Cheap Mechanical Device for Intermittent Motion

[Seraph042]

Does anyone know of a cheap mechanical device which is able to achieve specific intermittent / discrete motion along a shaft?

 

[berkeman]

Does anyone know of a cheap mechanical device which is able to achieve specific intermittent / discrete motion along a shaft?

What kind of motion? Like a crawling motion? How fast? can the shaft have threads, or does it need to be smooth?

I remember a linear motor mechanism that I read about once that could move on a smooth shaft because it had two gripper mechanisms (one at each end), and an extension capability in the middle. I forget what the application was, though.

 

[minger]

Cam/Roller setup?
http://en.wikipedia.org/wiki/File:Nockenwelle_ani.gif

 

[Seraph042]

I'm trying to rotate a shaft 60 degrees every 30 seconds; right now I'm looking into some sort of toothed gear / ratchet powered by a linear solenoid actuator... I'm still working on figuring out the details but it could work.

do you guys agree with that or should I be looking at something else ??

 

[DaveC426913]

...intermittent / discrete motion along a shaft...

... rotate a shaft 60 degrees every 30 seconds...

Which is it?

 

[Seraph042]

Sorry, I meant to say the latter in the original post (I can't update it for some reason)