Robowranglers 2014: Vader

[Aren Siekmeier]

Originally Posted by BBray_T1296

If you are putting weight on a wheel that is not driving (Ie an omni wheel pointed sideways) that is weight that is not being put on the wheels that are driving. friction=coefficient*Normal, so the more weight on the HT wheels, the more traction, and thus the more pushing power.

While the /H/ leg of the drivetrain is not being run, those wheels are entirely off of the ground, thus they are not detracting from the weight on the traction wheels.

I'm willing to bet an even bigger reason was so they could still power slide with the strafe module off the ground.

[Abhishek R]

Originally Posted by Tom Line

Abishek,

It's impossible to have all the wheels touch the floor at the same time, because the floor isn't perfectly flat. As a result, there are times where a non-articulated center wheel will be lifting one side of the drive train off the floor, so that you end up going in circles when you try to drive forward.

I can't see the mechanism well, but I wonder if it doesn't use torsion springs to return it to level so it isn't touching the floor when it isn't running.

Electronica1: I'd venture a guess that your drifting hypothesis is correct. They've seemed to enjoy drifting - I remember them doing it quite a bit in 2011.

I see, thanks for the explanation.

[barn34]

I'm surprised I'm the first to go there yet, but....

Impressive. Most Impressive.

In all seriousness, another awesome job from 148, per usual. Hoping to see this Sith beast up close and personal at championships.

[roystur44]

Nice job,

How does the pneumatic controlled tensioning for the catapult work out? I see it's on a pulley. Do you get a good variation on a shot?

[Connor Mulkey]

You guys need to find a way to actually light up the intake rollers like lightsabers. I'm too attached to that image for it to be any other way. Get on that!

[DanielPlotas]

Originally Posted by dodar

Or rename it Darth Maul.

but maul had a double-sided saber, not two. i would suggest Ahsoka Tano, but i am no fan of the clone wars series.

[nxtmonkeys]

"known well, many jedi are not. secrecy they live in much."


-Yoda

















(not really, but it sounds nice, doesn't it? well, I'm trying to say that you could make up a new name if you wanted to.)

[RachelDoby]

Originally Posted by BigJ

Come now, we all know that in his time as Darth Vader he only used one lightsaber. I suggest one of the el toro arms be taken off.

We tried to intake with just one lightsaber. It doesn't work as well as we'd hoped.

The team was inspired by the look of the intake to create a Star Wars theme. After deciding on the design, we voted on the robot name. Thus, Vader was born.

Originally Posted by techtiger1

Really 148 went with that collector.

We were inspired by the BOOM DONE intake, El Toro. After testing lots of different intakes, we decided that this design was best fit for all of the things we wanted to accomplish. As you can see, we are not the only team that felt this way.

Originally Posted by lineskier

I noticed a rangefinder on the front of the bot. Could that be an autocatch feature?

Yes, the range finder is an autocatch feature. Our operator holds down a button when catching is appropriate, and when the balls lands in our cradle, the lightsabers close onto the ball to secure it.

Originally Posted by roystur44

Nice job,

How does the pneumatic controlled tensioning for the catapult work out? I see it's on a pulley. Do you get a good variation on a shot?

We have two surgical tubing settings, one normal, and one we refer to as "The Force". The normal one is when the cylinder is retracted, and for longer shots we "use the force".

[RachelDoby]

As for the questions about the choice of our robot name, we've never in the past committed to a Texas theme.

After seeing our intake design we decided as a team to do a Star Wars theme. So far this year, we're really enjoying all of the goofy things we are able to do with the name.

Certain team mentors have decided to veto any mention of... the other 3 movies.

[RachelDoby]

Regarding our drivetrain, Vader uses the next iteration of our articulating drivetrain, originating with the one used on our 2010 robot: Armadillo. In 2010 we used a drivetrain, referred to as the Nonadrive, that consisted of a five omni wheel H-drive, plus four traction wheels for optional pushing.

In the new iteration, the "Decadrive", we are using a Nonadrive with two center wheels instead of one. The two center wheels freely pivot about a gear that is powered by the CIMs. There are no separate actuators to move these wheels up and down, they are tilted by the drive CIMs. When the drive motors power it one way, the wheels pivot, such that when one wheel contacts the ground, we are able to strafe sideways.

The cool thing about this drivetrain is that when the center wheels are not in use, they don't touch the ground and as such do not interfere with the normal forward-backward driving (and they don't get in the way of our sweet power-slides). However, when one side one the module is dropped, the wheel digs in and tries to force itself downward, thus lifting up the robot, and allowing us to easily crab across the field.

Depending on which way the drive motors move, it drops the wheel which will naturally want to "dig in". We think this is pretty cool.

[lukedude43]

Out of curiosity, how much force is that surgical tubing generating?