CD 47 Edition 2007

[Andrew Blair]

Originally Posted by Mike Martus

Like most of the robot it is made of Alum tubing inc, the surface that is alum perf. Very thin, very light and very strong ( I hope).

We tested by using a 200+ pound person walking up and down the ramps ( a robot will never put that amount of force per sq inch).

Haha, except on entry...

What size hole, thickness, and alloy are you using? We're covering ours with 3/16" diameter hole, .05" thick, 3003 sheet from Mcmaster, with a similarly braced ramp. It feels good to me, but we'll find out I guess.

[Josh Murphy]

Originally Posted by Henry_Mareck

how much does your entire ramp system weigh?

One ramp assembly weighs roughly 16.5 lbs, so for both assemblies it weighs about 33 lbs.

[Josh Murphy]

Originally Posted by Mr MOE

Mike:


Very nice! What is your ramp material made of?

Also adding to what Mr. Martus said, this is our practice robot so it looks shinier because we have polycarb under the perf metal, The competition robot does not. yep weight issues!!!

[WillItBlend]

Looking good! We wanted to add ramps until we noticed our gigantic arm is in the way lol.

[TheNotoriousKid]

that is a great ramp...simple...and looks easy to get on,,,,,,,,nice

[Josh Murphy]

Originally Posted by TheNotoriousKid

that is a great ramp...simple...and looks easy to get on,,,,,,,,nice

Thanks, Yes it is a very simple mechanism, and it is easy to get on.

[petek]

Your ring grabber must be feeling pretty lonely with no one paying any attention to it, but I think it's pretty interesting. Is it automated, or does the driver have to run all the actuators separately?

[Josh Murphy]

The driver does do all the driving. There are limit switches that help the driver out a little bit and there is a pot that we can view the value on the OI.

[petek]

Originally Posted by Josh Murphy

The driver does do all the driving. There are limit switches that help the driver out a little bit and there is a pot that we can view the value on the OI.

What motion/axis is the pot feedback for? I think using OI feedback is a good idea for troubleshooting, but do your drivers find it useful in competition, too?

[Josh Murphy]

Originally Posted by petek

What motion/axis is the pot feedback for? I think using OI feedback is a good idea for troubleshooting, but do your drivers find it useful in competition, too?

The pot feedback is for the position on the arm. It allows the programmers to put in dead zones, which are very helpful, and it allows us to know when we are in position to grab a tube. Plus we have what is called "Gas Mode" which is for the case that the programming goes bad or something for some reason, which allows the drivers have complete control and have no stops or any limits on any of the motions, so yes reading the pot is very useful to the drivers.

[meaubry]

Hi Pete,

The ring grabber that you inquired about is pretty much automated, but the arm operator needs to coordinate opening the device with lowering the trolley.

The trolley is what allows the arm to move up and down a mast, as the motor walks up and down a chain. The bucket is hinged and opens and closes using a mechanism attached to a rack, which is driven by the window lift motor. At a specific point in the rack travel, the bucket is articulated open.

So, the arm operator simply locates overs the tube, and while lowering the trolley they push a button to drive the rack motor. While the tube pusher moves away from the tube, the bucket opens to clamp against the inside part of the tube. There is a switch to shut off the motor at the end of both the open and close travel positions.

The bucket also acts as a guide when aligning with the rack spider leg.

It didn't take the arm operator long to attain the skill to get really good at grabbing the tubes.

Mike