Re: non-pneumatic "kicking" mechanism
 

I see. Your earlier post mentioned something about being able to adjust the tension and I mis-interpreted that as meaning you could adjust the tension of the kick during a match.


The temperature effect would be an intrinsic property of the material itself (latex), not the wall thickness.

If you are concerned about temperature, you could run a very simple experiment. Hang a 10 pound weight from a section of surgical tubing and measure the stretched length at room temperature. Then go outside in the cold and repeat the experiment (after letting the tubing cool down of course).

You can then very easily interpolate these results to the range of temperature differences you think might be reasonable to expect in the competition venue. Knowing the spring rate of the section of tubing you used for the test, you can calculate the expected change in force.


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Re: non-pneumatic "kicking" mechanism
 

Adjusting the tension is a completely different system. The motor pulls the arm back and allows it to swing. A separate system will control/adjust tension.

Re: non-pneumatic "kicking" mechanism
 

Nice approach. Different from others I've seen so far.


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Re: non-pneumatic "kicking" mechanism
 

Take a look at this. (There are three pictures following, just click on the right side of the pictures.)

As the wheel turns, the lone pin locks against the offset link, forcing it to rotate with the wheel (rather than just pivot). When the link hits the "12-o'clock" position, the pull to the right causes it to spring back very quickly. (NOTE: The surgical tubing is there to provide resistance for this demonstration. In final design, it would be a direct link to the kicker, which itself would be propelled with surgical tubing.)

Re: non-pneumatic "kicking" mechanism
 

What are the material limitations in order to strike the ball

Re: non-pneumatic "kicking" mechanism
 

Mister I,

That is a GREAT idea for a kicker. Elegantly simple, yet surprisingly complex.

Dang, that sounds like a sommelier...

We have circled all around that design and whiffed, but you guys hit the target dead on.

Nice job.

Re: non-pneumatic "kicking" mechanism
 

seems familiar....:p

http://www.chiefdelphi.com/media/photos/31539

Re: non-pneumatic "kicking" mechanism
 

This is the same system I was explaining (or trying to) it works very well

Re: non-pneumatic "kicking" mechanism
 

I wonder if this design could be set up to provide a strong kick when running the motor one direction, and a weaker kick when running it the opposite direction?

let's put on our thinking caps :)

Re: non-pneumatic "kicking" mechanism
 

That's an easy one! The two designs we considered were a pneumatic one, which we're using, but one could also make a quick-return 4-bar linkage driven by a CIM or FP, or two FP, that would swing quickly in one direction and slowly in the other. Simple in concept, but more difficult in application.

Re: non-pneumatic "kicking" mechanism
 

A little hint at our design with no pneumatics:

This

And This

And This

Re: non-pneumatic "kicking" mechanism
 

valve springs from a car could easily do that

Re: non-pneumatic "kicking" mechanism
 

Imitation is the sincerest form of flattery, and yes, that picture is where we got the original idea from. (I just couldn't recall "1625" when I made the post yesterday.)

Re: non-pneumatic "kicking" mechanism
 

We posted our kicker on youtube

http://www.youtube.com/watch?v=fhM-N4a_O-Q

the quality is not the best but it shows that same concept that is being discussed. The spring tension is relatively low for this test. With a higher tension (more tubing or attaching ther tubing further back) we can get more distance.

Re: non-pneumatic "kicking" mechanism
 

We made a prototype kind of like that, but realized that controlling it would be very difficult...because we want to be able to hold the kicker back so that we can control the ball (have it at the front of the robot while driving around), then be able to kick it. Getting the motor to stop at the top of the rotation looks to be challenging.