Peumatics or Motor?!?!?!?!

[GaryVoshol]

Originally Posted by emo Sponge

if your arm sticks out you should use peumatics
if it does not use a motor
peumatics are not realy safe

Originally Posted by emo Sponge

our team has a peumatic catapult and it is very dangerous
if the air compresor became faulty it could set off the catapult and injure someone

Your team has posted some marvelous information about your robot, and how they are taking safety precautions. I think you'd better find out just what your team is doing before you criticize. Your posts do not present a good image for your team.

[emo Sponge]

Originally Posted by rocketperson44

Yes, but it would be just as dangerous if it was motor powered. Anyways, either way, proper precautions to limit the risk of injury should be taken.



Back to the arm, it sounds like you are not completely sure over whether it needs more than 2 positions. In this case, motors would probably be advantageous. If you are not sure, than that (correct me if I'm wrong) means that you are probably not sure what the third position would be. As others have said, using sensors/mechanical stops/multiple cylinders, it is definatly possible to have 3 or more pneumatic positions. However, it is much harder to make these positions variable. Motors will allow you to put the arm in any positon needed, with no tricky mechanical work.

If you are sure, then the simplest way to do it would probably be what EricH suggested:

http://www.putfile.com/pic.php?img=7596589

your totaly right about the precautions

[CCCP]

go with the motors

[M'gnad-knockah]

the other downfall to pneumatics is the efficiency, pneumatics only have a 4% efficiency, which sucks because the compressor has to run, and waste battery power.

[IndySam]

Originally Posted by M'gnad-knockah

the other downfall to pneumatics is the efficiency, pneumatics only have a 4% efficiency, which sucks because the compressor has to run, and waste battery power.

where did you get that number?

[M'gnad-knockah]

its common knowledge

[EricH]

Originally Posted by M'gnad-knockah

its common knowledge

We don't know it here... Go look at the books again. (Or I know who to ask, when I am at competition.)

[Vikesrock]

Originally Posted by M'gnad-knockah

the other downfall to pneumatics is the efficiency, pneumatics only have a 4% efficiency, which sucks because the compressor has to run, and waste battery power.

Assuming this number is true, it needs more clarification. 4% efficiency in what sense? 4% of the potential in the compressed air is converted to kinetic in a moving cylinder? 4% of the electric potential to run the compressor is converted to potential stored in the tanks? 4% of the electric potential to run the compressor is converted to kinetic in a moving cylinder?

[dlavery]

Originally Posted by M'gnad-knockah

its common knowledge

Actually, without a citation and/or verifiable reference, it is nothing but a common made-up number. Sorry, but saying"pneumatics only have a 4% efficiency " is just not credible without providing more information to back up the statement. Facts are preferred over conjecture.

-dave



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