Good Robots

VEX Robotics Competition Discussion VRC > Previous Games
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There seem to be a few general types of robot that are being successful this year. I was wondering what you all thought.

Type 1: Roller/dumper. Probably the best example is 254a. A simple L-shaped basket with some kind of roller that pulls balls into the basket and then dumps them over the back. Typically holds 2-3 medium balls.

Type 2: Flipper/dumper. Lots of robots like this. Some kind of fork or spatula on an arm that flips balls into a basket, which then dumps over the wall. Typically holds five or more medium balls.

Type 3: Belt lift/dumper. Uses either single row or double row of belts lifting balls into a basket which dumps. Good example of this is 2Z from Gladstone in BC. Typically holds five or more medium balls.

Type 4: Ball cage/4-bar link. Uses rollers or belts to pull balls into a cage, which is then lifted in the air using a 4-bar link. The rollers or belts reverse to score. 1107A from Cambie in BC is a great example of this strategy, and they can score small balls into the goals where they are locked up. This could be a game-changer at Worlds in Elimination matches. Typically hold 2-4 medium balls.

Type 5: Catapult/pitcher. Uses stored energy in rotating wheels, latex bands or compressed air to loft one or two medium balls over the wall. 10Z and two robots from Georgia are notably successful catapults (that I’ve seen).

Type 6: Clawbot. Uses a gripper to pick up and score one ball at a time.

A whole lot more approaches than last year! What do you think will be successful at worlds? I can tell you that Exothermics teams have been changing their approaches over the course of the season. As of today, we have two 4 type 1, 2 type 2, 1 type 3, 2 type 5, and one type 2 variant. In November we had more type 2s than anything else.

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This is definitely debatable (in so many ways), but what about a Type 7: Defensive bots? (not just bots with a wall, those specifically designed for purely blocking play like the more recent version of 254A)

Maybe it’s just me, but when I was thinking about this the other day it sorta made sense for me to categorize robots by how they intake and how they spit them out (I don’t want to say dump or drop because, as we all know by now, that’s just not true all the time)

It seems to me every bot is a combination of a couple of these elements.

Intakes

Rollers on a pivoting arm (1,4, and I’d lump 2Z in here because I see it as a variant of the concept.)
[INDENT]Common, mostly because it’s efficient in intaking a large amount of balls in a short amount of time; combined with a fast/lightweight bot, moves incredible amounts of balls. Can double as the dropping system.[/INDENT]
Flipper/Scooper (2)
[INDENT]Usually on dumpers, lifting balls into some kind of basket. Well-designed ones can pickup without stopping (careful driving is needed). Also has an advantage over rollers because things are moved out of the way so the mechanism can operate unimpeded (balls can jam in rollers)[/INDENT]
Ramming (into walls)
[INDENT]Usually on things that simply can’t spare the motors (or space) to have a more dynamic intake (catapult). Works, but imo there’s better ways to intake for most bots.[/INDENT]
Claw
[INDENT]Probably a bit biased here, but not that great. Moving one ball at a time just can’t match a sheer volume of balls. And even then, there’s the positioning of the claw and stuff like that to worry about.

Dumping things doesn’t have as much to say; once balls in the bot it’s pretty straightforward getting it out. Bigger buckets (i.e. bigger dumps) tend to be slower in raising up/dropping the payload so they tend to be blocked more though (721+2Z vs. 12A+12B, epic match) plus, of course, nobody wants to let 12 footballs change sides at the same time. Ever.

I really love how there’s more approaches to this year’s competition than Elevation. Last year, the designs really levelled off once people figured out the double tread thing, and the only real change after that was having another set of treads going through the back so that robots could handle autoloaders. This year, there’s six or seven effective ways to win the game, and it’s a whole lot more interesting in that respect, although it does make it sort of a rock-paper-scissor kind of thing sometimes. One match on Courtenay pitted us and 1107B (catapult) against a wallbot and something else. We could dump over them, and the catapult could aim itself at another part of the field. Game, set, match. I doubt many matches will play out like that at Worlds though.

And thanks for the praise Mr. Tyler; 11 more days to go.

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254a always seems to bring something complex to the table. Their “L” dumper combines a roller based intake with an “L” bucket and pneumatics that add a catapult aspect to their dump. This extra boost lets them throw balls well into the field rather than near the wall. Overall the roller/dumper design has proven to have high capacity but, because of the large buckets, these bots can be a bit sluggish.

I believe 1709a (maybe?) had a nice flipper/dumper/“+” holonomic bot. They were a bit slow due to the “+” holonomic and a large bucket but these guys destroyed their competition. All around the flippers have also done very well but aren’t the quickest of the bunch. The flippers sometimes need to push the playing objects to part of the wall in order to acquire them, some can get under the playing objects with speed alone. The flippers tend to be a bit more mechanically involved, usually the flipper itself is a large part of the bucket that moves where the bucket itself also moves.

These designs actually surprised me. I have seen some belt bots do rather well, but as expected I’ve seen some that jam up, are only able to hold about two medium balls and generally speaking entirely fail. A well designed belt can do well, a poorly designed belt is ASKING for trouble.

Very few teams make use of those goals, but this design can. I like this design quite a bit but it requires lifting a heavy manipulator and it requires a “U” shaped base which may prohibit certain drive-train solutions. With this said, a standard 4w drive can make one of these bots pretty quick and could give this design an edge.

The catapult bots are great fun to watch. Catapults are quick to gather and quick to deliver however the reloading process is where they are slowed down. Also catapults suffer from inaccuracy. Many objects can end up outside the playing field where dumper designs can be sure to score every object almost always. Catapults require more planning and testing as they make use of potential energy. I’ve seen one very successful catapult and at least one unsuccessful copy-cat. Overall this design is quick but can be more inaccurate.

The Eddy factor. For those that don’t know, team 508 classified "Eddy’ as an engineering term meaning: “the simplest design that can score in some way.” Eddy bots have a few universal rules, they typically look like modified square-bots, they typically look weak or easy pickings, yet they surprisingly work well. Why? Well because simple works. Eddy’s can be fast because the’re small and that speed can make up for their lack of capacity. Do not underestimate an Eddy bot.

Combine theres six types of robots with either a four wheel drive, six wheel drive, “+” holonomic drive, “X” holonomic drive or that five omni wheels drive and you have accounted for most of the VRC designs that I have seen so far.

-Cody

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That would be 254Z.

Again, I think that an alliance that is made up of a good scoring robot and a great defensive robot would be very hard to overcome.

5

We call those BLTs – “brave little toasters.”

6

Brave Little Toasters, perfect. :slight_smile:

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lol i have made a lot of brave little toaster toys. my robot is type 4 and you wouldn’t believe how fast it is we have scored up to 8 balls in the first 5-7 seconds of operator control you probably don’t believe me i have no videos :frowning:

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I can say that my robot is none of the above. I am not going to say anything more you will have to see me at worlds to find out :wink:

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8 MEDIUM balls?
or did you just spent your entire autonomous collecting :P?

10

it can hold up to 4 balls then knock the three of the wall then score the four balls then go back for more. 7 medium balls from that but it would get 3 more balls and score them and the first would go in around 7 seconds on the second pic up

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woops forgot to say we don’t collect balls in autonomous we just knock over the 3 footballs on the side and drop one plus the 6 green balls then turns
and ready to get the others in operator control my brother/programmer/driver dose not have a field to make autonomous on so we still have a mildly awesome autonomous mode but we work on it at competitions so at mid Atlantic we hope to pic up and drop some balls

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575’s second robot was a belt-bot-dumper that worked extremely well once they got some electrical problems ironed out. They missed two matches at Gladstone because of these issues. After that, they did great. What made their belts unique is that they used four belts (two inner and two outer) with the outer belts mounted on a pivot so that they could be lifted up to drop jammed balls, although jamming was rare, and brought down to provide tension on the balls being lifted. Having the outer belts on a pivot also meant that the basket was 16x17.5. The team ditched this design for flipper-with-dumper when they decided that there was simply no good way to make the belts faster, and that the whole robot was too heavy.

This is a side view of this robot, it’s on the red alliance and has six wheels: Photo and Video Storage | Photobucket

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254A is not necessarily simply a Type 1 Robot. As someone else said, their pneumatics make them a mix of Type 1 and Type 5. From what I’ve seen, though, this is the most successful design type of all of them.

The best example of this type of robot I’ve seen in Northern California is 254C. Though they are not as noticed as 254A, they are extremely efficient. I disagree with Smartkid because from what I’ve seen, the well-built ones can be fast as well as efficient/have a high storage capcity.

Type 3 Robots tend to be heavy and on the slower side due to the large amount of tank tread they have on their robot, but can be extremely efficient. The only example I’ve seen of this type is 1000A, and while they were efficient, they were pretty slow, and could’ve been beaten by an Type 1/Type 2 robot that was as well-built and had the same storage capcity.

1000B has had this design for a while, in addition to some other robots, but what I’ve noticed is that they’re prone to failure. I think it’s unlikely that there was sloppy building across the board, so my conclusion is that they’re more trouble than they’re worth. One’s efforts would be better invested in dumper bots of Type 1 or Type 2.

As for scoring in the goals, I saw an interesting design last week at Independence High that was solely designed for scoring in the goals. They couldn’t do much else, but if it was compacted little more and added onto a smaller sized robot, it could prove to be very useful, especially at Dallas… though I’m not too sure how that’d work. It would be complicated and might take a while, but if implemented well, I think that it could make the difference in some tight matches in Dallas.

We’ve done some (unsuccessful) experiments with these, and I haven’t seen any in action at competitions. I’ve seen the 1235 twin catapults, but I think that if they found a way to attach an intake, it would make their robot far more efficient, but I’m not sure if it’s feasible or not, because I haven’t seen their designs up close.

I can’t really say anything about these because I haven’t seen any in action, but they seem overly simplified and are clearly no match for something on the level of 254A.

Overall, the majority of the good robots seem to be of Type 1 or 2 (though, of course, there are good robots of each type)… what do you guys think?

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My opinion is that driver skill is as if not more important than the robot itself. I’ve seen robots that are little more than a protobot with a modified arm do extremely well with good driving compared to some of the higher level robots.

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Agreed. But it’s unlikely that anyone would win without excelling at both driving and design (which, of course, you would know!), unless maybe they’re a third pick maybe.

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1000D has had a solid and reliable “type 2” robot.

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Rick TYler, that is quite a cool collector! Definitely not what I had in mind. I agree that another design might be better but I have to hand it to that team, nice design.

I totally disagree with anyone who thinks a problem cannot be solved in an “overly simplified” way. The simplest solution is often the best, the ONLY factor that really comes into play is speed. If a simple design can be made to score quickly, coupled with a good driver, you have a recipe for success.

I want to comment on PTD’s progress but unfortunately I really can’t. Everyone will just have to wait until about two days before worlds :smiley:

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i think my robot is a lot better than the way type 4 robots are considered by most of you but how is team 1000B prone to failure they looked pretty good in a couple videos i saw.

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SmartKid, having the simplest solution to a problem is not always the best one. If you put a fast clawbot against a robot the caliber of 254A, the clawbot won’t stand a chance.

Rhys Jones, I wasn’t calling 1000B in particular prone to failure - of this design type, they’re the best I’ve seen here in Northern California. I was saying that robots of that type that I’ve seen here in Northern California are generally prone to failure. I haven’t seen your robot in action, so I can’t comment.

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I personally guarantee you that I could build a claw type robot that grabs one medium ball at a time or a couple small balls that could keep up with 254A’s CURRENT design (I wouldn’t put it past them to completely redesign before worlds :rolleyes:). Keep in mind, my previous team, 508, has had many encounters with 254A and were one of their picks at the 2008-2009 world championship.

Here’s what I would do, an EXTREMELY light “X” holonomic, 5:1 gearing on the base using the 4" omni’s, PID control to keep some form of control, 4-bar linkage meaning the arm is always parallel to the ground, a custom claw thats shaped to the football, potentiometer on the arm so the robot can automatically go to the ground on a button push, limit switch inside the claw that triggers when I push the claw against a medium ball, it would clench the football, another limit switch would confirm that we got a ball or, if we didn’t it would release the claw. If a medium ball was captured the arm would auto raise, about three seconds later the ridiculously speedy holonomic would be ready to drop the ball. I’d like to call this a super Eddy, or a mac daddy version of this:

https://vexforum.com/gallery/files/4/1/4/1/cs_05.jpg
SUCH a sweet render, yet it seems old now. I can do so much better now…

Now, I completely agree, a balance of speed and capacity is the winner here. I just want teams to realize that all of these designs have plenty of potential and that, even in a more complex design, the simplest way to pull it off is often the most reliable. The idea is to start thinking like engineers, take reliability and complexity into consideration.

-Cody

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