Is 12 hours enough?

OK… after countless constructive criticisms from close friends and other engineers a few members on our team are looking to completely re-do our robot on Thursday at nationals in 12 hours… most is already implemented but still mechanical changes need to be made…

picture - http://www.chiefdelphi.com/media/photos/23202
- http://www.chiefdelphi.com/media/photos/23201

1 - make our bot faster… we are already going to change the sprockets on our wheels from 44 to 30… we were a 1:2 from the KOP trans and are looking to get to 1:1 or 1:1.25 ish… that is an easy change to make considering we have to take some weight off of our robot anyways where we are taking off the side plates to get to the drive train…

2 - we have a turret… but it was scraped before ship because of functionality… here was the problem… with our design for our magazine ball storage in the back there was no way to get the ball constantly to our shooter from the magazine while the gun was rotated more than 5% in each way off center… but the turret did work and the camera did track!!!

in reality all that needs to be done in our eyes is dropping our shooter a few bolts and finding a way to consistently feed our gun from the magazine…

but with the lack of want from most of the team members and lack of man power and dis-agreement from one of our mechanical guys its hard, especially after being to 4 events myself and knowing that turret will make our team a 2nd round pick to a first round… so i have a question for you all…

do you think its possible? why/why not… and would it be feasible for us do to this and live with the robot we have until off season???

If a team that’s robot wasn’t even shipped to nationals can get help from another team and build a robot that makes it to the finals then why can;t you guys tweak yours out in the same ammount of time?? just a little encourgement cause it has been done but from scratch.

Good luck :slight_smile:

I dont know if I would call this ‘completely redo’ing’ the robot.

The sprocket change sounds reasonable, but keep in mind by making it faster you will lose torque and ramp climbing / pushing power. You might get it all changed over and discover your robot has trouble moving from a dead stop, can no longer turn without playing morse code on the breakers… You will have very little test and debug time, and you may end up putting it back the way it was to begin with.

As for the shooter, you have a rules issue. If you did not ship the shooter with the robot, and it has not stayed with the robot from regional to regional then I dont think you can show up at the championship with the whole subassembly. The rules clearly state that you must ship the entire robot by the ship date. Any thing you add after that must be fabricated during the fix-it windows, and assembled at the event itself.

So even if you did build the shooter before ship date, and removed it before it was shipped, I dont think you can now legally bring it to any event.

you could bring the raw materials and fabricate another one just like it at the championship. That will be legal, and much more difficult to accomplish.

well the shooter is on the robot we can shoot as is… the turret is on the robot as is just the motor is not connected to it so it stays stationary…

i do realize we will lose some pushing power by changing the sprokets but we all noticed that we were incredibly slow compared to most teams at UTC and we feel that a small speed increase will help us more so than that small lose in torque… but its not really torque we are giving up are we? because the motor is still pushing out the same but just raw pushing power will be affected im not an engineer by anymeans and not that good in physics =P

and yes Tim… i remeber that team back in 04… they were in our division… crazy story that still gets brought up even today… so yes it is doable just hopefully our team gets motivated…

ok, when you said the turrent was scrapped out, I thought you meant literallly

if the parts are all there then I would give it your best shot. Have a time schedule for the tasks that need to be performed and accept that if you fall behind schedule at some point, or hit a show-stopper, you might need to revert back to the way it was.

This is one of those engineering trade-off situations. By changing your robot you are taking a risk that something might go wrong, you might not be done in time (miss your practice matches or not able to play in some of the seeding rounds), or there might be some un-expected adverse side effect created (that makes the bot worse in the end).

and at the same time if you are successful then you will have a better robot on the field. The deciding factor is whether the gain (reward) is worth the risk.

Well, let me tell you about a time back in '02 I think it was. Picture the Midwest Regional with a lot of great teams. Pits open and Beatty opens their crate and proceed to tear down their robot. They had decided that their original design wasn’t going to work and a major rebuild began. As I remember it was about four o’clock before it was finished but they did get it done.
Yes there is a tradeoff between speed and torque. Increase the speed and reduce the torque. I agree with Ken but on a slightly different view. If this is your first (or worse if your second) regional then your drivers have practiced with a robot that drives differently than what you plan. That could be devastating until your drivers become accustomed to the new response. If you are going to be at a regional where there a lot of teams, you may only get 6 matches. Losing 1 or 2 will drop you in the standings. This is a big gamble if you choose to remanufacture your robot. We have a turret and have done very well and were not second round picks.
Choose Wisely!

We had a turret so good it helped us win the innovation in control award. But it didn’t get us picked for finals. I don’t think having a turret is as valuable as you may thing. Being able to drive your robot into a good shooting position is better.

A good turret that can auto aim with the camera is invaluable during the autonomous mode though. You can take a hit from a defending robot, get knocked out of whack, and still manage to get a few of the balls into the center goal. A stationary shooter that gets hit during autonomous just wastes its balls and ends up firing them into the crowd.

If you can get it to work without spending too much time, then go for it. Goodluck!

I’m going to say that trying to get a turret to work in the time you have is just not a feasible idea. Not because the mehcanical side of it won’t work. You already have most of the hardware present and 12 hours is enough. My team went through 4-6 major drivetrain overhauls this year depending on how you count them. We did it and never missed a qualification match and only a couple practice rounds. However in constantly changing our drivetrain we screwed up one very important part of this game, programming. Nothing was ever settled and the programmers had to constantly tweak gains and alter programs to make sure their old code still worked. In the end even though we had at various points a working camera we ended up just going for 10 balls in the corner because the code broke and we didn’t have the time to fix it.

So what i’m trying to say is, i’m all for physical modification but be careful. If you have 12 hours plan to do at most 3-4 hours of modification so that the rest of the pieces can fall into place. Drivers need practice and the programmers need to code. The faster drivetrain will be useless if the drivers can’t control it and that turret won’t be useful unless its pointing at the green light.

Thats all from me. :slight_smile:

thanks for the input ian =D

as for programming we had the camera following the light… so in that point during user driver mode… we could havce a working turret… as for auto… it was never put in play… i would have to write something and just try it, or i can get a friend or 3 =D to help me with thier code… so i dunno like you all said there are payoffs and additions… =/… guess the team is going to have an interesting next meeting… =D

Changing the sprockets is easy enough, but I’d leave it at that. You guys put up a pretty good showing at UTC, and you still have room for improvement without mechanical changes. (I believe you went from no autonomous to shooting about 4 in by the end of the regional… eh? :slight_smile: )

Remember, its not what round you are picked in, its what alliance you are in. I would rather be the last pick with 2 decent shooters than the first pick with 1 good shooter and a box on wheels.

yes i gotta thank you tom for mostly writting our auto at UTC so thank you sir =D…

sprockets i think we will definatley do looking at it… but as you said in your 2nd statement… look who won Boston… a defensive box bot + 2 AMAZING shooters… this was the same case at very few regional where it was 3 good shooters you are right… but we only made shots in 3/4 of our matches and only 3 matches outta 10 we had more than 2 shots in… thats horrible… if we can even DOUBLE that amount by making the turret work i think it will be worth it because right now i dont see this robot with the way the game was played at UTC very defensive i dont see us as a pick for elims… =/… but only time will tell eh?

In UTC we had our turret tracking in the pit, never worked on the field, we had it working in pits at SBPLI, wasn’t useful til finals.

Trust me when I say, without a true field test, you can’t say it works, and no offense to your team because I’ve seen your robot and I was very impressed, there’s a good chance it’s going to take more than a bit of tweaking to make it track, however if you would like some help, feel free to contact me in Atlanta, I’ve managed to make our robot score consistently in autonomous, even while being rammed, so I hope that means I know what I’m doing :wink:

thanks matt ill definatley take that offer up in atlanta =D

i remeber from seeing you guys in UTC but never saw the bot close up… you were using the camera to track on right? even w/o your turret?

we were also playing around with this idea with just adding the camera to track via drive train as apposed to the turret… it would take all the mechanical questioning and re-working out of it… so im not sure how much would go into making the camera track from the turret to the drive train *we took off the bottom servo to take out 1 part of the tracking, the turret moved side to side until it saw the target so im assuming i can do the same with the drive motors… point the bot at the light and have it fine tune w/ the drive like 358 and 40 do…

I hope this is inspiring to you:

At not one, but a few competitions so far this season, some teams have either not recieved their robot from the shipping companies at the regionals or had to completely re-do components or entire robots. Other teams are always willing to lend a helping hand, and a team at the Boston regional, 1962, had their robot worked on by people from at least 5 or 6 other teams. Everyone is there to help and you have a lot of brain power in those pits that are capable of getting you guys assistance, should you require it. While it may be challenging, you can definitely do it!

I think it may be possible. If you would like the help of 1002 in helping build your robot, please pm me. Thanks.