Robowranglers 2014: Vader
 

Re: Robowranglers 2014: Vader
 

Oh dude, sweet...

Re: Robowranglers 2014: Vader
 

Well...

*collects jaw from floor*

Re: Robowranglers 2014: Vader
 

Awesome job guys! Very well put together video as well!

Re: Robowranglers 2014: Vader
 

Really 148 went with that collector. :o

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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. ;)

Re: Robowranglers 2014: Vader
 

Or rename it Darth Maul.

Re: Robowranglers 2014: Vader
 

Very nice. It's always a treat to see the great production in your reveal videos.

Re: Robowranglers 2014: Vader
 

I have to ask, how does the articulation for the strafing wheel work (I noticed the 2 strafing wheels but it looks like they are both not on the ground at the same time)?:confused:

Re: Robowranglers 2014: Vader
 

Tumbleweed, Tornado, Armadillo, Raptor, Scorpion, Viper, Vader!? :D

Re: Robowranglers 2014: Vader
 

In awe!!

Re: Robowranglers 2014: Vader
 

I noticed that as well, why the deviation from the Texas theme?

Re: Robowranglers 2014: Vader
 

Raptor = Texas? Or Tornado? This isn't a deviation.

Re: Robowranglers 2014: Vader
 

Western, desert, desolate...Texas. ;)

Re: Robowranglers 2014: Vader
 

I'd also love to here a bit more insight about the strafe wheels and how/why the articulate between multiple wheels

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That shot at the end. I know that's going to be even more popular now.

Re: Robowranglers 2014: Vader
 

Me too, especially with the mecanum wheels at 5 seconds.

Re: Robowranglers 2014: Vader
 

That play in general will be a lot more powerful than people were thinking at the beginning of the year. If you have a human player that is used to it, you can get easy truss points and you won't lose control of the ball.

Re: Robowranglers 2014: Vader
 

Parts of Texas are in the area of the country known as "Tornado Alley." As for Raptor I think when they released it they said the name was a reference to the predatory birds, not the dinosaurs, also a feature in Texas.

Plus I believe in the past they've said their robot names have followed a Texas theme, but I may be imagining that.

Re: Robowranglers 2014: Vader
 

Those mecanum wheels are on a drive in a day frame, and I am pretty sure the final robot had omni wheels. Also, I think their frame has 6 sides unlike the one they had mecanum wheels on.

Re: Robowranglers 2014: Vader
 

Yeah, I believe you are correct. I'd be very interesting to hear from 148 about how this drive differs from their 2010, prior butterflies and a straight up mecanum and why they picked it.

Re: Robowranglers 2014: Vader
 

Ah, well this clears it up... :rolleyes:

Re: Robowranglers 2014: Vader
 

Ohhhhh. It totally makes sense now!

Re: Robowranglers 2014: Vader
 

Looking great guys!

It looks like the axle that the little two-wheel fork is on is also the axle through which the wheels are powered. As a result when the motors spin the fork rotates until it hits the ground. Once the fork can't go further down the wheels are forced to rotate by the same motor. If that is the case its a pretty cool system.

Off to watch the video some more..
Cheers, Bryan

Re: Robowranglers 2014: Vader
 

I am thinking the same thing, but I am having issues see how they are getting enough force to give the wheel traction because won't most the weight still be on the 4 outer wheels?

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Re: Robowranglers 2014: Vader
 

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

Re: Robowranglers 2014: Vader
 

So... I guess this means BJC was spot on. I just have to ask, why?

Re: Robowranglers 2014: Vader
 

This is awesome. I appreciate the early post. The subtle changes over the "BoomDone" robot are awesome and are clearly well thought out. Good luck this year!

Re: Robowranglers 2014: Vader
 

I spy a Day[9] shirt.

Re: Robowranglers 2014: Vader
 

I'd be amazed if any of the elite teams didn't plan on it from day one.

Great video, and great looking robot, 148!

Re: Robowranglers 2014: Vader
 

This team is where Rosie the Riveter gets her rivets. Anyone know how many are on this robot?

Re: Robowranglers 2014: Vader
 

I would put my money on detecting ball acquisition in auto.

Re: Robowranglers 2014: Vader
 

This is totally fake. Where's the secret endgame mechanism? I refuse to believe that 148 would ignore the point bonus that we don't know about yet.

Re: Robowranglers 2014: Vader
 

Anyone able to enlighten me on why the bowed out frame? I would imagine there's some reason...

Re: Robowranglers 2014: Vader
 

Care to share material is on the el toro?

Edit - added:

Btw nice job on the mechanism that "narrows" up the sticks while it lowers. Very slick and one of those things that you don't notice at first.

Re: Robowranglers 2014: Vader
 

Go to 1:24. it looks as if they have a high traction/mecanum drivetrain

Re: Robowranglers 2014: Vader
 

It depends on the angle of the fork. As the wheels turn, if they are geared correctly, they will actually try to walk down more under the robot and put additional force on themselves. Think of the way that a rear wheel drive car transfers weight to the rear when it accelerates. In this case you aren't shifting the robots weight, you're using the leverage of the drive to push down into the floor harder.

As to the why: every tried to get 5 legs of a stool all the same length? Articulating that wheel is necessary - pneumatically or otherwise. I'd guessing this is a way of not using more pneumatics.

We have a little bit of familiarity with a slide-drivetrain. We tried one in 2008 but we hard-connected the wheels to the frame and quickly discovered why you absolutely MUST have mechanical compliance to insure all the wheels are on the ground. What they have here appears to be a refinement of their 2010 drivetrain.

Re: Robowranglers 2014: Vader
 

:yikes: That makes so much sense.

Re: Robowranglers 2014: Vader
 

Could you expand a bit more on why the hard-connected version didn't work and why the center wheel must be articulated? It seems to me if you just had it dropped enough the hard-connection would work.

Re: Robowranglers 2014: Vader
 

I meant why as in why do this method over, lets say, spring loading it. I understand with H drive you want to have the center wheel always against the ground, however, my team's FTC team did an h drive with the center wheel drop a 1/16 of an inch and it worked pretty well. I am just curious about why use a "floating" center module rather than a spring loaded module? Was the reasoning so they could drift when the center motors were not running?

Re: Robowranglers 2014: Vader
 

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.

Re: Robowranglers 2014: Vader
 

Someone needs to let disney know that this robot will be in their movie. Not a question, a statement!:p

Re: Robowranglers 2014: Vader
 

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.

Re: Robowranglers 2014: Vader
 

Great job on the Robot and Video release!
I guess I'm late to the party.

Re: Robowranglers 2014: Vader
 

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

Re: Robowranglers 2014: Vader
 

I see, thanks for the explanation.

Re: Robowranglers 2014: Vader
 

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. :)

Re: Robowranglers 2014: Vader
 

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?

Re: Robowranglers 2014: Vader
 

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! :P

Re: Robowranglers 2014: Vader
 

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

Re: Robowranglers 2014: Vader
 

"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.)

Re: Robowranglers 2014: Vader
 

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.

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.

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.

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".

Re: Robowranglers 2014: Vader
 

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.

Re: Robowranglers 2014: Vader
 

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.

Re: Robowranglers 2014: Vader
 

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