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Gear constraint (proportional normal 'twist'?) (by srhlefty)
Hi there, first off I love this software so much! I am a bit of a newbie at this, though I have done some stuff in SolidWorks.

My question is, when doing an assembly, is it possible to constrain the orientation of parts with a proportional angle type of constraint? What I'm getting at is the ability to simulate gears. It seems like it would be a straightforward constraint: the twist of part B's normal is equal to the twist of part A's normal times a constant (the gear ratio). I think the only subtle point is the wrap around issue once you've rotated something past 2pi.

I've been studying the SAME_ORIENTATION code in constrainteq.cpp, it's so close :)
Sun Nov 12 2017, 01:01:20
gears with ratio of 1:4 (by Rudi)
Tusi couple Mechanism.
Straight Line Mechanism that I use for same purpose.
Hope it helps.
(no subject) (by User1)
@Rudi, very nice example of Tusi couple! So, using this principle its possible design mechanisms with ratio 2:1 for two gears, or 4:1 for three gears, etc.

@srhlefty, in SolveSpace not so many constrains availiable, but if you know well mechanics, kimlnematics, geometry and math -- you will find many solutions how make any mechanism in SolveSpace ;-)

> I've been studying the SAME_ORIENTATION code in constrainteq.cpp, it's so close :)

I think, maybe in future SolveSpace will get "Rotation" constrain.
Sat Jan 13 2018, 20:59:41
Gear Assembly (by JustThinkering)
Hi srhlefty,

with the help of some auxiliary lines it is also possible to assemble gears with arbitrary gear ratio (unfortunately, after one revolution the drawing often breaks):

Constrain the position and orientation of two gears to two arcs, whose distance is the sum of the reference circle radii. Then, make the length of the arcs equal to a line and control the gear ratio by the arcs diameter ratio.