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-   -   Rookie Team, Any Advice? (http://www.chiefdelphi.com/forums/showthread.php?t=132593)

PurpleTurkeyHat 11-01-2015 12:04

Thanks everyone for your advice! I'll definitely be passing all of this on to my team!

popnbrown 11-01-2015 20:27

Re: Rookie Team, Any Advice?
 
Everyone else had really good advice, but I really only have one major one.

Be creative, feel free to think outside of the box tote! and Have fun! It seriously is the hardest fun you will ever have.

Mrcope9 11-01-2015 21:47

Re: Rookie Team, Any Advice?
 
Aside from the general design/build/programming advise, it's important to keep in mind some other important components:

1. Stay calm. Your patience will get tested and you will go through the same rookie struggles as everyone else. They are a part of life.
2. Keep your head up. It will get better. Just think ahead to 3 or 4 years down the road when you have the experience under your belt.
3. Have an open mind to all sorts of ideas. Every team will develop their own style.
4. Make sure to have fun with it, because it's a blast:D

GeeTwo 12-01-2015 00:19

Re: Rookie Team, Any Advice?
 
Quote:

Originally Posted by Zebra_Fact_Man (Post 1425949)
- Use the KOP frame. It's actually really good.

Everything I've read here is spot on. Get local help. Keep it simple. Have a project plan. Finish far enough in advance of bag-and-tag to have some driver practice. Consider designs "not invented here". Keep everyone working on something useful. Build field elements. Go COTS (Commercial off-the-shelf) whenever you can afford it.

I'll go on a bit more detail on the chassis and materials and strategy about strategy:

We used the KOP chassis our rookie year and again this year. We opted out of the KOP chassis the other two, and in both cases we would have used the KOP as a starting point and modified in much less time and headache than we had. Remember is to think any changes to the chassis through before you pick up a saw or drill. Our rookie year was Rebound Rumble where you had to pick up nerf basketballs, and we cut open the front of the chassis to bring them into our feeder. We never did get the frame square again!

Watch the weight limit. That slotted extrusion is great for prototypes, but it just gets too heavy for competition. We use 1/8" aluminum stock for most of our framing and 10-32 bolts to hold it together, with steel angle braces from the hardware store at junctions which must stay square.

Use hex shafts for your gearboxes and other shafts if you can afford it - we've lost several matches and many hours due to missing or lost keys. Buy twice as many shaft collars as you think you'll need - at $4 a pop, you don't want to have to wait for it to be shipped to you at the last minute. Buy spares. High-end teams run their motors and parts hard, and need to have enough spare parts on hand to build two more robots, but most teams can only manage about a quarter of that, so we have to be more careful.

Do the math. Find someone who can read a motor performance curve and understands a gear ratio - two would be even better. Use the motor calculator and other resources on this forum. If you can't figure it out, or want someone to check your math, start another thread here - it's a rare question that doesn't get a useful response within a day, especially during build season. Story: Our rookie year, we built a device to push down on a field element (bridge) that was underpowered by about a factor of ten because no one calculated the weight of the bridge until we got to our regional and it didn't work. We also built a ball launcher that could throw a ball full-court, but never put one in a hoop because we reached WAY too far in finesse.
Don't use pneumatic pistons for something that needs to stop at various points along its travel. It's possible, but you could work weeks getting it right the first time. Don't use a motor to hold something in place; motors are designed to spend most of their time running fast at fairly low torque. Figure out how much current you'll draw with each motor and other device to make sure you won't trip that breaker, or the main at 120A. The standard compressor is designed for a 7% duty cycle - if you're running it much more than that, find another compressor with the same cfm rating, but a higher duty cycle. Assign a battery manager - without fresh batteries, robots brown out, causing computers and other parts to shut down.

READ THE RULES! After you have a design, read the rules again to make sure you're in compliance. Any time you come up with a strategy that you intend to use, check it against the rules.

If you're in a regional that isn't the first week, watch some video the first week or two. See what does and doesn't work, and you may decide to adjust strategy before your regional. You may also find out that some of the rules are being judged differently than you read them. For example, we read the rules last year (3.1.4 C)
Quote:

A BALL is considered SCORED in an ALLIANCE’S GOAL if
A. a ROBOT causes one (1) of their ALLIANCE’S BALLS to cross completely through the opening(s) of one (1) of
their ALLIANCE’S GOALS without intervening human contact,
B. the ALLIANCE ROBOT last in contact with the BALL was entirely between the TRUSS and their ALLIANCE’S
HIGH GOALS, and
C. the BALL is not in contact with any ROBOT from that ALLIANCE.
to mean that pushing the ball into the goal at ground level did not count as the ball was in contact with the robot as it passed through the goal. It did count; I can only presume that A and C were intended to be sequential rather than simultaneous.

SoftwareBug2.0 12-01-2015 00:51

Re: Rookie Team, Any Advice?
 
Quote:

Originally Posted by GeeTwo (Post 1426555)
Don't use pneumatic pistons for something that needs to stop at various points along its travel. It's possible, but you could work weeks getting it right the first time. Don't use a motor to hold something in place; motors are designed to spend most of their time running fast at fairly low torque. Figure out how much current you'll draw with each motor and other device to make sure you won't trip that breaker, or the main at 120A. The standard compressor is designed for a 7% duty cycle - if you're running it much more than that, find another compressor with the same cfm rating, but a higher duty cycle.

I agree with almost everything you said except for the pneumatics.

We've had good luck with pneumatic pistons that need to stop at locations other than the ends. In our 2005 robot we had an arm that was raised and lowered to various heights by a single huge pneumatic cylinder, and it took no special programming or driver practice to control. We were also happy using an intermediate location to aim our 2013 robot. I think they're easier to write software for than a motor because they don't burn out when you tell them to do the wrong thing.

Also, I think most teams can safely ignore the pump duty cycle ratings. Matches are short.

GeeTwo 12-01-2015 01:03

Re: Rookie Team, Any Advice?
 
Quote:

Originally Posted by SoftwareBug2.0 (Post 1426574)
We've had good luck with pneumatic pistons that need to stop at locations other than the ends. In our 2005 robot we had an arm that was raised and lowered to various heights by a single huge pneumatic cylinder, and it took no special programming or driver practice to control. We were also happy using an intermediate location to aim our 2013 robot. I think they're easier to write software for than a motor because they don't burn out when you tell them to do the wrong thing.

We struggled with this last year. Plumbing a solenoid valve as described in the tutorials gives you a cylinder that is always pushing one direction or the other; it won't stay still. We managed something with two separate valves which worked, but it never really stopped; it always drifted one way or the other. But yes, when you can use them, they are much more predictable, consistent, and self-limiting.

SoftwareBug2.0 12-01-2015 02:49

Re: Rookie Team, Any Advice?
 
Quote:

Originally Posted by GeeTwo (Post 1426583)
We struggled with this last year. Plumbing a solenoid valve as described in the tutorials gives you a cylinder that is always pushing one direction or the other; it won't stay still. We managed something with two separate valves which worked, but it never really stopped; it always drifted one way or the other. But yes, when you can use them, they are much more predictable, consistent, and self-limiting.

Interesting; I didn't realize there even was a pneumatics tutorial. It's too bad it's so elementary. I wonder if there's a good resource to recommend to teams for more advanced techniques. Maybe I should write one. (No promises though, and it would not be done before the end of build season anyway)

JosephC 12-01-2015 06:45

Re: Rookie Team, Any Advice?
 
If you haven't yet, take the time to sit down with your ENTIRE team, that's right, every student and mentor no matter what group they belong to, and read the ENTIRE rulebook together, outloud, preferably on a large screen. Take the time to answer any and all questions regarding any rule.

It may seem like a big waste of time, but in the long run, every member of your team knowing every rule inside and out, is going to save you a lot of headache during the build season. 68 did this every year I was on the team (and I'm sure they still do) immediately after the password was given out. It keeps students from designing illegal prototypes, and saves a lot of time during the build season answering the same rules question over and over again (it happens trust me).

Rosiebotboss 12-01-2015 08:24

Re: Rookie Team, Any Advice?
 
I just took a quick look at GOOGLE maps to see where New Albany, OH is. You have 5 teams in Columbus and 1 in Westerville. There may be others. You can find them here:http://www.usfirst.org/whats-going-on

And, contact Ted hood, your FIRST Senior Mentor....he can help. http://www.usfirst.org/community/vol...mentor-program


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