Catapult/PTO Explanation | VEX Spin Up | 2654P Pronounce This

Specs:
8 motor drive, 450 RPM on 3.25 omnis
2 motor cata, 22 RPM
2 motor intake, 1200 first roller, 600 second
2 piston PTO
1 piston expansion 💀

[@PPronounceThis]

Only match I have of this robot: kzbin.info/www/bejne/moC9o2ikp7NlbZY

[@jadensmith2191]

I would like to know if you have a fusion design file of this? Thank you!

[@PPronounceThis]

@@jadensmith2191 Unfortunately, we are not going to leak our CAD model, and we would like to encourage teams to potentially take inspiration from us, but not copy our design hole for hole.

[@jadensmith2191]

@@PPronounceThis that's entire fair. I mostly wanted to know your pneumatics setup in greater detail. Last competition we did not have a horizontal expansion, because we didn't know how pneumatics really worked. I'm attempting to figure out how to design cannons, catapults, and other devices using the pneumatics I have (only one cylinder and one piston). If you have any tutorials along those lines, that would also work!

[@PPronounceThis]

@@jadensmith2191 This is a video detailing how pneumatics work: kzbin.info/www/bejne/mHPFZZxsjJaVrc0. In addition, we have some videos of prototype endgame designs on our KZbin channel.

[@gumby5068]

I’m more interested in that inertial sensor mount. Looks clean af

[@Elizafys]

This is SICK! post actual matches the robot is super innovative and it looks like it works amazingly well

[@PPronounceThis]

We’ve only done four matches with this robot, but we’ve only recorded one of them. I can post it but we’re the only robot that does anything.

[@Elizafys]

@@PPronounceThis would be awesome to watch!

[@bennguyen3089]

Very cool concept

[@eddo1569A]

this is some great stuff

[@ali-1353]

nice

[@vapor1148]

nice robot

[@markelfbrandt3000]

Cata op

[@KennyGreenBean]

Nice robot! But I just have one question. You mentioned you had a ratchet that prevented the catapult from launching when you had all 8 motors on the drive, but how would you launch the catapult when you wanted it to? The ratchet would prevent it from going up right?

[@PPronounceThis]

The ratchet is on the gear train below the slip gear so the catapult can move both directions, but the slip gear cannot.

[@KennyGreenBean]

@@PPronounceThis ohh. That's smart. Very cool!

[@trollface.png1633]

3:57 just link to our vid on the passive mech

[@declancraig6810]

May I ask what you use to stop the catapult during a shot. Do you let it stop against a piece of metal like a hard stop? Or another method?

[@PPronounceThis]

It’s not really that clear in the video, but we have a piece of rope attached to the chassis that went up to the center of the catapult arm. I would recommend a metal hard stop above the catapult with mesh wrapped around it to absorb shock better.

[@declancraig4712]

@@PPronounceThis Thank you! We currently use a metal hard stop and we’re wondering if string was better but good to know.

[@parallax654x5]

Dang, we were planning to start an 8 motor drive robot today. Dope Robot. Any specific reasons for the rebuild?

[@PPronounceThis]

We are rebuilding to be five holes, narrower, slightly slower drive speed, and also same side shooter.

[@ethanbayard8284]

@@PPronounceThis keeping the drive train?

[@PPronounceThis]

@@ethanbayard8284 full rebuild with a different ratio and smaller chassis

[@kendallsteele8061]

Did u consider a lever pto? As opposed to a slider

[@CubikArtmosaic]

Are you rebuilding to the same concept/motor dis?

[@PPronounceThis]

Similar. definitely keeping the intake/catapult ratchet.

[@ryanallen1606]

how do you get your discs to not tip over when youre driving? our loading angle is similar and whenever we drive the discs tip over in the cata.

[@PPronounceThis]

If you watch our match video posted also on our KZbin channel you can see that the disks wobble around as well. This is extremely annoying but really you just need to make sure they’re tipped the right way when you shoot.

[@ryanallen1606]

@@PPronounceThis Yo! I had an idea that uses the concept of your energy reducing bar on your intake/cata, would it be okay if I used this?

[@dak5h700]

Why didn't you connect your intake to your roller so you didn't need to use a passive roller?

[@PPronounceThis]

When we are using 8M drive the intake has no motors.

[@WesleyAnfinson-wy9sp]

Ratchet powah

[@Blurky7521]

Im sorry did I just hear 8 motor drive 2 motor intake and 2 motor cata?

[@HippityhoppityGnW]

Pto

[@VexRobotics78116]

Do you have a CAD, just wondering because we are trying to build a similar catapult robot (with limited success). ~ 78116A (England)

[@PPronounceThis]

Unfortunately, we are not going to leak our CAD model, and we would like to encourage teams to potentially take inspiration from us, but not copy our design hole for hole. As far as building, a catapult goes, I would just make sure that your robot is really rigid as catapults put a lot of force on the structure of the robot. This will increase consistency and its overall just a better solution. There is a steep learning curve when designing a catapult so as long as you just keep trying different things you’ll get there eventually.

[@rishabnavadgi3116]

We also have a catapult which is one of the top 10 robots in our district. I would recommend trying to use solid standoffs to hold down the catapult frame with 1-2 other supports up top.

[@leo77774v]

This may sound dumb but what does pto mean I’m knew to this

[@PPronounceThis]

PTO stands for power take off. It allows us to switch two of our motors between drive and other mechanisms.

[@CubikArtmosaic]

Cata ratio/rpm?

[@PPronounceThis]

22 rpm, 36:84, 12:60, 36:84

[@kendallsteele8061]

The 36t is the slip gear right?i had problems with the smaller slip gear but i think it was just build quality bad