Wave Robotics 2826 Mini-bot 1.45 sec!

[Tyler Olds]

Check out Wave Robotics' latest mini-bot design! Shot in real-time HERE (http://www.youtube.com/watch?v=saqvMq8GEkY) and at 420 FPS HERE (http://www.youtube.com/watch?v=s33Yv1uGE3I) or just check out our channel HERE (http://www.youtube.com/waverobotics).

Note: Battery is on the mini-bot; only thing that is tethered is the switch to turn the mini-bot on and off.

Deployment mechanism to be coming soon!

P.S. Sorry about the low res ;) ]

[bearbot]

nice jw is you team using magnets or two small wheels and just a battery

[Tyler Olds]

nice jw is you team using magnets or two small wheels and just a battery

Good question! We are using custom "wheels" with no magnets. Really it just comes down to the physics behind the challenge. What really helped us was understanding the motor power curves, increasing the traction interface to the pole, and having the right amount of applied power to weight ratio for the mini-bot.

[Halliday]

Just wondering, how do you plan to start the minibot for deployment?

[Sunshine]

Sweet !!

[Mr. Van]

What really helped us was understanding the motor power curves, increasing the traction interface to the pole, and having the right amount of applied power to weight ratio for the mini-bot.

How did you provide traction on your custom "wheels"?

-Mr. Van
Coach, Robodox

[trilogy2826]

Mr. Van, I can provide a few hints on the traction material, but don't want to give away the farm quite yet. Plus, what fun would it be if I just told you. ; )

1. The material is 100% legal,
2. The material is not in the Tetrix parts makeup
3. The material has a higher coefficient of friction to steel than rubber (thus is not rubber)
4. The material can be easily found online with the right magic words

The real trick in increasing the traction was making sure we were applying the force to the pole normal to the axis of rotation of the wheel. Our first ten or so protos were a failure (or at least a relative failure) because we were dramatically overthinking the retaining mechanism.


I promise that we will divulge everything at the Wisconsin Regional in week 2. Of Course, by then, everyone will probably have a 1 second minibot and we will be behind the ball.

[Gatlin18]

Did you make your wheels out of Polycarbonate? I'm looking at the list of materials usable on the minibot, and that is the only thing I've seen used as wheels. Not sure about the traction on them, because I don't think anyones ever compared it straight to rubber.

EDIT: Just thought, you could put a nonslip pad (that comes in a roll so it would be easy to put on where the rubber would be of a regular wheel, these still being made of polycarbonate), that would have better traction than rubber.

[trilogy2826]

No Non-slip pad or Polycarb. No aluminum in the wheels either

[penguinfrk]

Inverted surgical tubing? I really have no idea!

This video is going to be the source of inspiration for our minibot team, which is just starting to push 3 seconds.

[Ryan Gordon]

Very impressive, will be interesting to see how it holds up against the competition

[jason701802]

Are you using rolls of electrical tape as wheels? Also, did you remove the standard tetrix gearbox, and if so, what did you replace it with?

[lucoytoa]

Polyurethane wheels

[trilogy2826]

As far as I know, Polyurethane is not on the approved list, so from our view, no, they are not polyurethane

We did try electrical tape and many varieties of heatshrink tubing, but none gripped well enough for our purposes.

The only thing I will comment on the gearbox is that it is so incredibly inefficient that you are losing more than 60% of your potential tractive energy inside this box. This is one of the main reasons that we are seeing so many smoked gearboxes. We have destroyed 3 of them ourselves. They need to be dramatically improved ;)

[trilogy2826]

One major clarification on the timing illustrated in this post: The 1.45 seconds was our fastest recorded time, with our slowest recorded time at 1.67 seconds. The video that was posted was a 1.6 second run. We have good reason to believe that the next proto iteration we are testing tonight should approach the 1.25 second mark.


Anyone that breaks the 1 second mark, please post that it is possible. I know in theory, the math and physics support it, but ... well I don't need to finish the comment.

Right now we are treating the one second mark akin to the sound barrier and X1. We know it should be possible, but we will believe it when we see it.


As for deployment, we have a pretty robust system in place and is easily under 1 second. We will most likely have to tune the "launch" down a bit to prevent destroying our minibot.

[pfreivald]

Will one-second minibots be so light that they don't have enough momentum to depress the switches at the top of the pole? :eek:

Seriously, thouh, great job, guys! We were pretty happy with our sub-three-second minibot, but are constantly looking for upgrades.

Your traction comments are... ...interesting.

[Chris is me]

I'm making the assumption that you guys modified the Tetrix transmissions to remove several stages of inefficient gearing.

However, I still have no idea what magic tractive material you found.

[Bjenks548]

is the back side of electrical tape a legal wheel tread?

[KrazyCarl92]

Non-metallic rope or cord...that could be just about anything that's grippy!

[jacobjlr123]

Now that is a teaser!! Hope to see it and you and sussex

[Mark Holschuh]

Are you guys feeding steroids to your robots again? I didn't see those on the list of approved minibot parts... :D

[Mike Wittman]

The wheels are made from unobtanium which is a string like material that can be converted to just about anything you want including traction on metal wheels and tetrix transmissions.

[metainf]

Hmmmn, non metalic rope/cord...
Nylon!
Could the wheels be covered in nylon rope/cord?
Nice job on the minibot, we have rebuilt ours 3 times already.
Bleh.
But again about the nylon, could that be used?

[pandamonium]

how much does it weigh?

[TEE]

Are you planning on having more than one minibot at competitions, for potential use on your alliance's robots?

[trilogy2826]

Weight is currently at 2.23 lbs including battery and two motors

We have traditionally used nylon as a low coefficient of friction material, especially againt metal. Ours does not contain rope or nylon.

We will be bringing at least 3 to competitions and a spare deployment system that we could "possibly" put on an alliance members bot.

[JesseK]

Forgive my cynical pragmatism: I just don't see the point in gloating about a 1.6 second minibot that doesn't have the battery or switches onboard. On the other hand, the grippy material is a fun teaser; I have an idea but I'd need to test it to see if it's truly grippier than rubber.

[Vikesrock]

Forgive my cynical pragmatism: I just don't see the point in gloating about a 1.6 second minibot that doesn't have the battery or switches onboard.

The battery was on board.


Note: Battery is on the mini-bot; only thing that is tethered is the switch to turn the mini-bot on and off.

Emphasis mine.

[JesseK]

Ah, I see. Bit of foot-in-mouth syndrome this year.

[hobbes20xxx]

Hmm, our team is sort of struggling as far as the mini-bot goes. From that video i have no idea where your motors are...

[Chris is me]

Ah, I see. Bit of foot-in-mouth syndrome this year.

I think you just talked yourself out of borrowing 2826's minibot this year :p

lol, just kidding

[trilogy2826]

Forgive my cynical pragmatism: I just don't see the point in gloating about a 1.6 second minibot that doesn't have the battery or switches onboard. On the other hand, the grippy material is a fun teaser; I have an idea but I'd need to test it to see if it's truly grippier than rubber.

When we did the very first test with this proto, we did not have the battery connected, simply tethered to a battery and switch pack. We were pretty excited when it climbed the pole over 10 tests with min and max times of 0.55 seconds and 0.75 seconds, and the reason the slower times occurred was because we never changed the battery. It was really fun to reverse the motors and see it shoot down the pole at least twice as fast as it climbed

Then... reality set in. We added the boat anchor and it wouldn't move a millimeter let alone climb the pole. The math supported the possibility of this working, but we probably skipped a few days in some past math classes. We found a simple way to increase torque and we were at where the video showed.

All in all, we produced 12 radically different prototypes and 3 iterations of the one you saw in the video. I can guarantee that others have a faster minibot than we do, so by no means are we gloating. We only wanted this post to show everyone that perseverance will pay off in the end. We also wanted to show that Winnovation's inspiring video was not a fake and that the results are repeatable independently. When we meet 1625 at Midwest, I am sure they will have a sub 1 second minibot (but maybe we will too;) )

[orisenak]

cool
is there any links that show it going up at real time speed???

[trilogy2826]

Link to real time video is on the original post.

Now also here (http://www.youtube.com/watch?v=saqvMq8GEkY):

http://www.youtube.com/watch?v=saqvMq8GEkY