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Team 4264 18-01-2012 23:15

Laying it all out there
 
Well, so far you guys have really busted our design bubble about the FP motors so I'm just going to lay it all out and see what you think. Let me remind you that we are the rookie rural school with absolutely no help. No mentors, no engineers, no clue, no time, and not enough students (4-6 regulars), but we are going to build a bot!
Picture a U shaped bot, open in front. 1 CIM motor (front wheel drive)on each side in front with front being straight upper arms of the U. Caster wheels from and old auto creeper in the rear corners so that it can spin freely and quickly. Our strategy is to use this U shaped spin action to control the balls around the floor better. Balls come in and are directed toward a bicycle wheel being slowly but constantly turning by use of one of the slow torquey motors. Not sure how yet... Balls are directed back, up, and over,the tire by use of carefully bent rows of conduit to bring it up to the top. From there, create some baseball pitching machine setup that many other teams are using with I guess, based on answers from my previous thread, FP motors to drive the pitching wheels, though they seem a bit wimpy.
Motor list
2 CIMs (drive)
1 long torque motor (bike wheel)
1 servo motor ( a gate before pitcher)
2 FP motors (pitching machine)

Probably no time to test. Maybe no time to wait on part orders. What is average ship time on our voucher vendors?
Thats it. NO Kinect, no air system, no defender bot, and mostly junk from the shop.

PS.
Legend tells of a bot from rookies of the past brought in with no programming to compete yet the kind competitors swooped in and saved the day by programming it before the event. So legally (bag /tag rules) how is this possible at a regional event with lots of new rookie TN teams trying figure out what is going on?

VKP 18-01-2012 23:23

Re: Laying it all out there
 
I think it would be beneficial for you to use four CIM motors, and instead of using casters, I would use omni-wheels, which can be driven, unlike casters.

If you had casters and only two CIMs, you would be pushed around the field very easily. Omniwheels and two more CIMs on your drivetrain would help a little, while maintaining the turning capabilities you want.

A question though: why do you want to power the wheels on the "arms" of the U and leave the back of the robot to drag around? I'm assuming that with a U-shaped chassis, much of your weight will be at the back, so you will want powered wheels closer to your center of gravity so you can turn faster.

EricH 18-01-2012 23:28

Re: Laying it all out there
 
Awright, let me make a suggestion or two.

Casters: If you MUST use casters, and that's a big IF, use ball casters. Most teams avoid casters like they're the plague; they tend to give you trouble when steering. Ball casters are a little bit better. Omni wheels, if you can get them/make them, are the best on that. (That "spin freely and quickly" should also read "unpredictably" for casters.)

For the drive, try to get another couple of CIMs; AndyMark.com sells them for $25 each, and ships fairly quickly. (Oh, and if you haven't used your FIRST Choice credits yet, use them--that can help with resources.)

Slow torquey motor: grab a window motor. Use programming to slow it further if you need to.

With your comment on the "no programming"... You don't know the half of it. Try "no robot"; I've seen a team show up with the KOP and have a running robot in 6 hours; I've heard of a pair of 1-day robots due to shipping mixups. You show up with only a box of parts or a robot in any shape, look at the pit right next to you and ask that team for help--they're probably veterans. Then hold on to your seats as half the other teams come in at the same time...

MrForbes 18-01-2012 23:31

Re: Laying it all out there
 
You should buy two more CIM motors and use them in the drivetrain, and also don't use casters, they make your robot pretty hard to control. If you want to collect balls in the U opening, it should be as wide as possible, to make it relatively easy to do, that means you want a "wide" robot. A 4 wheel skid steer "wide" robot drives pretty well, it can turn easily. But it is kind of "tippy" front to back, so you'd need to keep the weight centered down low, and it sounds like your ball lifting idea would end up being kind of heavy up high on the robot.

You might see if you could use a roller to help collect balls, and a single belt to lift them (see videos by falconmaster on youtube).

You can probably get by with a single motor/wheel shooter, have the ball go over the wheel, that will give it backspin and make it more likely to land in the basket. One FP motor is sufficient, and you probably want a single stage of gear reduction...see if you can modify the plastic FP gearbox to do this. We've done it by just using the first plastic gear stuck in a box we made ourselves, but without some machining help it would be pretty difficult. See if you can find any kind of machine shop that might help you

SteveGPage 18-01-2012 23:33

Re: Laying it all out there
 
One concern I would have, when I hear "U shaped" robot, is the requirement to have the chasis still able to meet the bumper requirements. Assuming you have an opening in front of your robot, the front of each of the "arms" still need to be at least 8 inches wide for the bumpers.

As for "no mentors" etc... I commend you for your efforts of doing what you can. Our team has helped several rural teams in the past via email and/or skype sessions. If you would like to have some mentors advise you long-distance in the following areas: electrical, command and control (programming), CADD, mechanical, arm and end, chasis, drive train, Chairman's, or PR - let me know and I'll gladly schedule time for you to talk to any and all of them. We are happy to help in any way we can!

Akash Rastogi 18-01-2012 23:38

Re: Laying it all out there
 
Just focus on scoring middle of the pack and do it consistently. Play a little defense, and you will have a good time.

Also, post up here for help whenever you need something or PM specific questions.

PayneTrain 18-01-2012 23:45

Re: Laying it all out there
 
I think a good low budget item for any team is 1-inch aluminum angle of a moderate thickness (like 1/8 ?). If you do all of your fab in-house like we do, you go through a lot of 1-inch angle. Find a welder or bolt it together, you can create a sturdy frame that will hold up to high impacts. this will also create a structure that will be low to the ground and house all of your electronics. With this, lexan, and a good roller/belt system ,you can create a decent conveyor as well.

Buy stock gearboxes for the lift and launcher where you can. Use kit wheels on the launcher. Do whatever you can. if you aren't experiencing success with the launcher, work towards building a robot capable of dropping the bridge and balancing on it. If you are building wide, you could be invaluable in small regionals.

It's not going to be easy, but if you're determined, you will go out there and build a robot, it will run, and you will never forget the process and the friends you have made for the rest of your life.

And you're a rookie with no experience going up against teams that have been around the block enough to notice the bricks on the front of every house. Don't just have fun, go up to the veterans and see what they do. Ask for help, even though it will find you if you need it.

Godspeed.

SenorZ 18-01-2012 23:51

Re: Laying it all out there
 
1 Attachment(s)
Ah, the rookie experience...

DO NOT put two powered wheels up front with casters in the back. We did that last year. It pivoted TOO easily. Attached is a pic.

We later moved the powered wheels to the center and put 4 casters on the corners. It would WAY better, but still squirrely.

PS: No mentors? Not even a teacher or parent? "/

RoboDawg 19-01-2012 00:25

Re: Laying it all out there
 
Hi,
First take a deep breath, and remember this is not just about building an robot. This about all your team, they are in this process to learn. I am a mentor of a team from a similar sized town in a rural part of Idaho. Our first year we were frantic and stressed and wondered if we were doing something out of our league. I know it's corny but---DON'T GIVE UP. Build what you can! Let your team know that it's okay to not build the the best robot. It's okay just to be a team trying to be it's best. :]

fox46 19-01-2012 08:13

Re: Laying it all out there
 
Oh the rookie year! I still remember mine :rolleyes:
My rookie year in the FIRST competition was 2002 where we had to build a similar robot to collect foam balls and place them in a goal. We had a similar idea of a U-shaped robot that would collect the balls in a conveyor belt at the front and load them into a hopper which it would raise on a scissor lift and dump into the goal.... Of best laid plans :P

We ended up with a similar design to yours with a two-wheel and two-caster drive. It was slow as heck and that was the only reason it was controllable. Unfortunately since half or more of your weight is over two non-powered wheels, they are terrible in a shoving match. As far as collecting balls, the feeder mechanism would continuously jam up and once we got a few balls in the hopper, it didnt have enough power to lift. - It was a rough year but by far the most memorable! I remember thinking how overwelming the whole experience was and how "outgunned" we were by other teams. The next year however (using the same drivetrain setup too - not sure how that happened) we won the "driving tomorrow's technology award" which allowed us to attend the championship in Houston.

Try to take this year as a learning experience - a practice for next year. Learn as much as you can throughout the whole process and apply it next year. Write things down as you go so you can look back on your notes later.

Now - your robot. I would stay away from the Caster-wheel idea. Since your resources are limited, try to concentrate on doing one (simple) thing really well and consistently. I think you are on track with the U-shaped chassis. Look at the kit robot chassis and try to mimic its driveline. You have all the parts to build it right now with no machining skills needed. If you are going for a transverse drivetrain (long side of the robot facing forward), look at the kit bot design and "squish" it end to end, then leave the front side open to collect balls being careful to observe the bumper rules. Rather than building a throwing robot, try to make one that can collect balls and then bring them to the other side of the field. You are allianced with two other machines in a match and chances are that one of them will be able to shoot. You guys could be a huge help by just bringing them balls while they fire them in. If you want to be more ambitious, try to make a conveyor mechanism (taking note of the height restrictions etc) that can suck in three balls and then just drive up next to the fender by the nets and just pop the balls into the 2 point nets. If you can do this repeatedly and consistently you will have an even stronger machine. The most important thing in these competitions is to be reliable. Even if you have a very basic and simple machine, if you can score a few points a match and get on a ramp, you will be a strong competitor. These competitions are designed so that no one robot can do everything so being able to do one or two things really well rather than everything with mediocraty will make for a much better performance. Remember that in the finals, if you have a tiny robot that can collect 3 balls at a time, bring them to another robot and then be small enough to fit 3 robots on the ramp you will be VERY valuable as an alliance partner. Just by having a small robot that can drive around in the elimination rounds will score an alliance 20 points by getting all the machines on a ramp.

Just remember to have fun and learn as much as you can for next year!

FIRST competitions are like pancakes - the first one is always a disaster but at the end of the day it's still a tasty pancake and you've gotta eat it! mmmmmm.... pancakes

mathking 19-01-2012 08:37

Re: Laying it all out there
 
1 Attachment(s)
For picking up the ball, you can take a window motor with one of the hubs and screw the hub directly into a piece of PVC pipe. Put a cap on the other end and a shaft through it and you have a nice roller. Here is a pic of our 2006 bot (with was before we started using round urethane belting instead of conveyor belting, but this conveyor was the one part of the robot that always worked perfectly) which used this set up. Looking back at the BOM, the PVC, the belting and the hardware to mount all of this was $85.

notmattlythgoe 19-01-2012 08:39

Re: Laying it all out there
 
Are there any other teams around your area that you could contact to get some additional help? If there are I'm sure they'd be willing to give you guys a hand since you are lacking in the mentor area.

fox46 19-01-2012 09:01

Re: Laying it all out there
 
I just googled your location- there must be a team nearby, at least in Knoxville who can help you. Try soliciting local businesses for mentors- even in a rural area there are very knowledgable individuals who should be able to help: machine shops, autoshops, general contractors small engine repair, even hardware stores should have some knowlegable people who could help. Heck- farmers! If they know how to run a combine harvester then they should have LOTS of ideas for a ball harvester!

The two teams I mentor are 3 hrs away from each other, one - 2013 Cybergnomes, is in a very rural area and their main sponsor is JT's Snowmobile - http://jtsnowmobile.com/ which is a snowmobile and ATV shop. This one amazing shop whose building started life as a hay shed, provides more support than I have seen from multi-national corporations supplying teams with thousands of dollars and engineers to help them! Let alone, the quality, innovation and talent that comes out of their town of Stayner Ontario is mind-blowing as the Boston regional last year will attest to. Just because you aren't in a rural area doesn't mean there aren't knowledgable individuals and businesses who are willing to help in your midst. You guys have to get out there and find them and I bet they would love to help you- sometimes all it takes is asking.

JaneYoung 19-01-2012 10:31

Re: Laying it all out there
 
Quote:

Originally Posted by Team 4264 (Post 1108805)
So legally (bag /tag rules) how is this possible at a regional event with lots of new rookie TN teams trying figure out what is going on?


I love this whole post. Thank you for laying it all out there. This is big. This is big because it is a wise assessment of the situation that impacts your entire region - not just your team. I spend years trying to crack that nut open with individuals and teams and it's great to see that a member of a rookie team - gets it. Wow. I'm going to talk about the competition, not the build. You have suggestions regarding build and I hope you continue to find help and support for your build season because you showed the courage to post and laid it all out there.

It's very difficult for a region to grow new rookie teams without a plan of developmental support in place. Recruiting teams and providing funding through grants, etc., is well and good but - where's the plan to help the teams succeed in the region that they are forming as a team? Texas grew lots of rookie teams over a very short span of time and not all of the rookie teams have thrived in their 2nd, 3rd, or 4th year. Because of their needs and their impact, it became very evident that support was absolutely essential in helping them to build sustainable programs and continue to develop into competitive teams. There have been some gains made but not as much as there could have been if they could have hit the ground running with a plan in place.

I was looking back at a thread that I had created after the 2011 Alamo Regional. In that thread, it is very clear that everyone pulled together to get the rookie teams through the event. From that thread and from my experience as a volunteer at the event, I have a few suggestions:

At the event, talk to and work with your Robot Inspectors. Immediately if not sooner. Many rookie teams have it in their heads that the robot has to be perfect before they go to inspection. Not true. For one thing, the robot is never going to be perfect. Establish communication with the inspectors and get the robot through the initial inspection process. That lets them know where the team/robot stands and it lets the team know what they've got to do to pass inspection. And - it gets the team on the map regarding help/support. The inspectors are aware of the status of the robot and they can direct help and support in the team's direction.

Don't turn down help. It's an opportunity to benefit from the experience of other teams. It's an opportunity to see how other teams work - hopefully in a cohesive, efficient, and friendly manner. It will benefit your team.

Keep your pit area clean and with a place for everything and make sure your pit crew knows what that place is. (You can do this in your build space, too. Order will help the build process go more smoothly and cut down on wasted time.)

Find out what kind of tech support you have at the venue and where it is located. Find out where the practice field is and what kind of process is in place to use it: sign-up sheet, practice time, etc.

Last year's Alamo Regional had a lot of rookie and young teams. It also had veteran teams who stepped in to give support. Some of the teams that come to mind are:

FRC 148, the Robowranglers
FRC 1429, Team KAOS
FRC 2587, the Discobots
FRC 2468, Team Appreciate

The inspectors could contact these teams (and others) and let them know to help another team and what kind of help they needed.

We also had veteran teams who traveled in from out-of-state to compete in and support the event. FRC 16, Bomb Squad, out of Arkansas and FRC 245, the Adambots, out of Michigan. What that does is help stabilize and strengthen the event. The veteran teams are bringing their valuable competitive experience with them and sharing it with the younger teams. Some of that is direct - helping, assisting, offering suggestions, competing together on alliances. Some of that value is shared indirectly - the veteran teams role model how to work as team in order to compete well. They also role model how to conduct themselves as a team when things aren't going as planned or as well as they would like.

It's difficult to develop a region of rookie and young teams without the support of the veteran teams. We've all (veteran teams) been there, done that. We've all gone through variations of what you are going through now.

I'll share one last thought in this post:

Enjoy it. As hard as it is right now - enjoy it. Remember it. Document it. Use this year to lay a strong foundation to build on. You will only have one rookie year - celebrate it. This includes the hardship, trials, unknowns, and busted bubbles.

This wasn't a post with technical answers or advice but - you posted in the General forum so I felt that it was ok to post in your thread. Finish your build and then read this before you go to your competition.

Rock on 4264.
All the best,

Jane

Akash Rastogi 19-01-2012 10:36

Re: Laying it all out there
 
Go visit the U of Knoxville. If you need contacts from their engineering dept let me know.

Aur0r4 19-01-2012 10:59

Re: Laying it all out there
 
Team 4264,

Our rookie year was 2003 and we used castors and two driven wheels in the back...ours worked great! Its not the best drive system, but it does work, its cheap, and that year our torquey drive system allowed us to make Semi-finals at GSR because we 0wned the slick ramp. Keep it geared low and you'll be fine. If you want to climb the median, some 8-10" bicycle wheels on the back should allow you to climb over, maybe add some deflector plates around whatever castors you use. Ball casters (we used them twice) will do worse than regular castors on the median. Regular castors will twist to get over, but ball castors will likely get ripped off.

I would use a CIM motor on the ball shooter with direct drive. Certainly better setups, but our tests with a simple, one-wheel pitching machine and a CIM direct to the shaft worked pretty well. Put that bad boy on a jag and you should be able to score some points.

And I agree with the other teams, reach out to your local teams and reach out to your inspectors. Robot inspection is more stringent than bridge inspection (I build bridges, and its true) and yes, the process is iterative. The judges will help you, and getting a prelim opinion on the things you have to fix is a great strategy for anyone!

Good luck! Feel free to send me any questions,

Jim, EIT

zachmartin1806 19-01-2012 11:36

Re: Laying it all out there
 
I highly recommend you go and watch 1114's Kitbot on Steroids presentation, the configuration can be set up for a narrow or wide side pick up and uses nothing but the kit of parts. Trust me it works very well and fairly easy to program (as far as programming goes). If you need anything don't hesitate to ask the CD community, you will get many great answers. Good luck this year! :D

mlantry 19-01-2012 12:25

Re: Laying it all out there
 
in my opinion as a new team create just a kit bot but give it the ability to go over the bridge and practice balancing so u get points. and get 2 more cims to make a better drive train

EricH 19-01-2012 12:27

Re: Laying it all out there
 
Quote:

Originally Posted by mlantry (Post 1109043)
in my opinion as a new team create just a kit bot but give it the ability to go over the bridge and practice balancing so u get points. and get 2 more cims to make a better drive train

A lot of other people prefer that rookie teams at least take a shot at doing something other than just being a brickbot that plays defense. Which is exactly what these guys are doing: trying to get a scoring mechanism going.

Jeffy 19-01-2012 12:56

Re: Laying it all out there
 
Build the kit bot (for drive). Simple, easy, effective.

RogerR 19-01-2012 13:38

Re: Laying it all out there
 
Quote:

Originally Posted by Team 4264 (Post 1108805)
...

4264,

Check your private messages; We might be able to help you out.

-roger

Alex.q 19-01-2012 16:12

Re: Laying it all out there
 
Quote:

Originally Posted by squirrel (Post 1108813)
You can probably get by with a single motor/wheel shooter, have the ball go over the wheel, that will give it backspin and make it more likely to land in the basket. One FP motor is sufficient, and you probably want a single stage of gear reduction...see if you can modify the plastic FP gearbox to do this. We've done it by just using the first plastic gear stuck in a box we made ourselves, but without some machining help it would be pretty difficult. See if you can find any kind of machine shop that might help you

We are considering using the plastic FP gearbox (for our collector) because one of our mentors thinks it will be easy to connect to PVC. Did you actually use the gearbox or did you just cannabalize it for the gears, and if you actually used, could you give me some feedback on how to interface into the gearbox's input and output? (or alternatively tell me that if its a bad idea)

Siri 19-01-2012 20:48

Re: Laying it all out there
 
Quote:

Originally Posted by fox46 (Post 1108939)
Just because you aren't in a rural area doesn't mean there aren't knowledgable individuals and businesses who are willing to help in your midst. You guys have to get out there and find them and I bet they would love to help you- sometimes all it takes is asking.

One of our Hall of Fame teams, Cybersonics (103), also runs a FIRST rural support network. I bet they'd also be happy to help you out in whatever ways they can. They're in Pennsylvania (a town 60% the size of yours, actually), but they're an amazing team in all aspects and have built up an astounding resource network and knowledgebase.

Dancin103 24-01-2012 10:34

Re: Laying it all out there
 
Quote:

Originally Posted by Siri (Post 1109359)
One of our Hall of Fame teams, Cybersonics (103), also runs a FIRST rural support network. I bet they'd also be happy to help you out in whatever ways they can. They're in Pennsylvania (a town 60% the size of yours, actually), but they're an amazing team in all aspects and have built up an astounding resource network and knowledgebase.

Siri,

Thank you very much for all of your compliments. :) I will PM the team in need to see where we can help. To anyone in need of help in anyway, rural or non-rural, please let me know. FIRST is the hardest fun you will have and we are always willing to help. :)

Cassie

rsisk 24-01-2012 16:30

Re: Laying it all out there
 
Don't forget that scoring on the bridge can bring your alliance 10-20 points if on your alliance bridge or up to 2 Qualifying Points on the co-op bridge in the center, so even without a ball scoring mechanism, just getting up on the bridge to balance has a lot of value.

DonRotolo 24-01-2012 21:00

Re: Laying it all out there
 
Quote:

Originally Posted by Team 4264 (Post 1108805)
Legend tells of a bot from rookies of the past brought in with no programming to compete yet the kind competitors swooped in and saved the day by programming it before the event.

Well, yes, it happens all the time, but let's try to avoid as much of that as possible while there is time.

BUT: If you do show up at competition without a fully-functioning robot, ASK FOR HELP IMMEDIATELY. Teams will be tripping over each other to help you get up & running.

You might be happier with a 4-wheel system, using chain to drive the back wheels from the same motor as the fronts. But we did use ball casters one year, it wasn't awful, but our drivers had to practice a lot to get good at it. Oh, and they get gunked up a lot, clean them after every 2-3 matches.

Don't diss those FP motors, they sure do look wimpy but they're very powerful. But if you stall them (apply power while the shaft can't move) they'll let out the magic smoke very quickly.

Keep asking ANY and ALL questions here on CD. All of us are problem solvers for fun, and we'd love to get a shot at solving yours.:D

Al Skierkiewicz 24-01-2012 21:50

Re: Laying it all out there
 
Team,
I only have a few minutes so I haven't read all the posts if this has been stated already. If you have any plans of going onto the bridge, casters are the worst thing you could try. While they could be made to work OK on flat floors you cannot control them on a sloped surface. Teams have ignored this warning in the past so I will tell you that once you find the casters a burden, you can fix the position of the wheel. Just drill a hole through the plates of the caster, insert a screw and nut to lock the rotating pieces and turn the casters into non-rotating wheels. We abandoned casters in '98 and that played on a flat floor, never to be resurrected.

tcjinaz 04-03-2012 13:39

Re: Laying it all out there
 
Quote:

Originally Posted by Team 4264 (Post 1108805)
Well, so far you guys have really busted our design bubble about the FP motors so I'm just going to lay it all out and see what you think. Let me remind you that we are the rookie rural school with absolutely no help. No mentors, no engineers, no clue, no time, and not enough students (4-6 regulars), but we are going to build a bot!
<snip>


You must regale us now with the story of your run to the FINALS!!!
Congradulations. Hope you had a great time.


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