Re: Team Update #1
 

Wait ... those duck races are THAT exciting?? :eek:

Re: Team Update #1
 

I don't see an issue here. I see that the hostbot cannot contribute to the vertical motion of the minibot. Fine, no problem. I'm seeing that you can't have stored energy in a spring, everything must use the motors. Again, no problem.

I'm not going to reveal why I don't see the problem yet. I want all of you to try and see what I am saying here. Try and calm down, step back from your infinite rage and look at this like an engineer would. You found a loophole that said you could launch the minibot from the hostbot, I see another loophole yet to be closed, if it ever will be.

::rtm::

Re: Team Update #1
 

Engineering still can't beat Physics! There's only some much weight to remove from the minibot, so it may eventually come down to, as someone pointed out, to whoever has the fullest battery or, completely ridiculous, who got lucky and received the slightly better spec'ed motor from the assembly line...

As for the fun of watching one robot beat the other by milliseconds, maybe I'm just weird, but the kick I get from 100m dashes is watching Usain Bolt crush records, not the other seven "regular" guys who all arrive at the same time - by the way, there's no photofinish at a (incredibly long and slow) marathon...

Re: Team Update #1
 

[quote]As for the fun of watching one robot beat the other by milliseconds, maybe I'm just weird, but the kick I get from 100m dashes is watching Usain Bolt crush records, not the other seven "regular" guys who all arrive at the same time - by the way, there's no photofinish at a (incredibly long and slow) marathon...[/quote/
As a track and cross-country coach, I have seen some long races change in the last second. I see the difference between launching and climbing with motors more like the difference between the 100 meter dash and the 4x400 meter relay, or the 1500 meter run.

More seriously, why is it more exciting to see which hostbot is a tiny fraction of a second faster at deploying the minibot and triggering a launcher?

Re: Team Update #1
 

This is the first design that our team thought of.

Based on the initial rules, we sort of inferred that the intent was that the MINIBOT was self-propelled, but not necessarily battery powered!

Re: Team Update #1
 

Joe I think you are correct...and I edited my post after checking with some folks ... I either originally saw it wrong or things went that fast....

Re: Team Update #1
 

I for one am thrilled at the lastest team update. During a match, while I am announcing I stand right next to the field...I didn't really like the idea of taking a 15 pound piece of metal to the squash because someones latch failed to activate and the spring misfired. Phew!

To anyone who thinks this will not be exciting, you are out of your mind! It is NOT like hanging first off. You did not get more points for hanging first as you do for finishing first with the minibot. That 10 point difference between 1st and second could be a huge make a break moment in an elimination match. To me, it doesn't get any better than that!

As for the design challenge...if you don't think there is a challenge in trying to get your minibot to go faster than everyone else, you are not thinking outside of the box enough in my opinion. Once again, instead of complaining, suck it up, think a little harder, and make the most of what you do have.

From what I can tell, there are ways around, or ways to alleviate all the complaints which people have posted here...all it takes is for a little hard work. Get on it!

My only actual question is this...who can register a minibot? An FRC team? An FTC team? A team of random mentors and students with no affiliation? A team of mentors with no affiliation? A volunteer? I don't see this clarified anywhere...it might be slightly important to know.

Good luck everyone!

Re: Team Update #1
 

The difference is that with hanging, there are a multitude of different designs and options. Between looking cool, going up fast, elevating past the buzzer, and otherwise, there is a lot of variety that is exciting to watch.

This game, the laws of physics pretty much dictate a maximum speed and there's maybe one or two ways to reach that speed - so it becomes a "race" in who deployed right at the 10.0 mark, or who got a lucky battery charge, rather than an actual demonstration of which team had a better engineered mini bot.

Re: Team Update #1
 

There is quite a bit of engineering and design work involved in objectively reaching that 10.0 mark that should not be tossed aside.

Re: Team Update #1
 

Don't forget: the difference between "wow, what a great deploy, first place" and "the refs have disabled your tower" is so infinitesimally small and so much more important than previous end games that I can see nothing good coming of it.

Either teams will release early and get away with it or teams will jump the gun and get their tower disabled based on a number the field cannot precisely display and that no one can see while simultaneously staring at the base of the tower.

Re: Team Update #1
 

I can't believe veterans here on CD are turning the Update into a VRC/FTC gripefest. This was a minibot challenge, not a PVC tube launching challenge. It's sickening that people are crying foul just because now they're forced to use a 'competing' or 'inferior' product. If you don't like the product because of principles, then don't do a minibot on principle. The rest of us who aren't strong-armed into one program or another will enjoy seeing the minibots make it to the top.

Karthik, Cory, if I didn't respect you two so much for your technical prowess and general logical GP practices I would be hard pressed to hold back the tirade I could type right now.

Re: Team Update #1
 

Jesse, even those of us who do neither FTC nor VEX and who are sitting out the FRC competition are complaining. It's turning a mousetrap car (with the option for FTC) into an FTC robot. That could be good, or it could be bad, but either way it's changing the rules in a major way.

There were a number of ways to eliminate unsafe launching and declare a minimum weight equivalent to the FTC battery. Minibots must contact the tower during the entire deployment, minibots must have a minimum weight of X, the list goes on. Instead of one that allows for stored-energy designs, they went with the most restrictive rule they could. After teams had already started their FIRST Choice ordering.

Re: Team Update #1
 

Eric,

You aren't really taking mechanism failure into account. Just saying that a robot has to be constantly touching the bar during ascent, doesn't mean that it will happen in actuality. When you consider vibration, massive collisions, robot failures, having a 15 pound spring loaded vehicle on your robot is incredibly hard to make safe, let lone the damage it could pose to your own robot's internal systems.

Re: Team Update #1
 

I agree this is an important question. TU1 includes one pertinent reference:
So we know that either FRC or FTC teams can present MINIBOTs for inspection.

Eligibility of walk-on MINIBOTs does not appear to be defined by the Manual.

Re: Team Update #1
 

The physics here are pretty straightforward. There's absolutely no stored energy allowed, besides the battery. You can only start using the energy in the battery after DEPLOYMENT. The only way of converting this to mechanical energy is through the provided motors, which have a peak power output of 8.4W. So it works out pretty simply:

Work = Force x Distance = (Mass x g) x Distance
Power = Work / Time
Time = (Mass x g x Distance) / Power

So, you want to minimize Time by fiddling with things on the right hand side:
g - acceleration due to gravity. Let's all please assume this is constant.
Distance - nearly constant. Serious teams will deploy as high as possible.
Power - Max available is ~16.8W. Make your minibot as efficient as possible, with little friction and appropriate gearing.

Mass is the only variable teams have any significant control over. There's two approaches here:
1. Build a stripped down "dragster" with 2 motors, 1 battery, (maybe) 1 controller, and the minimum frame, gearing, and wheels to make it all work. There's an obvious minimum here of 1 battery, 2 motors, and some wiring.
2. Leave the motor, batteries, and controller on the ground and send up something lighter to hit the trigger for you. This has the potential to be rather faster than option 1, what with the huge weight reduction. But this is only possible if minibots are allowed to expand outside the starting 12"x12"x12" box. Given the massive restrictions just implemented on minibots, do you really think the GDC is going to leave that avenue open?

As people have been saying, it's just about down to a pure physics problem at this point. He who builds lightest and best wins. Successful minibots will have optimal gearing, 2 wheels, and as little framing as possible.