Adapting robot to meet <R16> (was: WE NEED HELP)

hi
we put our robot together and found out it was too big(the 80 in rule got us)
so we need help
we ship in less than 10 days and practically no way to grab the ball

we have a 5 foot robot with an upright staionary “shoulder”
we have a 50 in “arm” that extends from the top of the “shoulder” out. it can move up, down, and around our “shoulder” and thats pretty much it
we had a claw mechanism that had circular claws but didnt work b/c it was out side the 80in

we have one idea, but its a last resort kind of idea

we pretty much ran out of ideas, and the idea we do like, its too late for them
if anyone out there has any suggestions or tips on what to build, or anything
WE NEED HELP!!

  • team 270

Can you shorten your mast and/or arm?

either send me pictures via pm or email or post them here. we have a similar arm set up so i can help you out with that.

i will be back online in the morning tomorrow.

It’s not that hard to get around the rule, just need some work on the gripper and programming.

post up some pics and i will try to help to

just post some pics and everyone will help
good luck

Like Alex Cormier said, we’ve been working on a team with a similar looking robot to the one you’ve described. Of course we could help a lot more with pictures, but I’ve done a lot of the “math” regarding our robot and the 80" rule on graph paper with a calculator.

Basically, what I did for my team’s robot was that I looked at a top view of the robot and drew it to scale on graph paper. I took the back corners of the robot’s bumpers and with my compass I drew two 80" circles extending out from each point. With that, you can draw in the length of your arm in the position it would extend from the robot. From there, it’s pretty easy to figure out how much room you have in front of your robot for a claw mechanism. (Taking into consideration claw width at all times)

Then you can go draw a side view. Consider the arm and the claw two sides of a triangle. If the distance of the “hypotenuse” of the triangle is fixed, you can make it so that the reach is never longer than say… 80 inches from the back of your robot. An alternative if you have seasoned programmers is to fix the angle of that arm in the program…

Once that angle is calculated you may find that you have to change a bit of strategy or design.

You may shorten your arm, have to pick the ball up from the top, may have to pick the ball up and turn around and throw it “over your shoulder” to hurdle. This rule is tough, but I’ve found that with a little calculations and time and a lot of eraser marks, you can make a design like this work.

You can always PM me if you need any additional explanation or help.

Another thing to consider is that the matches are played with alliances of 3 robots, and there are only 2 trackballs for each alliance, so in any one match, one robot on each alliance probably won’t be able to hurdle anyways. So if you build a very reliable robot that can make fast laps and play strong defense, and perhaps knock the ball down and herd well, then you have a good chance of being in the tournament on Saturday.

Hurdling is not necessary, it’s optional, and if you find that it is taking most of your time to figure out how to do it and you’re not getting the robot built, then it might be wise to give up on that part of the game and concentrate on the other parts.

In our rookie year 2006 we built a robot that could not shoot balls into the high goal, yet we were the alliance captain for the winning alliance at a regional!

sounds like you have the start of this design

I know of a few teams building something similar to this. It should be an easy implimentation from where you’re at now

Can you post a picture or drawing? Don’t panic because everyone here will help you guys/gals out.

Is the pivot point of your arm over the center of your robot or over one of the ends?..

If we see it we can help… Are you using pneumatics on your robot already?

We need to see how your robot is set up…
Dimensions and locations for your pivoting arm… How high?
What motors so we know what you can lift… ?? How is it geared…

Hope to see more!!!
I think we would all like to help…

There’s a photo of their robot on their website.

http://team270.org/myPictures/E69CF69B70.jpg

How long was your proposed claw design? Did it have a “wrist” to allow it to fit in the starting configuration? And finally. Do you really need to extend your arm that far to persuade the ball over the overpass?

By the way, you have PLENTY of time left, I normally don’t start stressing until the final week. It’s better to realize it now then just before you ship. (rebuilding mechanisms at your first regional is never fun)

I would say the arm is currently too long, after seeing the picture. You could probably shorten it and still hurdle.

Indeed, we recently discovered that our arm could still hurdle with the wrist being only 71" high. You may find that your arm performs similarly.

thank you “M. Krass” for putting the link up to the site, i was just so busy w/ trying to figure out what we were going to do
we have an idea with putting up an elevator system
but incase that doesnt work, ideas and thoughts are welcomed
thank you to all the teams who suggested and helped

-team 270

Tilt your mast back and shorten your arm.

If you can spare the weight, consider using pneumatics to shorten and lengthen your arm to fit size requirements.

lean the mast back afew degrees (trig will help you figure out the optimal lean)
and shorten it up abit.