Team 1107B 2011 Gateway Season 1 reveal

thats a good thing is it not? my first robot this season (if you can remember it) with the one 269 on each side of the lift had that problem… you had to kinda mush it down to keep it down at the start and hope it didnt pop up

yeah, but i think the “best” combination will be when its perpendicular to the ground with only tension (unhooked motors)
that way the energy required to lift up the the same as pushing down 50/50
its much better than say 30/70

Which programing does your team use? EasyC or RobotC?
Why does your team prefer it?

In theory, it is possible to have a perfectly balanced arm (constant mass) at all positions.
It takes an caroid shape cam (although an off-center mounted sprocket is close),
to trade energy in the rubber-band-spring for mgH potential energy in the position of the arm. When the energy tradeoff matches, the force can also be made to match.
In all the robots I’ve seen locally and at two world competitions, I’ve never noticed it done perfectly. With a good Notebook write up, it seems like a good candidate for Think award.

For a non-constant mass arm, such as gateway, where generally you are pickup cargo at the ground level, and lifting it high, you’d want to balance the arm including the usual amount of cargo. This also means an empty arm will be easier to lift than to drop down.

In other robot applications, you can use stuff like constant force springs and gas pistons to take load off DC motors, but in Vex, you’re pretty much limited to rubber bands and surgical tubing.

we use easyC because thats what we began with a few years ago and we are now very familiar with it and can code quickly with it.

hmm, do you have some sort of illustration of what you are describing?
im assuming its some complicated thing with elastics, but i could be wrong

I love your autonomous routine. Very amusing to watch your friend run around to catch the robot.

yep :smiley:
autonomous is now a “sport”
you should see our 1 min routine (posting soon), at one time, i actually have to RACE the robot across the field :wink:

Does anybody want to keep a count of how many times our autonomous routine is referenced in a Q&A thread?

Also, stay tuned for possible coming update (maybe next week?).

welll it would be really nice to know if what you have been doing is legal or not…

Good use of the polycarbonate.

Spring Arm perfectly balanced comments:

I started a new thread for this discussion, with a picture of a simple arm.

This shows the simplest example of an arm with elastic balance at one point.
Next step is to show the modifications necessary to get good balance at all points.

well we DID analyze the rules thoroughly before we even started coding the autonomous

thanks, we cadded everything and prototyped with cardboard before we cut the first piece of lexan :slight_smile:

What they are doing IS legal because they have a zip tie constantly touching the ground.

I know this is really old, but do you still use the VEXNet upgrade for crystal?? Is it as reliable?

WOW, i thought i was trippin out for a sec :stuck_out_tongue:
yes we do :slight_smile:
i think we are the most ghetto team ever! :slight_smile:
we use the vexnet upgrade with the pic
we use the oldstyle HUGE controllers
and we still use 3-wire motors everywhere! :slight_smile:

why fix if it aint broke eh? :wink:

Gah! I’ve been looking for one of those FOREVER! Haha, and ghetto teams for life. If you saw pictures of our C team (me), I had to scavenge our room for supplies. 3 wire motors, regular screws in the shaft collars. You don’t know anyone who still has the VEXNet upgrade willing to sell it? We can’t buy another VEXNet brain since we actually lost our sponsorship from the Department of Defense because they went over budget. (Maybe we shouldn’t have bought 5 new computers…)

(thread necromancy)

We use the old system: Mostly 3 wire motors, PIC with VexNet upgrade. Of course we’ve switched over to HS motors and 3000mAh batteries, but those are straight upgrades.
We’ve actually maxed out the capacity on the PIC at 32000 bytes for our program exactly.

Ack, beaten to it.

Wow, how many lines exactly?

And yeah, I always kill my PIC because I don’t have a power expander, and with the drivebase C team has, it needs one.