20-02-2011 18:40

MrForbes

Re: pic: 2791 Starting Configuration

That's a really neat idea!

20-02-2011 19:54

Chris is me

Re: pic: 2791 Starting Configuration

No idea where that came from, nope...

We stepped up the PVC tube diameter for a bit more rigidity than your system. It's paid off pretty well! Now that I think about it, our robots are dramatically similar this year...

20-02-2011 20:26

Andrew Schreiber

Re: pic: 2791 Starting Configuration

How do you hold an ubertube for auton?

20-02-2011 20:30

MrForbes

Re: pic: 2791 Starting Configuration

I expect they'll have to pick it up off the floor. Probably requires a bit of forward/backward driving to get it.

20-02-2011 20:36

thefro526

Re: pic: 2791 Starting Configuration

Did you guys have something really cool in your base or was that guy just admiring your work?

Anyway, the bot looks awesome - get those guys some practice and it'll do great.

20-02-2011 20:37

Chris is me

Re: pic: 2791 Starting Configuration

Unfortunately, the gripper open breaks starting configuration, so our plan is to floor load. It probably will take more time to tune than we have to make it work (we have a Thursday) but oh well.


We've got a removable electronics board and cantilevered drive. They look cool!

We don't have much time for practice, but luckily we have a veteran driver waiting to get his hands on the bot.

20-02-2011 20:40

R.C.

Re: pic: 2791 Starting Configuration

Chris,

Great robot, did you guys not have weight for an aluminum arm?

-RC

20-02-2011 20:42

Chris is me

Re: pic: 2791 Starting Configuration

We're well under. PVC was cheaper, more available, and could more easily slide within each other without the need for any actuation. It's also easier to work with.

We bought very large (2.5" outer stage) PVC to ensure there'd be some rigidity in the arm.

20-02-2011 20:45

MrForbes

Re: pic: 2791 Starting Configuration

We have enough rigidity with a 2" outer arm and 1.5" inner. It wiggles, but that's not a problem. Using ABS lets us have less weight and a more robust arm, but as you noticed the only 2.5" you can find easily is gray electrical conduit.

20-02-2011 20:49

Andrew Schreiber

Re: pic: 2791 Starting Configuration

Perhaps look into a single shot piece that holds the tube to you and your arm grabs from at the start of match. 27 did something like that in 2005 and it worked pretty well. The last thing you want is to introduce MORE human error into your auton.

20-02-2011 20:55

Chris is me

Re: pic: 2791 Starting Configuration

There really isn't a good place to put something like that. The arm has a very limited range of travel so it can't bend around a corner to grab something weirdly placed.

Current plan is to put tube on ground touching bumper. Back up, extend arm, open gripper, drive into tube, close gripper, proceed with auton.

20-02-2011 20:55

MrForbes

Re: pic: 2791 Starting Configuration

might want to add "push tube forward" in there somewhere

21-02-2011 11:17

Joe Ross

Re: pic: 2791 Starting Configuration

That's what we did in 2007. I think we missed only once in about 50 matches.

21-02-2011 11:34

KleinKid

Re: pic: 2791 Starting Configuration

Team 3735 is earliy similar to this but our system is a little more sturdy i think. We used 1" aluminum inside of 1.5" aluminum and instead of gravity for extension we rigged up a 1.5" bore pneumatic piston. Being able to retract the arm during the game makes driving around and placing tubes on the rack much easier.

I'm very jealous and curious of your 7 victor controlers on your electronics board. 4 are probably for the CIM motors on your drivetrain but what are the other three used for other than controling the arm?

21-02-2011 11:45

TheOtherGuy

Re: pic: 2791 Starting Configuration

Looks like they've got 3 motors per side for the drive train, along with an arm and possibly the minibot deployment mechanism (haven't seen that yet, though). There's still another victor on there that isn't hooked up... maybe a quick spare?

Looks really awesome though, 2791! You guys just keep getting better

21-02-2011 12:31

Chris is me

Re: pic: 2791 Starting Configuration

This is good to hear... though, you guys had more than Thursday at a regional to test

We'd love to do something like that, but we wanted to keep it a little simpler and we didn't want to commit to pneumatics when we were designing it Congrats on your accomplishment! I'm sure your robot will kick our butt on the field.

As for our electronics board, we set it up before the design was finalized so it has 9 Victors. Plus one for a Spike for the compressor (we shouldn't need it at all with our single piston and 6.5 air tanks, but free ballast!). Originally we planned for 6 drive motors, 1 arm motor, and two motors for a roller claw, but we scrapped the roller claw with the success of our pneumatic. We're keeping the 8th and 9th on just as a spare.

I'm really proud of the extra mile we went to make a modular, removable electronics board this year. Every single plug is hooked up to an Anderson connector. Just one "click" and we're wired up.

21-02-2011 12:35

Sh1ine

Re: pic: 2791 Starting Configuration

Aluminum will definitely be more sturdy. We chose PVC so that if our arm would become tangled with another bot or element during the match the pipe would bend instead of break. And Theotherguy is right, we have a 6 motor drive train, the seventh is for the arm. We have two spares just in case we need them.

21-02-2011 15:18

robodude03

Re: pic: 2791 Starting Configuration

Ha ha ha, you weren't lying Chris when you mentioned that our bots look similar! Great job on the robot Chris and looking forward to seeing it in action. Oh btw, we changed the way our bot looks

22-02-2011 09:26

Chris is me

Re: pic: 2791 Starting Configuration

Video posted here:

http://www.chiefdelphi.com/forums/sh...69#post1029069

23-02-2011 00:47

biojae

Re: pic: 2791 Starting Configuration

It looks like your radio is plugged into the camera power supply.
Make sure that gets fixed before competitions.

08-03-2011 19:41

Akash Rastogi

Re: pic: 2791 Starting Configuration

How did I not see this thread before?

Thursday at WPI will be interesting with this bot Chris. Making any changes? btw awesome song choice.

08-03-2011 21:09

Chris is me

Re: pic: 2791 Starting Configuration

We would not be Shaker Robotics if we didn't withhold 30.0 pounds of stuff.

Luckily, we are not rebuilding this entire robot this time. We withheld our claw and reinforced major parts of it to ensure that it stays in full working order.

We will hopefully have a minibot deployment system perfected which should allow us to deploy "instantly" onto the pole like 148 does. (If not, we have a backup plan)

We will be bringing a minibot "Plan A" and "Plan B" to the event. The first is a 3 second, 100% student designed and built machine that is not the fastest but is extremely reliable. The second is a 1.4 second wonder that might just explode.

Our electronics board is completely modular (inspired by 571) and was removed for making a dummy autonomous mode. We will have to take quite a long time to calibrate it as we have far less sensors than we need, but we will make it score in autonomous, somehow.

We also have plans to redo the belting in the drivetrain for a more stable, redundant system rather than the single belt loop we have running, but that depends on whether or not we can get a replacement hex broach in time.

09-03-2011 07:13

Vikesrock

Re: pic: 2791 Starting Configuration

Just wanted to make sure this didn't get missed. Your radio power must be rewired so that it uses the 12V-5V converter with the 5V side connecting to the DLink and the 12V side connecting to the dedicated 12V power on the end of the PD (the one currently empty in the picture).

09-03-2011 08:14

thefro526

Re: pic: 2791 Starting Configuration

None of mine exploded.... Yet?

09-03-2011 08:57

Chris is me

Re: pic: 2791 Starting Configuration

We should probably write that down...

13-03-2011 01:49

Chris is me

Re: pic: 2791 Starting Configuration

One positive this weekend: We weighed this robot, with a claw made of round 1/8" wall aluminium instead of the wood used here, along with a few other weight increasing parts.

The robot weighed only 100 pounds. 20 pounds under, and everything on this bot is 1/8" wall.

Minimalism is beautiful.

One thing that turned out to be no problem was arm retraction. We took a full speed hit to the end of the arm without a scratch. The PVC's give was perfect for this. All we had to do was drive with the arm up in the air to score, and with our freakishly low CG it was very easy to do.

We had a lot of bad luck at WPI, but at least some of the cool stuff worked the way we wanted it to.