14-03-2012 20:30

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Wow. Wow wow wow wow wow. This thing is just AWESOME! I expect no less from former world champions, but this is still just awesome! Great job 971! You always make some of the best machines in FIRST each year, and this year is no different!

See you in SVR!

P.S. Robot unveil video soon?

14-03-2012 20:34

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

We also worked to make new wheels this season, to complement the new drivetrain.

Tread is attached via zipties.
Wheels measure around 2 inch wide and 3.5 inch tall w/ tread.

Thank you to RC for machining these. They turned out great (so far).

14-03-2012 20:41

Nuttyman54

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Not for Sacramento, unfortunately. I'll try to do a pre-SVR or pre-Champs video. They only finally captured footage for a video at last night's driver practice, but they weren't able to get it to me in time to edit it down. I still don't have it (I still haven't even seen this thing run in at full capacity!). If there's no webcast of Davis, I'll make sure we release something before SVR.

14-03-2012 21:11

Akash Rastogi

Re: pic: FRC971 Spartan Robotics Presents: Renegade

That is such a clean and beautiful design. You folks always inspire me with your sheetmetal work, and this is no different.

A couple questions:
1. That gearbox orientation looks really nice, would you mind posting a picture of the gearbox/internals of your drive?

2. What OD and ID tubing is that on your structure and why did you use that this year?

3. Any issues with balls jamming in the hopper/conveyor?

4. The entire robot looks incredibly light, what was your final weight and what was your method of conserving weight? How much pocketing went into your structure and what material thickness is used around the whole bot?

Looks incredible, thank you for such a beautiful machine. Best of luck in Sacramento.

14-03-2012 21:16

Gray Adams

Re: pic: FRC971 Spartan Robotics Presents: Renegade

At one point during our season I was thinking about an under the bumper intake based on all the reports of balls getting stuck under robots, but I wish I thought more about an over bumper design. That would leave so much more space for electronics and simplify the frame.

14-03-2012 21:18

James Kuszmaul

Re: pic: FRC971 Spartan Robotics Presents: Renegade

1) Not sure where to find pictures of it (there probably are some lying around somewhere), but basically we have a 2-speed transmission using compact pistons from Bimba. It is a two-stage transmision, so it is relatively small, and we were able to orient the CIMs such that they are over the center wheel, out of the way of the electronics.

2) It is 1.5" OD 1/32" wall tubing. We are using it because it is rigid and light.

3) Seems to be working reasonably well. I haven't been at the more recent drivers practices, and I usually don't stay very late, so I can't say for sure.

14-03-2012 21:25

Re: pic: FRC971 Spartan Robotics Presents: Renegade

The recent driver practices have shown the robot works excellently! 971 is going to be a strong contender at SAC and SVR. IMO It will win them both, as the alliance captain.

http://www.youtube.com/watch?v=KS3n9...6fFAAAAAAAAOAA

http://www.youtube.com/watch?v=rK2et...47FAAAAAAAAPAA

14-03-2012 21:32

BJC

Re: pic: FRC971 Spartan Robotics Presents: Renegade

I really like the way this robot serializes balls, I'm going to have to keep that in mind for future games.. and the rest of the robot is pretty awesome as well.

Good Luck this year!
Regards, Bryan

14-03-2012 21:33

rcmolloy

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Evan,

Saw this beauty a few weeks ago and I really like what you guys did. Scott seemed very excited about being behind the sticks yet again and I am sure he will go out with a bang this year. Can't wait to hear how you preform this week in Sacramento! Good luck!

14-03-2012 21:53

Nuttyman54

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Thanks for the compliments Akash, the team is really proud of this one. This is the best picture of the transmission I could dig up is here.

There may be some better pictures that surface later, but the whole thing is buttoned up pretty tight, so it's a little hard to see what all is going on inside.

I don't know the final weight offhand (one of the students can probably weigh in on this), but this is a nice picture of our driver, Scott, holding up the frame with one hand.

14-03-2012 22:04

Dan_Karol

Re: pic: FRC971 Spartan Robotics Presents: Renegade

That is one good looking, and sounding, robot. I really like the speed and control you appear to have in the driving videos.

good luck at your competition.

14-03-2012 23:05

tzjin

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Elegant indeed! Everything is super streamlined, though I'm a tad confused about why you feel a need to cool your CIM's that much. Your new wheel design looks really great as well; zipties make for a pretty nifty way to replace tread.

I look forward to seeing you guys at SVR! It's going to be a fun year competition

14-03-2012 23:16

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Same!

We cooled the CIMs in a similar manner last year. It helps us practice longer and drive longer, really. The motors get quite hot. The way our driver drives, you would want fans on the CIMs.

here's a link to last year's discussion
http://www.chiefdelphi.com/forums/sh...8&postcount=18

The extended runtime is useful when we have a high match turnaround (practice rounds, elims, etc)

14-03-2012 23:32

Nuttyman54

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Edit: See Kevin's comments above.

The team noticed in 2010 (the first year we ran with these speeds on the driveline) that during the quick turnarounds in eliminations, the motors started to get quite hot, and became much less efficient. I believe they were noticing battery voltage drops towards the end of every match. The driveteam took to fanning the motors between each match. They added the fans after the season, and saw a measurable improvement, especially at demos. Our robot last year used the fans as well, and they feel it's been very beneficial. Somewhere on CD is another post explaining this (by either Austin Schuh or Scott Bahl, IIRC).

I think that's all correct. One of the students could probably answer this better, but I think they're all busy packing and driving to Sacramento right now. I'm sure they'll add more detail later.

As a long distance mentor, I don't get involved in all the details of the robot, although I do know most of it. I've challenged the students this year that by the time they get to Championships (the only tournament I can attend with them) that they all know more about the robot than I do. Most of them are already there .

14-03-2012 23:42

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Here's a link to Austin's post last year regarding the fans.

http://www.chiefdelphi.com/forums/sh...8&postcount=18

When turnaround time is faster during matches (practice rounds, elims, etc) the fans have their largest effect.

14-03-2012 23:55

DampRobot

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Wow, that's a well done transmission! How did you mount the two gears to the CIM? Did you use the AM 8mm to Hex adapters, or broach your own gears? That's certainly a elegant way to get shifting with minimal complexity. By the way, are the center wheels direct driven?

14-03-2012 23:57

Re: pic: FRC971 Spartan Robotics Presents: Renegade

How does the belt drive work for you? Was it hard to do? If so, was it worth the difficulty?

15-03-2012 00:05

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

We'll see how it holds up at Davis. It has been working pretty well thus far after the drivetrain was tuned.
The timing belt drivetrain is nice, but it's best to run force calculations to see how it'll hold up. Belt doesn't stretch like chain does, and its quieter and a bit more efficient. It is also lighter. This, coupled with the fact that we have 2 inch wheel means we should be able to get to where we want to go on the field.
The extra traction is useful going up the bridge.

15-03-2012 00:25

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

I think you realized this already, but we put in a horizontal conveyer to help sort the balls. Since we were going with ~24 in intake, we needed a way to rapidly get the balls into a column/row/whatever. Once organized, we can pretty easily get the balls into the tower. The vertical belt then runs at the same time as the shooter wheel, and presto, we shoot (and hopefully score).

Below is a picture of the conveyor.



The team spent several days prototyping this. Inevitably, a ball would get stuck somewhere. We configured it with the intake, then make sure we had accurate measurements in the CAD that were the same as the working prototype. Since it was such a key part of our game, we spent a lot of time on this.

15-03-2012 07:42

James Kuszmaul

Re: pic: FRC971 Spartan Robotics Presents: Renegade

We got a shaft custom machined to press onto the CIMs.
The transmission assembly is detachable, and it outputs in a 15 tooth gear which meshes with a 50 tooth gear which is on the same axle as the center wheel.

15-03-2012 08:35

Adam Freeman

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Another awesome machine!

As always you guys play so fast, its amazing. I am sure your drivers will be practiced up and ready to go.

I really like the horizontal belt system to push the balls over and line them up. Really cool way of solving the jamming problem.

I am really happy to see you are registered for the Championships this year. You had such a great robot last year, I think it would have been a big factor in the elims if you could have qualified for Champs.

Good luck this weekend.

15-03-2012 08:58

nlknauss

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Great looking robot and design process you all seemed to follow. After seeing this robot and others from CA it makes me want to take a trip out to visit the regionals sometime. Thank you for sharing the details of your machine with us! Good luck in competition.

Nate

16-03-2012 09:35

Sh1ine

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Very nice robot.

We also use belts for our drive train. This is our second year using them and as for a a skid steer type drive train is concerned I do not think we will ever go back. We use live axles in our system. It seems like you are using a dead axle system with the sprockets machined directly into your wheels (very cool). I would love to see a up close and personal view of how your power transmission works.

18-03-2012 16:57

AlecMataloni

Re: pic: FRC971 Spartan Robotics Presents: Renegade

First of all, Congrats on the win at Sacramento. I'm glad to see you guys coming to the championship this year. I really wish I had seen 971 at St. Louis last year.

Second, I'm curious about the pistons you're using to shift. I've never seen anything like that! How reliable are the "Pancake" pistons? Are there any drawbacks to using them, compared to the standard actuator on an AM supershifter? It looks like they save quite a bit of space and weight. Also, where are they for sale?

18-03-2012 17:02

ttldomination

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Vids are private?

Would love to see this thing in action.

- Sunny G.

18-03-2012 17:10

Re: pic: FRC971 Spartan Robotics Presents: Renegade

I just found them on youtube one day while searching for robot things, and they were public then. Looks like they're private now.

You can probably find videos of the robot in matches at the SAC regional on youtube, or from the SAC regional thread, where someone may have posted links.

18-03-2012 17:18

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

I can talk to people to see if we can get some videos back up. We hope to make some sort of video compilation to send out.

Stay tuned.

18-03-2012 17:38

Cory

Re: pic: FRC971 Spartan Robotics Presents: Renegade

We first used the pancake cylinders in 2010, with the 3 position variety for our PTO, due to the relaxed pneumatic rules. I believe we were the first team to use the flat cylinder line from Bimba.

We used the 2 position ones last year and this year.

They're no more or less reliable than the standard Bimba line of cylinders. They do require different fittings, since they are so small, and must be face mounted.

18-03-2012 17:48

AlecMataloni

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Thank you for the information! Do you know the part numbers for the cylinders and the fittings offhand?

18-03-2012 17:53

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Sprockets (or pulleys I should say, for this is timing belt) are not machined directly on. They are locktighted on the wheel and obtained from SDP-SI. Directly machining those pulleys would take too much out of our resources.

18-03-2012 20:15

James Kuszmaul

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Check here. We used a .313 long stroke, and I can't remember what bore size we have off the top of my head. Probably 9/16 or 3/4.

18-03-2012 20:35

NickCrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Here's a photo of our Robot competing at the Sacramento Regional. As you can see, we made a few changes in between taking our reveal shot and competing at the competition.

We hope to make some improvements and be even better at SVR.

27-03-2012 14:36

roystur44

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Take a look at this short video


http://www.youtube.com/watch?v=5aYv5RF2Arg

27-03-2012 14:43

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Man, Renegade looks better and better by the video. That's some of the fastest 3 point shooting I've seen. I'm hoping we get to play with 971 in a few of our matches at SVR. I can see this robot going right to the top.

27-03-2012 14:55

Jared Russell

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Some interesting background shots there

Great robot!

27-03-2012 15:31

BJC

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Hmmm, 4:57 and 6:04 were pretty unexpected, but I guess they are unveiling week 5 anyways. Looks like a narrow robot with a pretty slick over the bumper collector and a high shooter (probably turreted) Sweet..

Edit: narrow because the fender sticks out 38ish inches.

27-03-2012 15:36

Re: pic: FRC971 Spartan Robotics Presents: Renegade

How do you get that from the video? I've watched those segments about 20 times myself, and though I see bits of it, I can't tell too much from it.

27-03-2012 16:29

Tom Bottiglieri

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Yes, Yes, No.

27-03-2012 22:09

BJC

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Not turreted? well I suspect you wouldn't really need it anyways (If that is indeed what you are saying no to.) Good luck at your first competition this year.

Regards, Bryan

22-04-2012 14:29

roystur44

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Here's a little video of practice for Champs:

Shooting practice:

http://www.youtube.com/watch?v=kTVE8c_mgoI


Behind the glass:
http://www.youtube.com/watch?v=p32DlVbJpFw

22-04-2012 19:09

Mark Sheridan

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Whoa! That is some great accuracy! Looks to me 100%?

22-04-2012 19:14

Nuttyman54

Re: pic: FRC971 Spartan Robotics Presents: Renegade

That was one of our best runs, but we have been hitting 90%+ over the past few days. There is also no camera tracking running in that video, that's pure video feedback to the driver station, and Scott doing what he does best. There may be camera tracking in St. Louis, which could further reduce the cycle time.

22-04-2012 19:14

Siri

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Awesome shooting! How do you like the steering wheel for driving control? And is it just the wheel or are the other buttons/pedals/something involved?

22-04-2012 19:18

Jared Russell

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Given this team's history (and programming mentors), I am guessing that this is their driving arrangement ("Cheesy Drive"):

1. A wheel (you can also use the X axis of a joystick) for turning
2. A throttle
3. A quick turn button

When you are not holding down the quick turn button, the wheel and throttle let you control the bot like a car (in other words, constant radius turns independent of your throttle power, which is hard to do with arcade or tank setups).

When you hold down quick turn, you can turn in place (the wheel becomes like a standard X axis in an arcade drive).

But again, just a guess

22-04-2012 19:18

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Same question. To add on, do you feel there are any advantages to using the steering wheel controller? (User intuitiveness, just feels easier/right to use, etc?)

22-04-2012 19:42

Nuttyman54

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Austin can give a more accurate answer than I, but I believe we are running a version of "Cheesy Drive"

At high speeds, your rate of turn is very sensitive to small disturbances in drive side speeds, so holding a good line with tank sticks gets increasingly difficult as your drive speed goes up. By letting the computer take care of the exact speeds and feeding the system a turning radius and speed, high speed control becomes much easier. It also allows you to scale the steering response based on your throttle level, although I don't know if we do that or not.

The quick-turn button allows a more traditional steering scheme for in-place turns. We've been using a steering wheel setup since 2006 and it's served us really well. It's just the wheel and a joystick for throttle control, as Jared surmised.

22-04-2012 19:45

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Thanks. Just for reference, do you know which steering wheel controller you use?

22-04-2012 20:19

JV2073

Re: pic: FRC971 Spartan Robotics Presents: Renegade

Good Job at the Sacrmento and SV Regionals. You were amazing and we hope to see you in go far in national.
-Best of luck team 2073

22-04-2012 20:49

kevincrispie

Re: pic: FRC971 Spartan Robotics Presents: Renegade

I believe the one we are using at the moment is a Ferrari Thrustmaster wheel. We've used a few different ones in the past, but they weren't as robust. The wheel needs to be auto-centering one way or another, whether that be by design or stringing surgical tubing inside the wheel. However, its much better to have it bought as auto-centering. It less work to convert over.