Pneumatic Ball Puncher

[thinker&planner]

Originally Posted by Brandon Zalinsky

I guarantee at least one robot on Einstein will use a pneumatic punch, either one large cylinder or 3-4 smaller ones.

I can almost guarantee that there will not be a successful robot that uses one giant piston for this reason: You are extremely limited to the amount of air that you can get into a giant piston by tubing and fitting size, not even accounting for valve size.
That being said, I believe that it will be possible to use multiple smaller pistons to launch the ball at a decent rate.

[Ed Sparks]

Look at the pneumatic rules very closely. There are deliberate specs in these rules to slow down the transfer of energy from the holding tank to the actuators (small valves, small id tubing, 60 PSI working pressure). At some point, given the mass of whatever were tossing, the physics just doesn't work out. If we were allowed to use 1" actuated ball valves and 1" tubing ...... well ...... we could be having some chunk'n fun.

[czeke]

Keep in mind, that using a punch, similar to Team 1114 from 2008, also allows you to shoot straight ( towards an alliance partner for an assist ) &
tilting forward ( to harvest a ball from the field ). Plus, if designed with some reinforcement, could make somewhat of a mitt, for catching.

[Zealii]

Originally Posted by czeke

Keep in mind, that using a punch, similar to Team 1114 from 2008, also allows you to shoot straight ( towards an alliance partner for an assist ) &

tilting forward ( to harvest a ball from the field ). Plus, if designed with some reinforcement, could make somewhat of a mitt, for catching.

This was exactly my teams idea before we prototyped. In theory, yes it would be the perfect design. After actually prototyping it, we found that the air flow through the required tubing was not high enough to actually move the ball more than a few inches off the stand. We did try many different cylinders with similar results.

[Bruceb]

Not sure what cylinders you used but we tested with 2 3/4 inch cylinders of about 8 inches of throw hooked up back to back and triggered with 2 separate valves and got about 4 ft of throw.
Gonna try 3 pairs of 9/16 cylinders tonight.

[czeke]

Zealii, sorry, I wasn't implying pneumatic cylinders, I was implying using stretched surgical tubing to provide the punching force.

[Kevin Sevcik]

Originally Posted by Bruceb

Not sure what cylinders you used but we tested with 2 3/4 inch cylinders of about 8 inches of throw hooked up back to back and triggered with 2 separate valves and got about 4 ft of throw.
Gonna try 3 pairs of 9/16 cylinders tonight.

What were you using for valve, tubing, etc.? Are you certain this was an FRC legal setup?

[Brandon Zalinsky]

Originally Posted by themccannman

I seriously doubt that. Maybe pneumatics attached to a lever arm to throw the ball, but absolutely not to punch it.

Mark my words.

One cylinder got our team an undefeated qualifications in 2008. I'm loving your "absolutely not" certainty- our punch prototype shoots 25 feet. I repeat my guarantee- at least one team on Einstein will have a linear pneumatic punch shooter.

[bbradf44]

Originally Posted by Brandon Zalinsky

Mark my words.

One cylinder got our team an undefeated qualifications in 2008. I'm loving your "absolutely not" certainty- our punch prototype shoots 25 feet. I repeat my guarantee- at least one team on Einstein will have a linear pneumatic punch shooter.

Can I ask what your setup is? Like what kind of piston and flow rate? Despite warnings from others on here my team is planning on a punch shooter but we don't have enough materials to build a full working prototype then another one for the robot

[Ether]

Originally Posted by Brandon Zalinsky

our punch prototype shoots 25 feet

Are you using the cylinder end cap as the hard stop?

[martin417]

I was about to get up on my soapbox, but the topic seemed so familiar that I looked at some of my old posts and found this one from 2008.

The post atarts with this quote:

"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."--Arthur C. Clarke

When you act as an expert and tell people that that "it wont wok", you are not inspiring them, you are preventing them from exploring and learning.

By the way, after that post was made, the team was invited to attend championships, played in the quarterfinals there, and won the Xerox creativity award.

Please read the post and think before you stifle creativity.

[PANTHERPROJECT]

Team 2064 made prototypes for a pneumatic catapult instead of the ball puncher because we had absolutely no luck with the puncher, however the catapult is making progress. We're trying out different solenoids to see which one works best and I suggest that you do the same.

[DRH2o]

We have tested with four 3/4" X 10" stroke cylinders with a festo solenoid valve per cylinder and an accumulator feeding each valve at 60psi and have been able to get about 7 feet straight up from the ball resting on top of the cylinders that are spaced evenly around a 4" diameter tube. We were getting 4' with three. We plan to use 6 and hold with vacuum next test. Will let you know how it works... Not a punch -- more of a put (like shot put).

[Brandon Zalinsky]

Originally Posted by bbradf44

Can I ask what your setup is? Like what kind of piston and flow rate?

We're using multiple 3/4", 12" stroke cylinders which each have their own solenoid and dedicated accumulator on the 60psi side.

Originally Posted by Ether

Are you using the cylinder end cap as the hard stop?

[i]

Yes

[Ether]

Originally Posted by Ether

Are you using the cylinder end cap as the hard stop?

Originally Posted by Brandon Zalinsky

Yes

May I ask, what is the part number of the cylinder?