Arm and grabber design test video

[Rangel(kf7fdb)]

Originally Posted by squirrel

I like it! is there any special coating/material on the bars that grip the tube? or does geometry make it work?

Right now there is currently double sided tape on the bars but we are planning on using this cell phone cover material that is sticky but not sticky. I am not really sure how to explain it.

[MrForbes]

Oh, like the stuff on the back of Steve's phone?

[Rangel(kf7fdb)]

Originally Posted by squirrel

Oh, like the stuff on the back of Steve's phone?

Yes, and the sticky and rough material on the phone is now called "stuff".

[Stephen of REX]

One time I was at a convenient store and there was a little display for a no slide cell phone pad. It was inclined at something like 45 degrees and you could rest a cell phone on it without it sliding off. Truly miracle material like this would make for a successful manipulator.

[SteveJanesch]

Thanks for posting, Fredi. I love your prototyping methods. Any thought to how to pick up the logo pieces in auton? We had a couple wrinkles to iron out in Rack 'N' Roll having to start inside the 28x38x60 envelope (with our gripper closed) and the game piece touching the robot - we had to push the tube away first, then drive forward, pick it up, then finally approach the rack. Or will you be able to hold the ubertube in the gripper at the start of auton?

- Steve

[MrForbes]

this stuff?

http://apps.facebook.com/ecwid-shop/store/43090479006

or if that doesn't show up where you are,

http://www.egrips.com/

[falconmaster]

Originally Posted by SteveJanesch

Thanks for posting, Fredi. I love your prototyping methods. Any thought to how to pick up the logo pieces in auton? We had a couple wrinkles to iron out in Rack 'N' Roll having to start inside the 28x38x60 envelope (with our gripper closed) and the game piece touching the robot - we had to push the tube away first, then drive forward, pick it up, then finally approach the rack. Or will you be able to hold the ubertube in the gripper at the start of auton?

- Steve

We might work on that soon....

[MrForbes]

The NERDS 2007 robot has a "wrist" joint that let the claw (with a tube loaded in it) flip down and extend out at the beginning of the match. I seem to recall it took a lot of planning and a bit of luck to make it work. We're thinking of a similar concept again, but possibly a telescoping action instead of hinging?

[Al Skierkiewicz]

Fredi,
If only more teams follow your lead for design. Think, prototype, think some more, prototype some more, think and design. I am always impressed by your team. Nice job.

[falconmaster]

Originally Posted by Al Skierkiewicz

Fredi,
If only more teams follow your lead for design. Think, prototype, think some more, prototype some more, think and design. I am always impressed by your team. Nice job.

We don't always have the money to just buy our way out so we have people argue their points to convince the rest of us, then we buy, buy, buy!

[jamie_1930]

prototyping at it's finest.

[nick_champ_2]

I like it, though just through watching the video, you have the arm closing at the exact time that the bottom of the "gripper" touches the tube. This should be tried in a more realistic situation where the bot will drive past or push the tube while closing the "gripper". That way you can verify that the gripper will grasp the tube as it is being pushed away.

Just a thought. We are going to be working on a complex arm starting today!!!!

[Zach Purser]

Originally Posted by nick_champ_2

I like it, though just through watching the video, you have the arm closing at the exact time that the bottom of the "gripper" touches the tube. This should be tried in a more realistic situation where the bot will drive past or push the tube while closing the "gripper". That way you can verify that the gripper will grasp the tube as it is being pushed away.

Or add a contact switch to the bottom of the gripper.