2438 Gateway Update Thread

VEX V5 General Discussion VEX Robot Showcase
#1

Hey all. The old design thread title was restrictive and kind of misleading, so I posted a new thread where we can put all of our design updates. Moderators, feel free to delete the old one. Everything in there is reproduced here.

Questions and comments are always welcome. Thanks for reading!

v1.0
http://img64.imageshack.us/img64/4754/img0363ca.jpg
http://img59.imageshack.us/img59/3590/img0364dw.jpg
2438 v1.0 had a spinning intake that brought objects into a powered track, where they were moved around by a conveyor belt with paddles on the track’s underside. The system required a lexan plate roof to provide the downwards force necessary to keep the objects on the conveyor. v1.0 won the McKinley Vexhibition with the help of alliance partners 3008 and 2504.

Intake: Spinning legwheels, powered by one 3-wire motor at 1:1.
Lift: Pivot powered by four 3-wire motors geared at 5:1.
Drive: 6WD powered by four high-speed 393 2-wire motors sprocketed at 1:1.
Capacity: 4 (3 without expanding back), track powered by one 3-wire motor.
Weight: ~14 lbs.
Average Score per Match (working): 20

Video:


http://www.youtube.com/watch?v=RLqqrTJa6ks
http://www.youtube.com/watch?v=zUvTgGRkdf8
http://www.youtube.com/watch?v=ysfQ7n9s7dE
http://www.youtube.com/watch?v=76MTHd3xODo
http://www.youtube.com/watch?v=_FGznn7Xn3s
http://www.youtube.com/watch?v=CXnTURpcE5A
[
v1.1 was the iteration we created for our second tournament of the year, which took place in Hilo. We changed the track entirely to be side-powered, but in a very unique way–see if you can spot it. We also moved over to 4WD in order to save space for the now-larger intake. Unfortunately, we ran out of time to stress-test before the tournament, and the robot had breaker trip problems on the drive because the wiring was suboptimal and the manipulator was heavy. Once we redid the wiring, the robot performed admirably, becoming one of the highest-scoring robots in the tournament and moving into the semifinals with alliance partners 368C and 2439A.

Intake: Spinning legwheels, powered by two 3-wire motors.*
Lift: Pivot powered by four 3-wire motors geared at 5:1.
Drive: 4WD powered by four high-strength 393 2-wire motors sprocketed at 5:7.
Capacity: 5 (3 without expanding back), track powered by two 3-wire motors.
Weight: ~16 lbs.
Average Score per Match (working): 25

Sorry, no videos of this one–we didn’t take any. The East Oahu regional is in four weeks, and a revised version of this robot (fixed for reliability and increased speed) will be in attendance. Hawaii teams, see you there!v1.1http://img838.imageshack.us/img838/3702/imag0339ya.jpg](http://www.youtube.com/watch?v=nRFdS4YtHgg)

#2

http://www.youtube.com/watch?v=RLqqrTJa6ks
http://www.youtube.com/watch?v=zUvTgGRkdf8
http://www.youtube.com/watch?v=ysfQ7n9s7dE
http://www.youtube.com/watch?v=76MTHd3xODo
http://www.youtube.com/watch?v=_FGznn7Xn3s
http://www.youtube.com/watch?v=CXnTURpcE5A
[
v1.1 was the iteration we created for our second tournament of the year, which took place in Hilo. We changed the track entirely to be side-powered, but in a very unique way–see if you can spot it. We also moved over to 4WD in order to save space for the now-larger intake. Unfortunately, we ran out of time to stress-test before the tournament, and the robot had breaker trip problems on the drive because the wiring was suboptimal and the manipulator was heavy. Once we redid the wiring, the robot performed admirably, becoming one of the highest-scoring robots in the tournament and moving into the semifinals with alliance partners 368C and 2439A.

Intake: Spinning legwheels, powered by two 3-wire motors.*
Lift: Pivot powered by four 3-wire motors geared at 5:1.
Drive: 4WD powered by four high-strength 393 2-wire motors sprocketed at 5:7.
Capacity: 5 (3 without expanding back), track powered by two 3-wire motors.
Weight: ~16 lbs.
Average Score per Match (working): 25

Sorry, no videos of this one–we didn’t take any. The East Oahu regional is in four weeks, and a revised version of this robot (fixed for reliability and increased speed) will be in attendance. Hawaii teams, see you there!v1.1http://img838.imageshack.us/img838/3702/imag0339ya.jpg](http://www.youtube.com/watch?v=nRFdS4YtHgg)

How well does your collection mechanism work compared to other collection mechanisms?

#3

Whoa, dude, no need to quote the entire post to ask one question. Anyways, the opening forty seconds of this video show off the intake of v1.0. v1.1 has an intake that is smoother and faster than that. Intake speed is roughly equal to those of the robots in this video.

#4

Interesting conveyor, do you have any videos of it in competition?

#5

This was at the very end of the post. Although there is a video link above your post to iteration 1 in competition.

#6

I saw the iteration 1.0 and his comparison of iteration 1.1 to the robots at the world cup, I wanted to see the 1.1 and how it compares to 1.0. Will wait for a link or the upcoming scrimmage.

#7

1.1 has been sadly disassembled for the construction of 1.2, so unless someone has videos of the Hilo regional it will likely never be seen again. On the plus side, 1.2 should end up using pretty much the exact same manipulator as 1.1 did, so you’ll still get to see it. (Assuming it’s done in a week.)

#8

Nice job! These are very good looking and great performance robots!

#9

for starters nice upgrades they look really good and will probably help you a lot. but is the mechanism that pushes up/down the game elements in your manipulator the HS chain that runs through your manipulator and connects to the leg wheels? dose it work good? also it may just the photo angle but i did not see the poly-carbonate top you had on your manipulator before why did you choose not to use it?

#10

Thank you.

It is far superior to the bottom-mounted conveyor. Basically, because it’s not relying on friction any more, every movement is about three times as quick as it used to be. It’s comparable to AURA’s World Cup robot, though I don’t have it right in front of me, so that could just be nostalgia talking. Anyways, I do really like that mechanism, but it took quite a while to get it up and running.

The picture was taken after we removed the Lexan roof; its services were required elsewhere. We did use it on the robot, though, to prevent stuff falling out the back.

#11
#12

Thank you very much for posting this (and for picking us at the tournament despite our motor problems in qualifications). You were great partners.

I think this video does a great job of showing the strengths and weaknesses of this robot. Because we were rushing to finish it, it had no autonomous. The drive crew had very little time to practice with it, so there were some occasional bad driving moves or coaching decisions (between wasting time pre-doubler, leaving the 30" doubled goal unguarded to go do nothing, trapping our partners in the corner, and missing with at least two objects, that match was not very good). The two sides of the conveyor would sometimes come un-synchronized, which would kick an object out slightly to one side or another, like the barrel that missed at 0:27. That match was also the only time we ever saw an object get stuck in the back of the track, something that we hadn’t fixed because we hadn’t seen it before because we hadn’t tested. On the other hand, it still scored 21 points with 12 objects.

Sorry for my talkativeness, but I feel like the more information we give, the better it can help people critique it, right?

#13

OK. Thanks for the info!

#14

May I ask why the transition from the small c-channels to the large 1x5x1x25 c-channel in the base of the robot?

#15

Update time!

v1.2
http://img526.imageshack.us/img526/5720/imag0362i.jpg
This is the last you’ll see of v1, which was christened 2438C at the recent `Iolani tournament. It had an adventurous run there, falling just short of first seed when a doubler missed its target in the next-to-last match of the day. It ended up fifth seed and was picked by the third seed alliance with partners 2932 and 368. Unfortunately, it blew its drive in quarterfinals and needed repairs. We incorrectly diagnosed the problem (which was in a motor controller rather than in the actual motor), wasted the timeout, and were eliminated. A heartfelt apology to our great alliance partners–you guys were great!

We’ve hit ceiling on this design, and you won’t be seeing any more iterations of v1 at future tournaments (unless something goes seriously wrong). This was a very well-executed robot, robust and efficient, but the design was simply outperformed by v2. The big improvements were in reliability, which is why you see no significant bump in scoring performance (but it worked 40% more often than 1.1, so that’s good). The intake speed on this roller is excellent, but the decrease in score speed caused by adopting a pivot lift rather than a six-bar was not worth the lower center of gravity. Farewell, v1: you served us well!

Intake: Spinning legwheels, 2 2-wire motors
Lift: Pivot with a 5:1 gear ratio and a rubber band assist, 4 2-wire motors
Drive: Back-centered 4WD, 4 HS motors
Capacity: 5 (3 without expanding back), pseudopaddle track linked to intake
Weight: ~14 lbs
Average Score per Match: 26

v2.0
http://img855.imageshack.us/img855/6932/imag0366e.jpg
When another design failed to pan out with two weeks left before the tournament, v2 was born. It draws heavy inspiration from both team 24 and team 720’s designs, which saddened us, but we felt that in this case derivation was a necessary measure. (Rest assured, the 2.1s are going to have some new and cool ideas. You’ll see in two weeks, hopefully.) The score speed on the gravity-dumper robots is really fast!

Anyways, v2 (which competed as 2438B) was a tournament champion after seeding third and being selected by the awesome 1973 robots. It dropped one match, which was lost when a a match load took a weird and unlucky bounce, dropping into the lift and halting intake. That’s what happens when you build a robot in two weeks and have no time to stress-test. Still, it was undefeated in the rest of the tournament.

Intake: Spinning paddles, 2 2-wire motors
Lift: 6-bar with a 5:1 gear ratio and a rubber band assist, 2 HS motors
Drive: Back-centered 4WD, 2 HS motors and 4 2-wire motors geared 3:5
Capacity: 3, slanted polycarbonate track
Weight: ~12 lbs
Average Score per Match: 28

Comments are welcome as always.

#16

v2 looks great! My team has the same general design. Looks like most teams are going to adopt the side rollers with some kind of 6-bar arm. We’ll see. Anyways, great robot (especially since its only 2-weeks old).

#17

Thanks!

We might not be… :wink:

#18

Can you give me a bit more detail of how your “suckers” drop down ? And what causes it to stay in that fixed position before the match . I would really appreciate it .

#19

1973D and 1973E thank you guys for being an awesome alliance partner. We honestly believed you guys should have ranked first, I guess they were just… lucky that tournament (they were building and programming until the last night, had to ditch putting potentiometers and encoders on). :smiley: Our D team was having bad luck as well, with forgetting to lift the gate to some battery problems (let me just mention you guys were great again).

You guys have inspired our A & B team to perform some major remodeling on our robots & strategy, and we thank you for that as well.

#20

Hmmmmm, not from us. :wink:

-Nick