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-   -   [FTC]: Lift systems/Time? (http://www.chiefdelphi.com/forums/showthread.php?t=100554)

jasonbrooks 19-01-2012 22:56

Re: [FTC]: Lift systems/Time?
 
From our experience reading and doing research the past few years, the lego pneumatics are nowhere near powerful enough to do anything like this.

Andrew Remmers 20-01-2012 00:29

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by team F.T.C 4240 (Post 1109466)
I think you can use lego pneumatic's

Yeah... But... Those are kind of lame.

team F.T.C 4240 20-01-2012 08:06

Re: [FTC]: Lift systems/Time?
 
Better then nothing. And you could use a ton of them and pump them up with a bike pump before every match.

PhilBot 20-01-2012 14:41

Re: [FTC]: Lift systems/Time?
 
Hi teams.

For the record... G-FORCE only uses one motor for it's lift, and we've demonstrated a two-crate 86" lift in 4 seconds.

For anyone starting a new lift design, I recommend NOT trying for a hail-mary 10-section lift idea. The forces required to start the lift are magnified by each section you add, and rubber bands will only help if you want to launch the balls into the air. If you want to be successful, start with a few segments (eg: 4) and get that working, and then add some weights to see how much more it can lift. Then if you have power to spare, add segments.

As for defensive strategies... sure, you need them some times, but two purely defensive robots on an alliance will never score any points. I'd focus on teamwork strategies to help your partner score more.... maybe helping to collect crates with balls so they can lift them. Focus on at least one scoring method.

I was laso amazed to see how many rookie teams had not even tried to roll the bowling ball. You don't have to get it up into the goal to score 20, just roll it over to the ramp in end-game and sit there.

alphadog0309 21-01-2012 21:44

Re: [FTC]: Lift systems/Time?
 
Our previous robot design was completely powered by rubberbands and "held back" by a motor which would release it when necessary. We were able to reach the 8th level with 1 basket but chose to change our design because we were unable to bring our scissor lift back down with the power of the motor.

PhilBot 22-01-2012 09:53

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by alphadog0309 (Post 1110870)
Our previous robot design was completely powered by rubberbands and "held back" by a motor which would release it when necessary.

I stand corrected... Using the motor to brake the lift's motion is a good way to deal with rubber bands, but it did move the power problem to the other end of the motion.

Of course it's OK to use human power to bring the lift down again, but you probably discovered that it's quite a bit of force to apply.

What does your "new" design do?

alphadog0309 22-01-2012 23:09

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by PhilBot (Post 1111074)
I stand corrected... Using the motor to brake the lift's motion is a good way to deal with rubber bands, but it did move the power problem to the other end of the motion.

Of course it's OK to use human power to bring the lift down again, but you probably discovered that it's quite a bit of force to apply.

What does your "new" design do?

It took QUITE a bit of force (one almost-adult, male team member using all the force he had to push down while running the motor backwards to spool up the rope)

I am not currently at the liberty to talk too much about our most recent design but it uses an ACME threaded rod for movement along with the aid of rubber bands. It does go both up and down, which is a step up, and is very quick to lift. :)

PhilBot 23-01-2012 09:26

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by alphadog0309 (Post 1111598)
I am not currently at the liberty to talk too much about our most recent design but it uses an ACME threaded rod for movement along with the aid of rubber bands. It does go both up and down, which is a step up, and is very quick to lift. :)

Cool. Learning how to build a linear actuator is a great project.

jasonbrooks 23-01-2012 10:58

Re: [FTC]: Lift systems/Time?
 
Even though we successfully created a stacking robot, we have decided to completely redesign our bot and strategy as stacking was just not getting enough points (even though we are using it at our regional competition next week at PACE University).

We have successfully created a linear lift. Currently, it goes up around 156", but we still have room to expand more!

PhilBot 25-01-2012 09:56

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by jasonbrooks (Post 1111829)
We have successfully created a linear lift. Currently, it goes up around 156", but we still have room to expand more!

That will be fun to see.

PhilBot 25-01-2012 10:00

Re: [FTC]: Lift systems/Time?
 
Quote:

Originally Posted by h3x (Post 1108684)
Do you think FIRST meant for this game to be based around lifting? It makes all other scoring methods mostly useless.

Well, in my mind there can't be any question that this is EXACTLY what first wanted...

Lets face it... if you stack the maximum of 6 crates you can only get 36" high. What does the rules manual show for point scoring?

a. 0 < H ≤ 10.5” (26.67cm) scores 0 points
b. 10.5” (26.67cm) < H ≤ 16.5” (41.9cm) scores 10 points
c. 16.5” (41.9cm) < H ≤ 22.5” (57.2cm) scores 20 points
d. 22.5” (57.2cm) < H ≤ 28.5” (72.4cm) scores 30 points
e. 28.5” (72.4cm) < H ≤ 34.5” (87.6cm) scores 40 points
f. 34.5” (87.6cm) < H ≤ 40.5” (102.9cm) scores 50 points
g. 40.5” (102.9cm) < H ≤ 46.5” (118.1cm) scores 60 points
h. An additional 10 points for every 6.0” (15.24cm) increment above 46.5” (118.1cm)

How else could you get above 46" without lifting....
If they didn't want us to lift they would have capped at some arbitrary level.

JohnFogarty 29-01-2012 13:10

Re: [FTC]: Lift systems/Time?
 
I'm waiting to see a team stack ontop of one of those lifting robots.
Team 1102 has a linear actuator system on their robot. it can successfully stack and lift said stack without a problem. It's not a scissor lift but given a tall enough stack I think lifting 6 crates up 36 inches should get enough points.

bpddpb 08-02-2012 21:31

Re: [FTC]: Lift systems/Time?
 
My team (4299 Battery Powered Picklejar Heads) has gone for a quite unique strategy: everything BUT crates. We score magnet balls, the bowling ball, and have a cool autonomous program. This way, we can avoid the consistency problems we've seen with the all or nothing crate lifting strategy.

Plus, since balls (and magnet balls) go everywhere on the field, we can go picking up and sorting through balls while protecting our alliance or playing defense.

JohnFogarty 08-02-2012 23:32

Re: [FTC]: Lift systems/Time?
 
I personally think in the end Global Force is going to end up doing that as well. The lifting of crates with our current manipulator is a bit...."sad".
We can more than likely make it thought the SC Championship with what we have..but I'm not hoping for much more than that. Though I must say our magnet finding is pretty boss. It's my favorite part.

bpddpb 09-02-2012 23:08

Re: [FTC]: Lift systems/Time?
 
Do you have a really fast way of picking up balls or something?


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