Mechanisms

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EpicentrE
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Joined: Mon Jun 09, 2003 12:00 am
Location: Coventry
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Mechanisms

Post by EpicentrE »

Hi All,

I had a look around and couldn't find a topic that I thought this would fit in, so I'm making a new one. People could use this thread in the future if they're having trouble working out a mechanism or system that achieves something that they need.

My issue is I've got an idea for an ant, and while I could make it simply, that simply isn't me, as those of you who know me will know. I need a mechanism that will, ideally, do this:

1 input, either rotation or linear
4 outputs, either rotation or linear
Outputs are "linked", in that they all move together. However, if one output is stalled, the power will be transferred to the other outputs

The best examples I can think of are a pneumatic/hydraulic system, where you had a pressure source connecting to 4 rams. If one ram is stopped, the other rams would move faster, until all the rams are stopped, in which case all rams would get 1/4 of the overall force. Make sense?

Another example would be having the input turning a differential, and then each output turning another differential. Each differential could have one of it's shafts stopped and the other shaft would go twice as fast, and if one differential was stopped completely, the other differential would turn twice as fast.

Unfortunately, both of these ideas are way too complex or simply not possible in the size that I've got. I can't help thinking there's some kind of super clever awesome lever-based mechanism or something I've not thought of that could achieve this. Does anyone have any ideas?
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk
daliad100
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Re: Mechanisms

Post by daliad100 »

Would allowing slip in the drive via a friction clutch or belt work?

Static friction coefficient (not slipping) is generally more than Dynamic friction coefficient (slipping) so when the output shaft is stalled the load on it is reduced making more power available to the other outputs.

I may be talking total nonsense but it's the only way I can think of that would fit in an ant.
Team Imperial - What is that, metric?
EpicentrE
Posts: 831
Joined: Mon Jun 09, 2003 12:00 am
Location: Coventry
Contact:

Re: Mechanisms

Post by EpicentrE »

The robot will be a grabber (of sorts, you'll have to wait and see), so having the outputs slipping really isn't an option, as there would be no force in the nom (which is definitely a technical term). My backup plan is to have springs on the final outputs (which will be linear), so when one output gets stalled it doesn't affect the others, but then it's wasting force in compressing the springs, and the outputs still can't move independently, so they're always in the same positions.

Maybe there is no solution, and I'll just have to use the above, but I thought it was at least worth asking in case there was something I hadn't thought of :).
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk
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