Robotics Question of the Day!
 

Hi, All

We're looking for questions related to robotics that would start our meeting off. They can be related to pretty much anything as long as the average kid can answer with a bit of thought. We'd like a fun way to get the kids' minds going and would like to try it out. Also, if your team is doing this, how is it going? Feel free to use this idea if you'd like.

My example was, "How can decreasing a drivetrain's gear ratio increase its top speed?"

Post your questions below.

Thanks,
Ryan

Re: Robotics Question of the Day!
 

Here are a few.

1. If FIRST changed the rules and allowed you the option of a second battery, would it be an advantage to use it, a disadvantage, or does it depend on the game, your strategy, etc. and how?

2. Each year there are robots with different drive mechanisms, but only a few types seem to be represented as a significant percentage in the finals. What is it that makes some of the different drive trains more or less competitive?

3. When building a robot you can choose different materials for the frame and other key parts such as aluminum or steel tubing, strut, sheet metal, wood, plastic, etc. How do the properties of these materials affect the choice and how many properties are there that are important in a decision on what to use?

4. Many teams are building T-shirt launchers to help promote their teams. If you wanted to build one, what design factors would you need to consider if you wanted to shoot T-shirts into high bleachers.

Re: Robotics Question of the Day!
 

Here's one I used for discussion in an FLL team I mentor:

What would I have to do to a two wheeled vehicle to make it stable? (Make them think outside the box- I got some really interesting responses, some of which were practical and helpful)

Re: Robotics Question of the Day!
 

How can increasing a drivetrain's gear ratio increase its top speed?

Re: Robotics Question of the Day!
 

Confusing to talk about increasing a ratio (e.g. 10:1) because it's unclear which quantity (1 or 10) you're increasing. Better to ask "How can decreasing a drivetrain's gear reduction increase its top speed?"

Re: Robotics Question of the Day!
 

When the gear ratio is too big for the wheel and motor combination. We experienced it this year. We put on a sprocket that was to small by accident and it would barely move. We doubled the diameter of the sprocket on the wheel and we were golden.

Thanks for the replies, and keep them coming!

Re: Robotics Question of the Day!
 

How about:

What is the most important part of the robot?
A.The drivetrain

What is the second most important part of the robot?
A. Game piece pick-up

Have to keep these in mind come design time, its easy to only think about scoring..

Regards, Bryan

Re: Robotics Question of the Day!
 

If you are 100% sure you can score 2pts in the end game, but have the possibility (~50%-65% chance) of scoring 3pts if you skip the end game, which should you choose?

This was something that we had to ask ourselves back in 2010 nearing the end of season on debating whether to add the hanging mechanism.

Re: Robotics Question of the Day!
 

Depends on whether the extra point is needed to win.

Re: Robotics Question of the Day!
 

Also bear in mind, for discussion on cd, that 2010 was year of the horror ranking system. But for purposes of the op's post we can throw that out the window since rookies are highly unlikely to understand (I sure didn't) the system.

Re: Robotics Question of the Day!
 

I guess I think about it as increasing or decreasing the equivalent fraction (10/1 in the case of your example). Maybe I'm wrong...

Right, I was pointing out that both are valid questions.

According to the Wikipedia definition at least, gear ratio is the ratio of the input speed to the output speed, so putting a larger sprocket on the wheel (or conversely, a smaller sprocket on the driving axle) would increase the gear ratio, creating a greater speed reduction. This reduces the theoretical unloaded freespeed, but, as I believe you're saying, can increase the top speed in torque-starved conditions.


Some other questions:
- Why is it important to keep electrical wires as short as possible? (Signal wiring and power wiring can have different answers, though there is overlap)
- What would be some advantages/disadvantages of using a smaller amount of a stronger but heavier material vs a larger amount of a weaker but lighter material (e.g. steel vs aluminum)

Re: Robotics Question of the Day!
 

Incorrect. A much smarter man taught me that the second most important part of the robot is... the drivetrain.

Do you want to know the third?

Re: Robotics Question of the Day!
 

Drivetrain. Mr. Beast.

Re: Robotics Question of the Day!
 

For rookies our first question of the day is

What does FIRST stand for?
If you can't get that down no point in asking them mechanical questions because they aren't getting FIRST

Some team specific questions are also always good:
What year did we start?
What was our first game?
etc.

I always also enjoyed this question:
How do Mecanum wheels work?

Re: Robotics Question of the Day!
 

No, the second most important part of the robot is also the drivetrain.

So is the third.

Game piece manipulation is no higher than fourth on the list of robot priorities.

Re: Robotics Question of the Day!
 

So "low gear" in my car has a high gear ratio,

... and "high gear" has a low gear ratio.

That's probably where some of the confusion comes in.

Re: Robotics Question of the Day!
 

How did the 2010 ranking system work?

Re: Robotics Question of the Day!
 

The seeding system led to the infamous Curie Match 100 where Simbotics catapulted themselves, legally, into first seed.

Re: Robotics Question of the Day!
 

By losing the match, I might add. Props to them though, playing the metagame is just as important as playing the game.

Re: Robotics Question of the Day!
 

Does that mean that Bumpers on #1? Please tell me bumpers are not #1...

Discussing ranking systems is a really good idea. FIRST likes to switch them up and sometimes this will influence how you design your robot.

A fun hypothetical might be:
Originally matches were 1vs.1vs.1
Then FIRST improved to the 2vs.2 format.
Then FIRST improved (by most folks opinion) to the 3 vs. 3 format.
How would FIRST change if they went to 4vs.4?
What would be the benefits and what would be the disadvantages to 4 vs. 4?

Re: Robotics Question of the Day!
 

Here are a couple that go along with what Brian mentioned. Being a teacher, I like to create discussion based questions:

Q: How many speeds/gears are necessary for the XXXX game?

Q: How many different ways could you pick up an innertube/basketball/other game piece?

Q: Where is the most important part of the field for the robot?

Re: Robotics Question of the Day!
 

Bumpers are #4, I think. The most important parts of the robot, in order:

Drivetrain, Drivetrain, Drivetrain, anything that makes the drivetrain legal (bumpers included), game object manipulation #1, game object manipulation #2, game object manipulation #3.

The difference in the game object manipulators: #1 is acquisition, #2 is delivery, #3 is either anything internal to the robot or working with any stationary field element. The reason they're game object manipulators is that it's quite possible that they may be dealing with stuff other than game pieces, like mobile goals or bridges or hanging bars.

Re: Robotics Question of the Day!
 

Objection: this puts non-object endgame work no higher than 8, when in several (but certainly not all) years, endgame was arguably more valuable than object (acquisition/delivery) scoring.

Re: Robotics Question of the Day!
 

Does it? Game objects, as I noted, may include such items as towers and mobile goals. Towers--hmm, like maybe 2010 and 2011?

The reason I specified game object (NOT game piece) is that there are often multiple objects that it is helpful to interact with by using a specialized mechanism. Say, the bridge or the towers mentioned. All game pieces are game objects, but not all game objects are game pieces.

I should also have mentioned that the #1, #2, and #3 designators can be shifted in priority--say, #3 comes first. (Though I don't suggest swapping #1 and #2; it's kind of hard to score a game object if you don't have one.)

In actuality, endgame work could be as high as #1 (iff it's done only with a drivetrain, like the 2006 ramps) or #5 (if it needs a manipulator to do).

Re: Robotics Question of the Day!
 

Lets keep the OP in mind guys.. ;)

Re: Robotics Question of the Day!
 

Apparently I started something here..

Revised list of important robot related functions assuming legality:

1. Drivetrain
2. Drivetrain!
3. Drivetrain!!
4. Picking up the game piece.
5. Drivetrain!!!
6. Processing the game piece..
7. Drivetrain!!!!
8. Delivering the game piece...
9. Drivetrain!!!!!

*4-10 Endgame (depending on game)

Interestingly enough this follows gameplay rather closely.. Drive, pick up piece(s), drive while processing, score, repeat.


Another fun question:

-What are the three tightest constraints on the robot?
(IMHO)
1. Money
2. Time
3. Weight

However, this one is more up for argument. :]

Regards, Bryan

Re: Robotics Question of the Day!
 

Q: Who should you not instantly blame for errors when they happen?
A: Programmers. It's good to break this stereotype sooner than later.

Q: What must be worn at all times when working on the robot?
A: Safeties, closed toed shoes, etc.

Q: Where is the FIRST aid kit located?
A: "answers will vary"

Q: Where is the largest/smallest gauge wire used on the robot?
A: "answers will vary"

Q: When working with aluminum and nuts/bolts, how much should you tighten them?
A: not too tight

Q: Where is metric crescent wrench?:D
A: I have no clue what you are talking about...

Q: Should a chain be completely taut?
A: No.

Q: Should the robot frame have a charge?
A: No. This can be prevented by isolating motors, and checking wires.

Q: What is the best type of drivetrain/mechanism?
A: The best one we can build w. our resources.

Q: If the robot does not turn on, what is the first thing to do?
A: Check the battery.

Q: What is called when you lend a team some part at a competition?
A: Gracious Professionalism

Re: Robotics Question of the Day!
 

What is the large PDF that everyone is supposed to read called?
A: The Manual.

Who needs to read the Manual at least once?
A: Everybody. Twice or thrice is preferred, though.

Re: Robotics Question of the Day!
 

Ok, I get the object vs piece distinction, but how can you indicate that #n is acquisition and #m is delivery? Are you referring to chronological steps in general (how do you deliver a bridge)?

Remember that {endgame} ⊂ #1 IFF endgame is done only with drivetrain functionality ⊂ standard movement. (The endgame may involve only the drivetrain, but well above and beyond standard movement.)

From the perspective of the OP, these questions are important. One of the worst mistakes you can make early in the design strategy process is mis-prioritize or used overly-constrained verbiage (thereby constraining minds). Look at the teams that ignored the minibot or constrained themselves to hanging on the horizontal bar in Breakaway [not that that didn't work for some also]. Given that Ryan's looking for ways to get kids minds going and inspire them to want to try it, such an open-ended "what's a good structure for determining the top priorities of a FIRST robot" question is actually a pretty valuable discussion of the day.

Re: Robotics Question of the Day!
 

http://www.walmart.com/ip/Vise-Grip-...rench/15720337

Free clue for the still-confused: The "metric" refers to the scale on the jaws that lets you know what size nut or bolt head you're rounding off when you use it.

Re: Robotics Question of the Day!
 

It's chronological in general, or in order of priority. For example, many teams may have thought that the order this year would have been delivery of the basketballs, acquisition of said basketballs, and being able to tip the bridge (because they could go over the barrier, and chances are someone else can tip the bridge). Actually, acquisition and being able to level the bridge took precedence--witness the number of stingers that mysteriously appeared on many robots as the competition season progressed, and the wide variety of over-the-bumper collectors. (Delivery of the basketballs was a pretty close second to acquisition wherever that ended up.)

I would agree that a "what's a good structure for determining priorities of a FRC robot" is a pretty good discussion of the day. I would, in the days and weeks after using that one, go even farther: I would pick a random FRC game (ideally one well before the time of the students on the team), slim it down to be easily understood, and ask the question, "How do we win this game?" The open-ended discussion there will eventually lead to an answer, right or "wrong", but it can be compared to the actual winning robots that year.

Re: Robotics Question of the Day!
 

Come up with as many unique ideas as you can in five minutes to do X action (ie picking ball up from the floor and putting them in a hopper). Give them another 5 or so minutes to figure out which idea would be the "best" in competition.