Installation of pneumatics in catapult

My team finished building their robots but we have a problem, when we installed our 2 single acting cylinders into the catapult and tested it, the ball got stuck with the intake that we use to take them. We then built something for the ball to stay higher and the pneumatics didn’t had the force necessary to push them to the goal zone of the field. We need help, can someone tell us what do we have to do so our robot can push the balls farther?

Photos would be really helpful.

Seriously that is the only hard part on the entire catapult. Maybe if you show some pictures and videos of what goes wrong we can offer advice but your not even being clear if its a front or back catapult just “let me copy catapult now”.

I find that the attitude is unnecessary , because in the forums you can solve the problems that you have with your robot. I only posted this thread because I had a problem with my front catapult and I was asking for help. As you say, the installation is the hardest part, well I’m in that part and have no successful results.

If someone could actually help it would be great, because we always use new ideas, not internet stuff, that’s what have distinguished our robot from others. But this is our first time using pneumatics so we need help because we still don’t know how to use them very well.

http://www.team323z.com/gamma-titan-v20.html.
Here are some good pictures of a catapult that shoots very well.

https://lh4.googleusercontent.com/-OMUFXbwyxqk/Uzb2eByAcrI/AAAAAAAAC8Y/bIjgmnI30Io/w757-h568-no/2014-03-29

https://lh5.googleusercontent.com/-IOBv78IHYbs/Uzb2Vun_PtI/AAAAAAAAC8A/QC6U9IM0TFU/w757-h568-no/2014-03-29

Robo-Summant that catapult seems really complicated, it’s really nice though… Here are pictures of our catapult.

Although my robot doesn’t have a standard catapult, from helping some other teams with their’s, we found that the spring return on the single-action pistons took some significant distance away.

If possible, you guys might want to try and get some double-action pistons and just not power the pull back. It would give you the effect of a single-action without the spring that retracts them taking away power.

Good Luck!:smiley:

Thanks a lot! We will try to buy them :slight_smile:

I can’t see further up on your tray, but do you have a mechanism so that the balls go further towards the back. This will make sure that the ball doesn’t get caught on the intake and also the ball will be thrown further.

Single acting don’t have enough power get double acting that just actuate one way

Team 7793r has a great video of their catapult http://m.youtube.com/watch?v=MFdfHArsNZk

Yeah, I think we have to make a better system so the ball goes further to the back and yeah, we have to buy double acting cylinders.

Thanks a lot to all of you for your generosity.

Also, I am sure you can contact either Jesse323z or 7793r (Stanley Shi) for more questions. They have been really helpful all season.

I have noticed that where you mounted the piston the catapult bar, you have used a screw and a keps nut. There is probably a lot of resistance in that joint, and from the looks of it must be unscrewing itself pretty often. **Using an axle and shaft collars or a screw and nylock nuts will give you better performance.
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There are also some other things your catapult is probably lacking. I have observed that it is a replica of mine :P, but you are using single acting pistons. My point is not that the single acting pistons are weaker(you already know that) but the single acting pistons come with really crappy solenoids. They are not nearly as good as the double acting solenoids because the airflow rate is so small in the single acting solenoids. Enough to actually weaken the power of the catapult drastically compared to if you were to use a double acting solenoid. This reduced flow rate inhibits the acceleration of the pistons which is important for the catapult. So to conclude, use double acting solenoids, not single acting.