View Full Version : Our teams worries
Brandon_L
19-02-2008, 19:20
No pics, just sharing some facts like how many times we predicted we'll get disabled during a match.
We have a SINGLE scissor lift going up to knock the ball off and its flimsy. (Wasn't my idea...) If we hit the ball on the wrong spot, then the ball comes back down and pins our scissor lift. And if we do get it down and our arms are deployed, then were screwed becuase it will land on our arms (2 pieces of 1 inch wide steel tubing on each arm) and incompletely destroy them.
My prediction is that we get disabled about 4 or 5 times. Whats yours?
EDIT: I'll post some pics later.
EDIT AGAIN:
Some pics:
The robot without the side paneling with the arms deployed.
http://i187.photobucket.com/albums/x197/DIShoasting/P3190667.jpg
The scissor lift
http://i187.photobucket.com/albums/x197/DIShoasting/P3120626.jpg
Deployed lift
http://i187.photobucket.com/albums/x197/DIShoasting/P3120623.jpg
Prototyping of the arms. This is a working model and our final design.
http://i187.photobucket.com/albums/x197/DIShoasting/P3120597.jpg
http://i187.photobucket.com/albums/x197/DIShoasting/P3120596.jpg
BK Lounge
19-02-2008, 19:54
way to be a negative nancy. i dont think ur robot will break 4-5 times. just try abd avoid getting ur wooden arms rammed.
my team made huge metal claws. in a scrimmage they took one hell of a beating. hope u get nice opponents
DarkFlame145
19-02-2008, 19:56
ouch, a rookie team i take it? You may never know it might work better then you think.
zacattack
19-02-2008, 21:04
Your totally S.O.L.!!!!, if it fails at the comp rip everything off the and make a racing bot and nothing else.
Don't panic. If things go horribly wrong at the competition, ask your pit neighbors for advice or help. They will do their best to help you succeed.
It may go better than you think. Even if it doesn't, no matter how the robot does, you're still going to learn a lot, and that's the point of this exercise. Don't give up.
Our rookie season, we had more robot problems than you can imagine -- six major drivetrain failures during matches, scoring mechanism design problems, and general steering problems (casters can result in a robot that drives like a broken shopping cart). We kept plugging at it and troubleshooting between matches. We didn't ask for help, but in retrospect we should have. By the end of the regional, there probably wasn't another team there that could change a broken axle as fast as us. The next year, our robot was a lot more mechanically and structurally sound. This year, it's pretty nice, and we weren't bolting on major assemblies for the first time on ship day.
Based on your analysis of your robot, I'd suggest keeping the claws in to protect them while the lift is up. If you're a punch and herd robot, you're not likely to need to use both at once. I'd also suggest adding chain tensioners to your drivetrain at the regional if you haven't since those pictures were taken, since your chains are long and look a bit loose. (That's part of what did us in as rookies.)
Akash Rastogi
19-02-2008, 22:49
Don't panic. If things go horribly wrong at the competition, ask your pit neighbors for advice or help. They will do their best to help you succeed.
Based on your analysis of your robot, I'd suggest keeping the claws in to protect them while the lift is up. If you're a punch and herd robot, you're not likely to need to use both at once. I'd also suggest adding chain tensioners to your drivetrain at the regional if you haven't since those pictures were taken, since your chains are long and look a bit loose. (That's part of what did us in as rookies.)
Yeah, I totally agree on these points. Which regional(s) are you attending btw?
All in all, the robot really isn't what matters, as cliche as that sounds, you do end up learning an amazing amount of stuff on the field and in the pits. All I can say is good luck and I hope you do great :]
btw, how high up does the scissor lift extend? It looks to me that you could have shortened it and used that loss of weight to add something that would create more stability for it.
DarkFlame145
20-02-2008, 12:27
I know it looks bad, but our team (145) has been around for 11 years now and last year was one of our worst. We started our with an awesome design, but as the build season went one we fount out that things weren't going to work. So almost everything BUT the drive train was redesigned. Well in the long run we where up at 3Am trying to finish our robot the day before ship. The bot went into the crate in pieces. We spend almost all of our first day at competition trying to get our arm and ramps to work. So we got in like 2 practice matches. Still at the first day of qualification matches all we could do is drive around and play defense. We didn't get our Ramps working until the LAST qualification match and we didnt get picked for alliance partners. The only good thing that happened is that we where the best defensive robot there. Dont let things get ya down and out cause you may never know things might bet better then you think. But if they arn't look twords next year.
dtengineering
20-02-2008, 12:51
I notice this is your rookie year. Just having a robot that passes tech and moves around the field is no small acheivement. It sounds like you would like to have your robot at a more advanced stage of development, but I can assure you that you are far ahead of where we were in our rookie year.
You will find that as you learn and as your team develops that the robots will become more advanced and meeting ship deadlines will become easier. Most importantly, however, when you get to the competition you will find that there are lots of people there to help you out and lots of opportunities to improve your machine.
In our first year we got to the tournament only to discover that we couldn't turn! We had done all our testing on cement, and the carpet had wayyy to much traction. We spent our practice day modifying the robot to turn (thanks to some help from team 1241... Rick Hansen Secondary for helpful advice and a lift to Home Depot among other things) then lost every match on Friday. All day Friday the students kept working on the robot, and completely changed how the robot worked.... we won every match on Saturday... although luck played a role (bad on Friday, good on Saturday) seeing our hard work pay off made it feel like we had won the whole tournament.
Don't stress that the robot you put in the crate is not exactly the robot you WANTED to put in the crate, or the robot that you expect to finish the competition with... there are about 1,400 teams around the world thinking the exact same thing... the other 100 or so probably don't have a clue what they are getting in to!
Jason
Daniel_LaFleur
20-02-2008, 13:03
Well, I don't think you are screwed as you state you are, but you do have some valid concerns.
First off, I'd get the programmers to pull the sissor lift down as soon as it hits it's max height, thus avoiding the ball coming down on the sissor.
I would also put some sort of protection on the end of that sissor as those corners look sharp and I do not believe you will pass inspection with those sharp corners.
Wood is not a bad choice for your gripper as long as you work with the grain. Wood has plenty of give before it breaks so the ball should not bother your gripper too much. I would be very cautious about interaction with the playing field or other robots though as they can generate far higher forces. You may want to consider creating a replacement set, or possibly redesigning them to be made out of Aluminum surrounded by PVC.
Your drivetrain looks decent enough so you should be able to score points running laps.
One more thing ... the robot looks like it has very little guarding. I'd suggest some Lexan sheeting around the robot to protect it's innerds from wandering robot arms.
This is all a learning experience, especially for rookie teams. good luck and remember to have fun.
Brandon_L
21-02-2008, 19:03
Well, I don't think you are screwed as you state you are, but you do have some valid concerns.
First off, I'd get the programmers to pull the sissor lift down as soon as it hits it's max height, thus avoiding the ball coming down on the sissor.
I would also put some sort of protection on the end of that sissor as those corners look sharp and I do not believe you will pass inspection with those sharp corners.
Wood is not a bad choice for your gripper as long as you work with the grain. Wood has plenty of give before it breaks so the ball should not bother your gripper too much. I would be very cautious about interaction with the playing field or other robots though as they can generate far higher forces. You may want to consider creating a replacement set, or possibly redesigning them tobe made out of Aluminum surrounded by PVC.
Your drivetrain looks decent enough so you should be able to score points running laps.
One more thing ... the robot looks like it has very little guarding. I'd suggest some Lexan sheeting around the robot to protect it's innerds from wandering robot arms.
This is all a learning experience, especially for rookie teams. good luck and remember to have fun.
THe sharp points have been taken care of.
"First off, I'd get the programmers to pull the sissor lift down as soon as it hits it's max height, thus avoiding the ball coming down on the sissor."
Dude I LOVE you!
One question on that. Would that require a sensor or something?
For those wood things, we have a few backup sets.
And those are shots form before we put lexan on. We did :)
Cooley744
21-02-2008, 19:15
Last year we used PVC arms and they broke almost every match! lol it was fun making tons and tons of spare arms for off season competitions!
Dr Theta
21-02-2008, 20:42
All of the posts above are valid. In situations like this I like to whip out my copy of the hitchhikers guide to the galaxy and take a glance at the cover. I don't know why the word's DON'T PANIC are so soothing. From the looks of things you are actually in pretty good shape. If worst comes to worst you can transform it into a box on wheels, which in this particular game can still be quite effective. But let's not start chopping limbs off immediately. As the previous posts have already said, there is plenty of help to be found once you are at the regionals. None of the teams wants to see another team fail and you will find that most if not all of them are willing to help, and those that aren't probably have problems of their own. I also find that the inspectors themselves to also be very helpful. So, in conclusion, take a deep breath, relax. Things aren't as bad as they seem, put a smile on and get ready for the plunge. For young teams in particular I recommend making connections and soaking in the atmosphere. Have fun!!;)
Daniel Bathgate
21-02-2008, 22:30
Hey, we had one of the exact same problems with our ball poker (a PVC pole that is winched up inside of a slightly larger piece of square aluminum). We found while testing at the Cheezy Poof's field (thanks again, guys!) that if we hit the ball near the edge, the ball wouldn't fall down but would rather push our pole against the overpass rail while it was coming down. Doesn't sound so bad, except that it became impossible for our winch to retract the pole, causing the fuse in the spike to blow, and leaving us with a robot trapped in the tiny square of the overpass. Eek! We replaced the pole with something that won't bend (huzzah for spare axles that fit inside pipe!) and added a rangefinder pointed straight up so it will be easier for us to know when we're under the ball to hopefully mitigate the problem.
Depending on how fast the scissor lift is, retracting as soon as it is up may not be enough. Our poker did that (after a small delay to reduce wear on the winch transmission) and still got pinned, though it's certainly a good idea to come back down as fast as possible in any case. Hitting the ball closer to the center would probably be the most effective strategy, and the drivers can use the tape on the finish lines to help them line up, something we couldn't do on the practice field.
For being concerned about the ball landing on your arms, could you just turn the robot before you poke or if the ball starts to fall? It would take more time, but should help prevent that problem if the arms are safely under / on the other side of the overpass.
And high five for your fellow ball-poking and arms-for-herding robot! Hurdling is SO overrated! :D
Brandon_L
22-02-2008, 10:04
And high five for your fellow ball-poking and arms-for-herding robot! Hurdling is SO overrated! :D
:D
Where is the tape at compared to the ball? Is it right under the center of the ball?
Daniel Bathgate
22-02-2008, 14:01
:D
Where is the tape at compared to the ball? Is it right under the center of the ball?
It's under the far rail of the overpass, aka away from the center on your side of the field and towards you on the other side. So definitely don't center yourself on it, but it should still be a useful visual indicator.
Nathan_Fraser
22-02-2008, 14:10
First of all, congratulations for getting this far!
Part of FRC and design/engineering is perseverance. While I agree with the "Don't Panic" mantra, I would go a step further. Keep your chin up, your thoughts positive, and have respect for your work and the work of your teammates. It looks like you've done great work. Keep it up.
Daniel_LaFleur
22-02-2008, 14:34
"First off, I'd get the programmers to pull the sissor lift down as soon as it hits it's max height, thus avoiding the ball coming down on the sissor."
Dude I LOVE you!
One question on that. Would that require a sensor or something?
There are 2 ways of doing it.
One would be to put a sensor (and sensor flag) in. The easiest spot looks like at the extended point of the cylinder.
The other option (probably the better of the 2) would be to time the time it takes to fully extend the cylinder (sissor) and then use a timer in software to retract it. The reason I say this might be better is because if your sissor hits something on the way up (like the overpass) the sissor would stop and your RC would never see the sensor.
BTW: 1824's 1st robot was a kitbot drive and frame only ... you guys are miles ahead of where we were.
lproxster
23-02-2008, 19:17
Dude, don't worry about it.
Last year, almost everything that could possibly go wrong with our robot did.
We still had fun though and we learned lots! :)
Best of luck this year!
Devibeast
23-02-2008, 19:26
Parts will break and they will be fixed, don't worry teams will help you after all FIRST is built around G.P.
Blue_Mist
23-02-2008, 19:42
Ah yes, every year we have learned how to change a battery in 30 seconds or less just before a match because someone was programming, that a six-wheel tank drive can work fine even if one of its chains is lying on the field, where to put the laptop on the robot so the program downloads en route as we are rushing into the queue line, how to build a completely new gripper from spare parts, that diamond plate is incredibly resilient (crashed gripper into the wall, which bent like an accordion), how to straighten out said gripper (made it through the matches until we built a new one!), and of course, what to do if your robot catches fire.
Don't worry about winning. If you're a rookie team, then just having a functional, non-kitbot drive train is a grand achievement. Defense has always played a huge part in games, whether it was encouraged. And of course, ask for as much assistance as you need. Every team in the Pits either wants to help or needs the help. Sometimes both!
Just curious have you guys weighed your robot?
You mentioned that you have spare wooden arms, do you also have spare scissor lifts? This would be a good idea in case it breaks but also depending on your weight maybe you could tie the two lifts together to make it less flimsy.
Al Skierkiewicz
24-02-2008, 10:53
Brandon,
This competition is not about preventing you from competing, even inspectors will do everything they can to help you have a great weekend. I figure if you show up to play then it's my responsibility to make you play. You are out there with two other robots, you are not playing alone. If those robots need you to knock a ball off the overpass then you do it. If they need you to herd because all they can do is knock the ball off, then you do that. It is all about the alliance succeeding, not the individual. Also remember that you can change things at a regional event before you get inspected. The pits are open all day Thursday and each regional will have a practice field. Bring enough raw material for a design change (under 25 lbs. please) and ask other teams around you for help or ideas. Look at the other robots and ask them how the robot works. You might just find you have a unique design at your event. You can, as a team, decide the shortcomings and decide if you need to beef up the structure or replace it. It looks like you certainly have enough weight to make changes or add to your design.
Finally, you are a team, and the team makes the decisions. You rise together or you go down in flames together but you do it together. If you don't make it into the finals, then pick a team who has and cheer like crazy for them.
Good Luck.
Brandon_L
24-02-2008, 11:30
Just curious have you guys weighed your robot?
You mentioned that you have spare wooden arms, do you also have spare scissor lifts? This would be a good idea in case it breaks but also depending on your weight maybe you could tie the two lifts together to make it less flimsy.
No, the arms are 1 inch steal tubing. The wood you see in the pics are prototypes. We have spare grippers for the lift.
And yes, we did weigh it before we shipped it. SInce we had to put it on an electronic scale and we couldn't really see the scale becuase the robot was in the way, we got a rough estimate. We only saw the first two numbers but its still underweight. I looked under and saw 11X (X being the # I couldnt see)
Anyway guys, thanks alot, you've helped a ton!
One more question....
We blew our IR board. At the competition there is a bin or something where we can swap for a working one, no?
If so, We'll get on wiring that as soon as we get to the comp :D
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