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Subject: 
Re: Discontinuous motion.
Newsgroups: 
lugnet.robotics
Date: 
Thu, 4 Apr 2002 18:39:02 GMT
Viewed: 
573 times
  
Steve,

  If the precision is due to the axe slipping while not being
driven, you could consider using a pully off a micro-motor.
It has a friction slip mechanism at one end, and an axle hole
at the other.  You could use the axle hole to stablize the
pully with respect to the framework, and then the friction
slip part would stop the undriven axle from turning due to jiggle.

Kevin mailto:kevin_clague@yahoo.com

"Steve Baker" <lego-robotics@crynwr.com> wrote in message
news:3CAB4525.8112CA4A@airmail.net...
"Kevin L. Clague" wrote:

You can do this without modifying any gears.

To approximate a gear with teeth missing, all you need to do is have
the axle that drives the gear offset from the center of the gear.

For example on a 40T gear, just use one of the axle holes that is
not in the center of the gear.

I've tried that - it jams periodically when the teeth of one wheel
meet point-to-point against the teeth of the wheel it's driving.
This seems to be because of the strange angle at which the first
wheel approaches the second at it initially meshes.

HOWEVER: I have finally found a mechanism that works:

   http://www.sjbaker.org/steve/lego/discontinuous.html

...but it's still not really *precise*.

----------------------------- Steve Baker -------------------------------
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URLs : http://www.sjbaker.org
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Message has 1 Reply:
  Re: Discontinuous motion.
 
I've uploaded a simple detent mechanism which can be used to stop shafts creeping round when they're not supposed to. The only drawback is it can get rather noisy :) (URL) black shape at the top is supposed to represent an official Lego rubber band. (...) (22 years ago, 4-Apr-02, to lugnet.robotics)

Message is in Reply To:
  Re: Discontinuous motion.
 
(...) I've tried that - it jams periodically when the teeth of one wheel meet point-to-point against the teeth of the wheel it's driving. This seems to be because of the strange angle at which the first wheel approaches the second at it initially (...) (22 years ago, 3-Apr-02, to lugnet.robotics)

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