pic: 1726 NURC robot prototype

Here’s FRC 1726’s pending robot design for the National Underwater Robotics Challenge (June 6-8, 2008). We’ve spent some time brainstorming and reflecting on last year’s competition, and came to several conclusions that greatly aided in the construction of this year’s robot. We’ve shifted to on-board electronics, resulting in an incredibly smaller tether and a single-bodied design (less things to waterproof). So far, the design is both cost efficient and simple, allowing a small swarm to be constructed ( :slight_smile: ).

For more pictures on the build and robot, check out our photo gallery.

For a video of the initial test drive*, see our YouTube video.

Good luck to all NURC participants this year, and thanks Fredi and the entire Carl Hayden robotics team for hosting this wonderful event! 1726 can’t wait to see everyone there!

*the robot drives pretty slow in this video, but after checking the battery voltage we realized they had close to no charge… we’ll test it soon with fully charged batteries!

Holy crap that is so cool! What does it take to be in a competition like this? I would love to see robots like that working under water! Where is it that the competition is at? Maybe I can come watch.

The competition is in the Phoenix area


and this year’s event is full (24 teams entered)

Oh wow that design looks really interesting!
I’m glad you guys finally got signed up. I can’t wait till competition day to see how your design works

Fantastic guys! Keep it up. We are building our new one this year. Here is the team website with some picts so far
We have two full sets of prop to build!!
We have a lot of work to do.
We also want you guys to be involved in the design of the next APASE competition. We will talk more later!

Thats pretty cool, I want to make one now. BTW, what is that vex part that appears in picture 13 of the photo gallery?

That would be the Vex signal splitter. It’s the non programable version of the vex controller, and it only has 6 pwm outputs and no inputs. Tiny, too!

Thank you, thats very interesting, I might have to get me one of those so I don’t have to worry about the micro controller all the time. And the size is another advantage for applications like these. :smiley:

The vex signal splitter is a neat thing, we’re using it with 3 Banebots speed controllers to drive the T500 bilge pump motors. The batteries are two Vex 7.2v 2000mAH wired in series to provide nominal 14.4v. The splitter takes power from the speed controller’s Battery Eliminator Circuit.

We looked at the signal on the tether output port on the transmitter using an oscilloscope, and it’s a nice 6 channel PWM signal, on the red and green wires in the 4 conductor connecting cable.

I wonder if we can do some more compacting work to be able to fit more stuff in the robot…it’s getting crowded in there! Wires take up a lot of room.

looking good team 1726

This is fascinating! If the little signal splitter is non programmable then what controls in the operator side controls the pwms. I can see the joy sticks with making 4 where are the other two. The buttons? They won’t be speed controllable hough, right?

What current are you drawing with 12v and max. thrust? per bilge pump?

That’s an experiment that still needs to be done! I think Gary sees the need to do the experimenting, so maybe it will get done soon…

As for the signal splitter channels, it uses the 4 joystick axes to control the first 4 outputs, and the buttons for the last two. IFI suggests not using the last two channels with servos, as they seem to have some jitter at the neutral position.

Excellent job on the photo gallery!

How stable is it underwater? What keeps it in it up-right position?

Have you named it yet?

We did a little experiment. Modified Plane props, three blade reverse pitch 4 inch versus muffin fan 4 inch.
Plane 12v 4to 5 newtons at 8amps full throttle
Muffin 12 v 7-8 newtons at 8.5amps full throttle

We are building a second bot to assist the mother bot. We have not figured out what config. we are going with the little bot. On board batteries, off board??? we want a fast very maneuverable bot to help the lumbering mother bot.

quick answer for the current draw question…5 amps at 13v (with two 7.2v nicad packs in series)

a few pounds of steel stakes keep it upright (they are tie wrapped on the bottom skids).

I don’t think they’ve come up with a real name yet, but I’m sure it will be highly technical when they do!

Do you know how much thrust they put out? We are using the Mayfair cartridge bilge pumps 1000gph

You can get them at http://www.overtons.com/modperl/product/details.cgi?i=27399&pdesc=Replacement_Cartridge_For_1000_GPH_Pump&cname=Bilge-Pumps&aID=24F&merchID=1009&r=view
In the pic it show a 750gph, they were lazy and used the same pic

Did you see the poster for this year, its going on the t-shirts! Look at the pics featured on the left.