ + n₉ * 1 - (n₄ + n₉) * (n₂ / n₃) * 0 = 0
	rot₅ = (-1) * (n₉ / n₄) * (n₇ / n₆)
(l=>)	d₅ = 2 * t / \| rot₅ \|

Reference	Size	Description
2	n₂ = [teeth]	Bevel gear, fixed to wheel 1
3	n₃ = [teeth]	Bevel gear, fixed to vertical shaft
4	n₄ = [teeth]	Bevel gear, freerunning on vertical shaft
6	n₆ = [teeth]	Bevel gear, fixed to wheel 5
7	n₇ = [teeth]	Bevel gear, fixed to wheel 4
8	n₈ = [teeth]	Bevel gear, freerunning on horizontal shaft, which in turn is fixed to central vertical shaft
9	n₉ = [teeth]	Bevel gear, freerunning on vertical shaft
10	-	Pointer platform, fixed to wheel 9
T	t = [length units]	Track width

Reference	Size	Description
1	d₁ = [units of t]	Roadwheel, freerunning on axle
5	d₅ = [units of t]	Roadwheel, freerunning on axle

Type "ODTS 1"

Given Parameters (Your choice !)

Derived Parameters