Team 701 20+ Foot Puncher Prototype

This is the puncher prototype we used today to test shooting distance. The puncher isn’t even cocked back all the way to allow us to not overshoot. We’ll be using the same energy storage method for our final design, but the ball won’t be at the front. Hint, hint.


Said the RoboVikes.

I’m pretty sure this was every team’s reaction to the first of many times a goal is made. It’s a very exciting moment.

It really was. We’ve prototyped and prototyped, tweaked this tweaked that, and tried all kinds of stuff from trampoline springs to gas springs to catapults, and finally we made a goal from a distance!

If only we could build in an environment where an undershirt could be worn outside …

The sunny weather these days makes for a pleasant build season for sure. But it isn’t necessarily all good in the big scheme of things, water rationing is starting in several counties in Northern California…

I wouldn’t mind some rain (and snow in the mountains), otherwise it will be a tough spring and summer for california.

What source of stored energy are you using? Also, about how much stroke are you getting from that puncher?

True with what Doug said. We’ve only had around three rainy days that I could recall since last spring, and our county and surrounding areas are still brown from the summer, since it doesn’t rain in the summer here, except for the beginning of June some years. Usually, the rain comes down nearly every day starting October or November until march or April, and this drought has me worried. This is supposed to be our winter wet season, and it feels like we’ve skipped that and gone back straight to spring. It’s so anomalous. It does feel nice outside, with the sun out to warm up the day, but it’s not exactly for the better of our environment here in Solano County.

Also consider that the one wearing the undershirt is our mentor Karan, who will probably wear one no matter what weather anyway. He’s a character.

Nice job 701!

It looks like you are launching from about 3’ in the air. Is this where you will be launching on your bot? If not, try it from your proposed height, you may find your trajectory will be quite different. Either way, I know you will dial it in. It’s just the RoboVike way!

Really cool shooter! Do you think that maybe you could help our team out by giving us a few specs and details? Thanks!

We would gladly trade you California folks! We were in the middle of the so called Polar Vortex. We have had several days with highs only in the single digits. And Erie PA leads the nation in snowfall for cities of 100,000+ in size. A full foot ahead of number two. Such an honor we would gladly trade!

But…we’re in a water shortage.

Bedhed, we are bummed you guys aren’t coming to Denver this year! When you pushed us out of the way in semis last year, it inspired us to build a much better drive base. We wanted to take you on again…

Nice long shooter, btw.

A rematch will have to happen sometime in the future. Maybe take a trip to sunny California and participate in the Sacramento Regional! Glad my team could inspire your team to improve themselves. Maybe your new drive base might put ours to shame!
I’m assuming that this is the match you are talking about.

Most of the credit actually goes to 2259. I directed them to push, and in some instances, for our team to push behind them for extra force. The double pushing is actually a derivative of one of my pre-written match strategies called “Caterpillar,” where all three robots on the alliance drive bumper to bumper towards a goal as an offensive strategy to prevent defending robots from pushing. The other team would be forced to forego their offensive strategy in order to stop our offensive strategy, since two defense robots still would have a difficult time against three robots in line.

If you look to the left at the alliance station, you can see me going back and forth between alliance stations coaching the other teams. Communication was super crucial for this strategy.

We used 6 loops of surgical tubing, which creates 12 segments, each about 4" long when unstretched. The tubing is fairly thick, maybe 1/2" OD, 1/4" ID. Stroke in the video was about 8", but it went from a 12" position to a 4" position. The dog got caught in a nearby gear, when we released it.

It is very important to pay attention to detail when using this style of launcher. We almost gave up on it a few days prior, but redesigned it to have more stroke length, which made a huge difference.

Our latest revision will only have 12" of stroke and will incorporate the use of a sled / seat to propel the ball. The ball will not be launched from the end of the mechanism as shown in the video… at least we are hoping not too. We just finished the CAD for it today and will assemble the new one in the next few days.

As said numerous times elsewhere, scoring the ball is meaningless if you can’t pick it up and pass it off quickly and efficiently. It is scary how distracting the scoring mechanism is for teams. DESIGN your robot to pick up and pass the ball too!

CIM motor with 12 tooth pinion to 48 tooth gear on the first stage. 20 tooth to 36 tooth on the second stage. 20 tooth to 35 tooth AndyMark Dog gear on the third stage. The third stage uses the AndyMark long shifter shaft and a custom made spool which winds up the nylon strap pulling back the “piston”. Attach a bunch of surgical tubing to the piston base and the front of the launcher and there you go. Our next version is redesigned so it uses a minicim and a GEM500 gearbox in conjunction with the dog shifter/spool assembly so as to simplify the gearing. It will also include a sled launching approach, instead of at the end of a piston. Hopefully it works just as well, if not better.

Thanks Bill for the advice. Our next version will be shooting from about 15" from the ground. So it will surely be a different trajectory.

It looks like your shooter/arm setup is quite similar to what we have been prototyping! Nice job on the 20 foot shot, it looks to be really effective.

Ah, that was a fun semifinal! Thanks for the video link, it’s one of the better ones I’ve seen from that competition. I’m the human player for 1332 in that video. You guys certainly pushed us around. Our rookie team this year has built a much sturdier drive train for the same reason as our alliance members on 1339 (who were excellent, by the way!).

What kind of drive system did you have for your team that season?

4-wheel tank drive, with plaction wheels on the back and omnis on the front. It was reasonably effective, but we felt like the omnis in front were limiting our pushing power. This year, 4944 will be using six plaction wheels.

We stick with the six wheel aluminum treaded wheels with a dropped center wheel. That’s what we used last year, and we are using it again this year.