Large ball intake roller design

Hello everybody, l’m Martin and I just joined this vex team this year. So far we’ve been to two competitions and my robot were complete faliures… But this time I actually calmed down and looked at some good bots, and so far I have crambled out my first official toss up bot…
Some information about my bot:
Base: 4 motor 1:1 tank drive suspended base
Lift: 4 motor 1:5 6 bar lift
Intake: 2 motor 18 tooth gear with middle belt inserts
Right now it handles buckies very well. I am still thinking about adding large ball manipulation, but not sure which design is the best. What do your team use for beach ball roller? I’ve seen shafts or stand off mounting for the upper roller, and all types of rubber for intake. What do your team favor?
It is getting late and I’ll post pictures tomorrow. Thanks for viewing.

Well what’s worked really well for me and a whole bunch of other teams are “ruiqrollers” (I swear I didn’t coin the name). It’s basically 2 30 tooth sprockets with chain and 4 sets of 3 rubber tank treads. Then I wrap rubber bands around the outside and secure them with rubber bands that wrap around the sets of rubber treads, making a hash mark you might have seen a bunch. Off the top of my head, I know that 4252A, 21B, 21D, 2059A (me), 254A are using them. Of course, there is a bit of tuning involved and they require a very special kind of intake mounting, but so far the fastest I’ve seen is intaking a large ball fully in about half a second.

We like the small rubber wheels as large ball intakes. Spaced correctly, they work really well. Just mount them above the Buckyball intake, on the same axle. Simple and effective.

We have our rollers set up on stand-offs, because then we get two points of attachment and not just one.

Here’s a picture:

https://vexforum.com/gallery/showimage.php?i=6063&catid=newimages

Big Ball rollers

Thanks everybody. These are all delightful suggestions. I’ll try them and get prepared for our next event, which is next Saturday. Also we just recently bought some rubber joints, has anybody ever experimented with them? They are really flexible and seem to grip the large ball well.

What I am thinking of trying for our’s is a forklift type system. I.e. two shafts or long pieces that go down to pick it up and turn in/up to move it onto the robot.

Yes, I have considered about that. But since I am not quite good at driving, and my team has only one experienced driver, we are really trying to keep things as simple as possible. A fork intake for large balls requires pneumatics. Also since we use a six bar lift, it will be a bit difficult for us to apply that idea on our lift. But I’ll keep that in mind, since there are successful combined designs of fork intake and catapult. Thanks.

I don’t see why pneumatics are needed? We haven’t built it yet, but plan to use just a 393 motor. It might be tricky with a 6 bar, though.

There is never really a definitive solution, so do whatever works best for you.

As far as the forklift is concerned, what I was thinking of doing at the beginning of the year was having something off the front of your intakes that could be deployed by rubber bands at the start of the match. These things off the front could really just be something like 1x25 pieces at a set width (although you would probably want something stronger). If you raised your lift, these devices would flip down and just be in front of your robot. You could then simply get under the big ball and pick it up. It would be like picking up a ball with a triangle.

We ended up scrapping this idea though once we saw the side rollers. We have a gear wrapped in rubber bands like what android was saying. Side rollers are truly a great design and based off your description of your robot, I would say these would work well with your design and be a quick solution. However, it is all up to you.

So that’s my two bits. Good luck this year!

Yeah man, I too hate to touch pneumatics… But unfortunately I’ve already used all ten motors, so. Not saying that pneumatics is not cool. Since we only have one person who knows pneumatics really well, and we don’t meet very often, I’m usually not allowed to use any pneumatics since I’m a first year vex person… Although I have read everything.

Thanks so much for your idea. Right now I am using stand offs and rubber joints to experiment. But my structure is not that solid, so a large ball does bend my intake basket. I’ll continue to experiment.
Also your design sounds really innovative… At the beginning of the year I was planning for an omni functional scissors lift bot, just like your first idea. But I learned painfully that things should be kept as simple and functional as possible, because my scissors lifts never lifted up… Even during the competition…

Ya for sure. So wait what is your current problem? Your standoffs bend?

Thanks. Ya it’s tough to make scissor lifts. We learned that the hard way too. We were a new team and didn’t know much about lifts and we tried a few… Ya…

You see my intake rollers are being squeezed so far apart after taking in one large ball that they cannot effectively hold buckies anymore. Maybe shortening the stand offs will solve the issue. Well I mean everyone knows it works, and it can be awesome, only if some hard tuning work is done.
By the way, when is your next competition? What is your team number?

From their profile, 3860E.

Hm. So what holds the intakes at Bucky position? It sounds like your problem could be solved with maybe some rubber bands. You can see our design on our Instagram page if you would like. They do really well with either size. They also flip down at the start of the match which is cool.

As Kevin said, we are 3860E. We are a California team from Orange County. Our next competition is this Saturday so that wil be interesting. Gotta get our code workng but we are having some issues with it and I can’t figure it out.

I recently tried to shorten the stand off size and that worked out really well. But still, it hurts my heart watching the large ball squeeze apart my intakes again and again…
Based on your description we have similar bots. Our intake also flips down at the beginng. Cool hun?
Our next event is also this Saturday, against Gwinette school of mathematics and science, the third ranking high school in the nation. You’ve probably heard of them. They used to be FCR world champions and are really good at vex also. So good luck I guess, we really hope to meet you in the worlds.

Programming issues? Please describe it. I am a programmer and I think I may help. Codes are easier than structure. They can be fixed instantly, if you know how.

Ya it does sounds similar. So wait, are your intakes simply held in place by a screw? What we have is a c-channel with our intake attached by an axle to our housing. It allows for motion sideways and returns to position easily by just having rubber bands on either side to hold it in a neutral position. If you look on instagram at buy_n_large, you can see our intakes. I can also send you better pictures elsewhere. It sounds like your intakes have no way of returning to their neutral position though which could be your problem.

Oh and good luck with that… Sounds difficult.

Oh see I am the opposite. I can find solutions to a structural problem way faster than I can solve programming issues. This is my first time programming so I am struggling. We use EasyC and I get most of that stuff but the actual code language and such I struggle with. I can copy someone else and apply it in a limited way. However I don’t understand what it says to the computer so I just stumble blindly hoping something works if I try something new. And well… we have a few problems.

  1. We want our turning to be at the center of our robot. We have the bumpy wheels as our back wheels and omnis for our front wheels so we do not get pushed around like if we switched to all omnis. However, now we swing turn instead of center turn so we turn pretty slowly because we have to reposition so freaking much. We are trying to find a way to write a code to do this for arcade drive but are struggling with it.
  2. We are using a potentiometer choose between five different programs. It is almost all written but when I try running the programs and choose a program using the potentiometer, a single program runs over and over again. It does intakes out, lift up, intakes in, intakes out. It then repeats this cycle over and over.
  3. I also want to use a line follower but have no idea how to do this. I incorporated it into my current programming but I am not sure if it’s correct.

Basically… I struggle with programming beyond a certain point. I can build a lot of things but can’t get the programming down. It gets interesting to say the least.

http://www.mediafire.com/download/sopcnjqm1bpjpp2/Buy_N’_Large.ECPX
Here is the posted program. I’m not sure if it will work but there it is.