Team Driven 1730 Reveal
 

Here it is. Ask any questions you want on here, ill do my best to answer as clearly as I can.

http://www.youtube.com/watch?v=sEVkl8V7Q9g&sns=em

Enjoy

Re: Team Driven 1730 Reveal
 

Great job. Love the sideways robot action. So happy you will be joining us at Razorback!

Re: Team Driven 1730 Reveal
 

I can't wait. This will be the second year in a row we have attended a brand new regional. It's going to be a lot of fun. Quick question. Are the pits going to be in the same building/ arena as the field? Couldn't find any info on that on the site.

Re: Team Driven 1730 Reveal
 

Yes, they are all going to be on the floor of Barnhill Arena with the game court at one end. We are finalizing pit map and layout now. It is a smallish venue, but we only have 36 teams. If we keep the current layout, your pit looks to be about 60 feet from the playing field.

Re: Team Driven 1730 Reveal
 

That's awesome. I sort of like the smaller venues. You get to know teams on a lot more personal level.

Re: Team Driven 1730 Reveal
 

Since we are 1/3 rookies, you will be getting to know a lot of teams on a personal level!

Re: Team Driven 1730 Reveal
 

We are bringing a bunch of tools, and spare parts. We love helping teams and we come prepared. 1730 will have our pit open for anyone.

Re: Team Driven 1730 Reveal
 

I would expect no less. You guys are the best!

Re: Team Driven 1730 Reveal
 

I love this quote and mentality! If our district didn't restrict out of state trips we would've come to Arkansas. We loved it during the off season.

Great Robot 1730! The sideways thing through me off at first. Will make defensive planning a little harder. That climbing apparatus is also pretty interesting, I assume the second pair of hooks holds you stationary after you reach that rung and you can continue to 30? Your video didn't show :(

Re: Team Driven 1730 Reveal
 

Yes. The first set of hooks are also spring loaded so the top ones "hand off" the bar to the shorter ones to allow the robot to continue up the pole.

Re: Team Driven 1730 Reveal
 

Great Looking Robot. I look forward to seeing it in action.

Re: Team Driven 1730 Reveal
 

A few tech specs in case you were wondering:

• custom designed, dual output AM SuperShifters with gearing for 4.5 and 18 FPS
• custom designedn 24:1 dual miniCIM gearbox mated to a worm gear with a final reduction of 300:1 for our Pizza Box
• dual miniCIM shooter using BaneBots orange wheels
• weighs 119.3 pounds including not yet mounted camera
• low gear mode has the ability to push me sitting on the carpet (about 140 pounds)

Feel free to ask questions

Re: Team Driven 1730 Reveal
 

Thanks, your guys' looks pretty awesome as well. Hopefully we both can get some practice time with each other. That would be nice so we both get some time with other robots on the field

Re: Team Driven 1730 Reveal
 

How about some time tonight?

Re: Team Driven 1730 Reveal
 

Sounds good to me.

Re: Team Driven 1730 Reveal
 

What made you decide to orient the shooter sideways relative to the drivetrain?

Re: Team Driven 1730 Reveal
 

The sideways oriented shooter was inherent in this design. This design came as it's own concept as a whole robot instead of the typical sub-systems due to the nature of this concept.

Re: Team Driven 1730 Reveal
 

Also we were thinking of going straight on, but if you think of basketball, the defender moves side to side and the shooter moves side to side to avoid defense. We believed this potential could be a heavy defensive game, we decided to go side to side. Instead of having to back up, and realign, we would just get square with the goal, and if defense does show up we can move side to side to avoid the defense without having to realign with goal. Shooting whenever we have the chance.

Re: Team Driven 1730 Reveal
 

This is spec for 6 inch wheels. We changed mid way through to 4 inch so our FPS drops to 2 1/3 in low gear and 12 in high gear

Re: Team Driven 1730 Reveal
 

That's one heck of a low gear...any particular reasoning behind this change?

Re: Team Driven 1730 Reveal
 

Wanted a higher torque, more "pushy" mode for fighting off defense and low speed z turning for aligning shots. Not to forget that 6 inch wheels were a bit too heavy as we are at 119.3 with 4 inch wheels

Re: Team Driven 1730 Reveal
 

Great looking robot! Can't wait to see you guys up at Fayetville should be a lot of fun!

Re: Team Driven 1730 Reveal
 

I understand going to smaller wheels for weight, and lower speed for alignment, but lower gearing =/= more pushing power/torque in general. The amount of pushing power you have is directly related the the traction of your wheels. Once your wheels break free and start spinning on the carpet, it doesn't matter how low your gearing is, you can't increase your pushing power. For most FRC robots running 4 CIM drive at 150lbs (with battery and bumpers) and high grip wheels like the Andymark tread or blue nitrile roughtop from McMaster, this gearing limit is around 11-12 ft/s. At that speed, you will still spin your wheels on the carpet when you run up against a wall/another robot/etc., so gearing lower does not help your ability to push. Gearing faster than that, in general, will cause you to stall your motors before your wheels break loose. This is bad, and will blow breakers and overheat motors.

The exact gearing that this occurs at is dependent on the actual coefficient of friction of your wheels, the motors you're using in the gearboxes, and the total weight of your robot. This is why most teams that do 2 speed gearboxes run around 5-7 ft/s in low gear and 15-19 ft/s in high gear, giving them one traction-limited gear that will accelerate well and won't stall the motors in a pushing match, and one high-speed gear for getting around the field quickly.

The good news is that at 2.3 and 12 ft/s, both of your gears will probably be traction limited, so you're probably not at risk for stalling motors. They're fine speeds for driving around the field and for precise alignment. Just don't be fooled into thinking you get more pushing power out of the low gear. Unless your high gear stalls the motors before the wheels spin, they will both have the same amount of pushing power.

Re: Team Driven 1730 Reveal
 

I think what shocks me the most about your machine this year is the lack of 8020! What caused you guys to move away from that material this year?

Re: Team Driven 1730 Reveal
 

Team Driven robots haven't had a lot of 8020 for the last few years (2010 was the last robot with a lot) It's heavy and unnecessary most of the time.

Re: Team Driven 1730 Reveal
 

We haven't used 80/20 for the chassis since 2010. 2010 (rev 2) through 2013 have all been welded tube

Clint beat me to it.

Re: Team Driven 1730 Reveal
 

Our coefficient of friction on the VEXpro wheels is 1.2 which is higher than most others and our weight full loaded will be around 175 meant around 150. I can't think right yet. I haven't recovered from build season. (putting weight in bumpers to use as a counterweight)

Re: Team Driven 1730 Reveal
 

You should look at the Q&A, specifically Q480:
Can weight be added to the bumpers as long as you stay under the 20 lbs limit?

No, BUMPERS must be constructed as outlined in [R24].

Re: Team Driven 1730 Reveal
 

I haven't seen the actual bumper construction but using Figure 4-4 (Bumper Cross Section) and the "1 in. limit for hard parts", you can add right at 14.5LBS to a otherwise "normal" set of bumpers simply be using 1"x1"x.125" steel angle iron (.8lbs per linear ft) on both the top and bottom of a full-perimeter set of bumpers.

While this might be considered playing in the grey area of the Question 480 response, it wouldn't seem to be in violation of R24 in any way I can see.

Further, by using .1875" or .25" angle iron you could increase your bumper weight even more!

Re: Team Driven 1730 Reveal
 

120 lbs robot + 13 lbs battery + 20 lbs bumper = 153 lbs.

Mike is right about the metal trim. There doesn't seem to be be any specs on what that trim must be, so using it to add or manage your weight should be perfectly legal, as long as your bumper assembly remains under 20 lbs. We considered doing it ourselves, but found a place to put the weight within the robot. I think the Q&A response refers to adding "weight" in the form of some ballast piece that is not part of the legal bumper construction.

Re: Team Driven 1730 Reveal
 

The "pegs" that attach the bumper to the frame are solid blocks of steel with absurdly large hardware to hold it all together. Nothing illegal that we know of. Like jspatz1 said we aren't putting a ballast in the bumpers, just over constructing them within bounds

Re: Team Driven 1730 Reveal
 

So I understand why you guys did it. But how are you liking having your shooter facing perpendicular to your robot's driving direction? Are your drivers handling it okay? 1405's 2012 robot had the same set-up, and I was not a fan. I felt it made driving a little counter-intuitive.

Re: Team Driven 1730 Reveal
 

I personally like a lot. It seems easier to realigned to a target if the first shot is off. It does get a little tougher lining up with the feeder station but after a batteries worth of driving and trying different possible ways to pull up to the feeder station I finally got it figured out. I haven't found any big issue besides the feeder station one yet. So no big complaints.

Re: Team Driven 1730 Reveal
 

Like Luke said, it's a lot of personal preference, but I tend to find it easier to evade being defended since you can strafe instead of having to realign a shot every time