pic: Team 971 Presents: Mammoth
 

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Intake isn't fast enough, also doesn't have enough control loops.

Just kidding, great looking bot. Excited to see it play this weekend!

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971 is the master of the intake.

Can't wait for this weekend!

-Mike

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This thing will win regionals. Yes, that is plural.

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This is a gorgeous machine. Can't wait to watch it on the field.

-Nick

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Really enjoy the use of the intake to catch/pickup bouncing balls. It's a weird problem to solve, but you make it look effortless. Also, the over the back shot is so fun to watch.

And a question, just to satisfy my own curiosity - the hall-effect sensors on the Claw's pivot, is it safe to assume that each one of them corresponds to some unique position of the claw? Is there any reason for doing this sort of setup over an absolute encoder or similar sensor? Reliability? Cost? Simplicity?

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The separate upper and lower jaw is absolutely brilliant. Your programmers must have had fun with all those possibilities.

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Amazing machine, can't wait to watch it in action!

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Big fan of the spinning lower forks to help center the ball.

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The motorized prongs are beautiful.

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It's cool to see the progress of your robot based on the amount of 2x4's and pools noodles attached to the top of our 2013 drive base. :p

Great job everyone on 971, this looks like an absolute beast of a machine. I look forward to playing together at SVR.

Re: pic: Team 971 Presents: Mammoth
 

Many thanks. We're really proud of this design. Its something that we picked up on rather early and found it worked really well. The nice thing is that it allows us to center the ball without having the intake stick far out of the robot. In this year's wide open game, we felt it was necessary to keep things inside the frame as much as possible. We get a large intake width without having a large intake sticking out of the robot. It was difficult to package, but we are proud of the result. We are very excited to see how it does at Sacramento and SVR.

Yes. It is really nice how we are able to use the full range of the claw, and this comes with the programmability of the robot. Austin can likely fill you in more in this area. We love how we can use both sides of the intake to grab the ball and shoot. We hope this allows for more flexible gameplay and will allow us to explore a wide variety of in-game strategies.

We have 3 hall effect sensors and 1 encoder for each jaw. The hall effects are for zeroing. The one in the middle zeros the claw and the top and bottom hall effects set a software limit for each side of the claw.

Re: pic: Team 971 Presents: Mammoth
 

Forget the flashy claw, take the bumpers off and show us some close ups of that frame design =)

I've been a huge fan of 971's fabrication techniques ever since I started paying close attention to your designs back in 2012. If you can post any amount of parts photos sometime this season, I'd be grateful.

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This is a great looking robot.
We hope to see you guys in St. Louis!!

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I was wondering when someone would mention that :) .

I'll see what I can find. For those who can't see it up close in person, we'll likely post some pictures throughout the season, and make more public at by the season's end. The drivetrain is a result of 4+ years of iteration, and we tried to pay even more attention to detail. So far, we like the result.

Thanks! You guys are looking good too. Good luck at your competitions as well.

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What are all the prongs and wheels in the intake powered by?

Super cool design! I really hope I can see it at IRI or something.

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Centering "Tusks" are each powered by 1 AndyMark. Top claw has 2 RS 550s. Shooter is 2 RS 550s.

Re: pic: Team 971 Presents: Mammoth
 

I like the "jaws of not-death" intake. Very cool.
I also like the versatility (is that the word I want?) of the shooter, able to pick up and shoot in the opposite direction with little driving.

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Wow that is really sweet design. The whole time I was watching the video I was like "this robot has an uncanny ability to center the ball". I had to read the comments to find out why :P, I can see that making a big difference in competition.

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Very cool machine! I think this is the most impressive bot posted so far in terms of ingenuity in the design approach and execution. The two independent moving arms that make up the grabber are a bold design decision that I don't think many teams would have attempted to pull off, if they even came up with the concept to begin with.

And belts everywhere!

I hope you make it to St. Louis, I want to check this out in person.

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I love this robot already. One of the best intakes so far. Was the non-rectangular frame designed to accommodate the superstructure, or was there another reason for the slight bulge?

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Gorgeous machine! :D. I love those round bumpers! They stand out :D

What is the range, accuracy, etc.?

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The octagonal drivebase was a concept that we played with in CAD during the offseason. One of the largest benefits of the octagonal drive base is that it increase our support base, which is especially helpful when our Cog ended up being a bit higher than we would have liked.

We do love those belts. We did have to compromise and include a few chains on out claws and the shooter because the math didn't work out :(

We have not really tested anything past the white zone because we did not see any shot beyond that point as extremely useful. As for the accuracy, I would put us at 90%-95%, but Davis will be a much better tell of that.

Re: pic: Team 971 Presents: Mammoth
 

So cool! The belt to chain reduction is really neat. I would also love to see close ups of the robot.

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Yeah I think Austin may have left out a control loop on one of the muffin fans.... I'll keep you posted.

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But how can you be sure that your drive motors are all cooled in exactly the same way without temperature PID?

From the bits and pieces I saw of this robot, I never appreciated until now how awesome this design could be. Congratulations guys, this guy is truly a technological marvel. Now, the only thing it's missing is the drum shifter...

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Hey, we have to leave something for next year ;) . Though those transmissions certainly have a lot of parts. Not always feasible for a 6 week long build season.
Good luck at Davis.

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Fantastic design. I'll join the praise of that intake-- it really looks like the best I've seen yet.

I'll also join in hoping you guys release olenty of pictures. Such excellent design ought to be shown off!

Do you have any sort of locking on your rotation? If not, what motors are you using for that?

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Rotation of the arms or rotation of the intake?

I answered the intake in a previous post, so I'm guessing you mean the arms.

Each jaw is powered by a CIM. The belts at the back along the A frame each go to a gear box. We put the motors down low for weight/COG concerns. We put another reduction up higher on the A frame. We put control loops on the jaws.

We will post some pictures at some point. Since we'll be a competition, we likely won't be able to until after this weekend. The plan is to have all pictures public by the end of the season.

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Yeah, I meant the entire shooter assembly rotation. Thank you for answering my questions, and best of luck this season!

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Thanks, Good luck to your team as well. It might be a challenge to answer them all with our competition starting, but if anyone has any questions feel free to ask. For those coming to Davis be sure to stop by the pit to take a look.

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Wow this robot looks really nice! I love the fact that it could shoot at nearly any angle, making it a very tough robot to defend. Can't wait to see it play this weekend! Good Luck!!

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A video of the match we got knocked down but got right back up.
To quote the announcer(1:05):"This is what happens when you cross the Mammoth, the Mammoth WINS"

https://www.youtube.com/watch?v=XwmP...e_gdata_player

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I am a little sad that I did not get to witness that in person. My first thought after seeing you guys get back up was WOW that was so fast, a blink and you miss it moment! Getting back up after a fall is a legendary event for any team!:ahh:

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i like the chassis shape

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It was truly awe inspiring to see this guy compete at Davis. It seems like 971 just hit it out of the park with this one. Everything about this machine is extremely fast, accurate and overpowered. I can't wait to see it in action (and play with/against it) at SVR.

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Thanks Tytus. We took some inspiration from your 2005 frame.

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Sorry I never had an opportunity to swing by your pit and get a really good tour of your robot, although I did do the inspection on it, there were a few details that didn't need to look at to pass your inspection, but would love to know :D

I know you are running 4 CIM drive, 2 per side through WCP gear boxes with custom side plates. What are your final total reductions to the wheels for low and high gear?

Were all three wheels on a side in line, or was the center offset outward?

Re: pic: Team 971 Presents: Mammoth
 

We are geared for 9 and 17fps based on a 5500RPM free speed.

The wheels are staggared so the center wheels are at the outside (pretty much like http://www.chiefdelphi.com/forums/sh...ad.php?t=38184 but with the center wheel directly driven and belts instead of chains going to the outer wheels, and all in sheet metal). We will try to get some more photos up once things calm down.

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After getting the opportunity to play two hard fought matches against this bot, I was absolutely awestruck at how consistent and quick this robot was. Defense against it is pointless. Truly, you guys have engineered an excellent machine.

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Thank you! Those matches were great to watch. You guys really gave it your all. Defense may not have stopped us, but it certainly slowed us down. We put a lot of priority on designing drivetrains that can avoid defense and train our drivers to get around tough d. But thank you for the praise of our robot. The team worked very hard this year and we are pleased with the result.

599 built a great machine this year. I was impressed how good you guys were at assisting at Davis and Inland Empire. In a year where many teams went for shooting, you guys built a well rounded robot that could play the point and put in a few shots yourselves. It was great having you guys make the trip to Davis this year.

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Could you go into detail on how you designed your drivetrain to avoid defense?

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The drivetrain has been continuously iterated for the last 6+ years. Each year we try to make things better, cleaner, and more efficient. A lot of what we do makes the drivetrain easier to maintain and service, and other changes help increase the general mobility of the drivetrain, which helps with offense and defense.

This year, with the wider wheelbase, we've been able to reduce the negative effects of a high cg. This certainly helps against defense. We've also gone with the conventional 4 CIMs, a change from last year, when we blew breakers more often than we cared for. This helps us not die as a result of a hard pushing match. On the maintenance side, we've also done more research into how to properly tension belts to help them last longer in competition. There are some other small benefits here and there. I encourage you to stop by our pit at SVR to take a look. It's always easier to show rather than tell, and nothing beats the real thing.