Who still thinks pneumatic catapults won't work for this game?

We came up with a term to help explain what we have done with pneumatics this year. We call it an articulated pneumatics system. It consists of using pulses to the solenoids to get the desire power from the catapult and using two variable synchronized pneumatic systems to adjust the trajectory of the ball as it sits on the catapult before the catapult launches. It has been working beautifully. We can get any trajectory we want and have the shot sequences programed to the game controller. We believe this we key to us winning the AZ regional this year. We used the KOP chassis and a pinching D-arm mechanism that rotates from the ground to the catapult. The pitching mechanism was also done by a set of cylinders. We were receiving criticism for choosing pneumatics and for the our arm design. It looks like the criticism was for not… lets see how we do at championships. we currently have 117.75 OPR,…not bad eh?

Pneumatic catapults are definitely viable and the use of pulsing to vary shots are effective.
We definitely used your idea in addition to other mechanical ones in order to achieve high goal shots.

OPR though to me is over-rated. Up until the last Quals match in NL during Week 2, we were well over 100. From that point on and in Dallas the following week, we shifted our focus to just assists, and the role we played differed in eliminations in Dallas as well.
I would like to believe that your alliance won primarily due to having the best teamwork and execution vs. your opponents.
At CMPs, I see it as being no different than what it took at the regional level play. When scouting, our team hasnt and wont even bother to look at OPR as a basis for selecting teams, if in the top 8 alliance captain position.

Congratulations once again on winning the Arizona regional!

We built a pneumatic catapult. Nothing fancy, just two somewhat largeish cylinders (lot smaller than one behemoth I’ve seen), two double solenoids, and a swiss-cheesed bar of c-channel. We were finalists at Traverse City.

Pneumatic catapults WORK.

*The losses in finals were probably because of our drive chain literally falling off.

Edit: after reading the following comments - we don’t need no stinking pulsing. :slight_smile:

Ours worked GREAT…allowed our second year team to make eliminations at the Boilermaker Regional.

Thanks to both 359 for highlighting your discussion regarding pulsing…that was the secret to success…along with high flow valves.:slight_smile: :slight_smile: :slight_smile: :slight_smile:

Works for us too. Turning on the solenoids for a full second gives us our long shot. We do a couple millisecond for a short/goal shot.

842’s catapult design is unique and very effective. When our team first saw this game, we knew pneumatics was our plan. Since then, we have had nothing but success with our pneumatic catapult, which is amazingly similar to 842’s. With this design, we can make just about any shot by pulsing. It helped us win our first ever regional this year in San Diego.

I would like to thank 842 for posting their ideas early in the season. It was nice for our students to see that we weren’t the only team thinking this way. Pneumatic catapults are here to dominate this season. I also feel they are a lot safer in the pits then a lot of the other elastic and spring mechanisms I have seen.

2996 won the Utah regional with a very straightforward pneumatic catapult. Perfect for the “protected” high goal.

That is funny because I tell that to my team all the time, but I jumped on the chance to brag about it when we have been ranked so high! It lended convenient validation for our design choice after being told what we were doing was the wrong approach.

Oh yes we definitely won the regional because of the alliance, I was just using the opr to rationalize our design choice

We used a pneumatic catapult this year with two 10 in stroke, 1 1/2 in bore pistons, and c-channel with ‘speed holes’ :stuck_out_tongue: and bent flatstock. We ended up as finalists at Centerline, and got our highest pick in team history, so yeah, I’d say the pneumatic catapult played a part.

I would like to thank 842, though, because until my team saw their catapult prototype video, our team had no intent on building a shooter. :smiley:

Team 2137 used their pneumatic catapult to seed #1 after quals at the FiM Great Lakes Bay Region District event. We had a nearly flawless 2 ball auton throughout quals and eliminations.

I dissed the idea of a pneumatic catapult early in the design process. I was soooo wrong. We have seen many nice pneumatic-based designs.

Oh yeah…high qualifying score (match Q06) of the Arizona regional was 235, made by 842 and 1726 (4496 did not make it to the field). Both robots have pneumatic catapults.

624 went with a pneumatic catapult as well this year; its consistency combined with a pretty good trajectory lets us shoot from almost anywhere in the forward zone and truss with the same shot. We don’t really even have to vary the shots; same shot for truss, for moving while shooting, for stationary shots at the one point goal or farther away, it’s quite interesting how it turned out. I would say it’s made a good season for us so far!

The video we posted of our pneumatic catapult prototype was viewed almost 800 times. I had the pleasure of having someone come up to me at our regional this weekend and tell me that their catapult was based on the video we posted. Such a compliment!

After posting the prototype video, the design evolved drastically. By switching from one to two cylinders we found that we decreased our air consumption. We use high flow servovalves and pulse to get variable trajectory shots, though we’ve found that pulsing consumes a lot of air.

We experimented to find the lowest system pressure which produced a consistent trajectory shot. We added a pressure sensor to our HP supply to monitor pressure. We use a spike to power our camera light ring and a LED strip on the other side of the robot. When the pressure drops too low for a good shot, the lights turn off. That way, as long as the lights are on, the driver and operator know, without taking eyes off the robot, that the pressure is good.

It works great. We used it to get what we think was the highest un-penalized match score at our regional. Video here. Notice that we started just a little low on our precharge pressure. The indicator lights go off during the second auto shot, and it falls a tad short. After that, you can see the lights going off during the match as we operate the pneumatics and consume air, and then back on as the compressor catches back up.

I’d sure be interested in seeing the code for pulsing the solenoids. Any chance of sending me a copy via pm? I’m sure that if I see it I’ll slap my head and wonder why we didn’t think of that. I think I can count the number of times you guys missed a shot at the AZ regional on two fingers.
Congratulations again on your win. I think that makes four in a row for 842.

We are moving to a pneumatic launcher from a motor driven one. We liked the motor driven launcher but couldn’t replicate practice field results on the competition field. Hopefully we won’t have the problem with the pneumatic launcher.

Video of us testing the launcher at Texas Torque World Headquarters.

That intake though!

I was pretty skeptical about pneumatic launchers at the start of the season, and helped get it eliminated from the prototypes we would make. Well, we are now using a pneumatic catapult which works better than anything else we made. It all depends on the kind of hardware you use.

One advantage of the pneumatic catapult for our team, is it’s utter simplicity. It has one fabricated moving part.