Ogre - a LEGO NXT based "tank"

[Brian Davis-3]

OK, it was pointed out to me that I hadn't actually announced this on LUGNET,
so... Ogre is the logical (or perhaps I should say "obsessive") conclusion to a
series of Zamor shooting robots I've played with for a while. The launching
system fires about 9+ spheres per second at about 4 m/s, and the ammo magazine
holds about 50 spheres (without jamming too often). I started out trying to hold
off using NXT motors (at first I wanted a pan and tilt turret, but ended up with
a fixed main battery), so I used PF motors. This has the nice side benefit of
making the tank "automatically" and RC vehicle; just don't turn the NXT on, and
the entire thing works very well under RC control from two stock PF remotes
(mated side-to-side, with one upside down; the inverted one you pull back on a
toggle to fire, while the upright one controls the two treads). The upper bogies
in the treads are sprung with shocks to keep the large tread systems under a
fairly constant tension, and as a bonus it has a little mini "spy cam" on one
side.

The NXT can control the unit fairly well - actually, better than I can with the
remote. By using the Hitechnic IRLink, the NXT control can use PWM on the PF
motors, resulting in much smoother control for turns and variable speeds. In
contrast, a human behind the controls tends to look jerky and inexperienced. It
is a lot of fun just to play around (we'll be finding Zamor spheres in the
living room for the next decade I suspect), but it's wonderful to watch it "Take
out" at target autonomously. No BS Gallery as yet, but here's a YT video:

http://www.youtube.com/watch?v=DNHGaSagaM4

Yes, LEGO doesn't make tanks. But thank goodness all the pieces are there for
the rest of us. Stormtroopers, beware!

--
Brian Davis

[Scott Lyttle]

In lugnet.robotics, Brian Davis wrote:

> OK, it was pointed out to me that I hadn't actually announced this on LUGNET,
> so... Ogre is the logical (or perhaps I should say "obsessive") conclusion to a
> series of Zamor shooting robots I've played with for a while. The launching
> system fires about 9+ spheres per second at about 4 m/s, and the ammo magazine
> holds about 50 spheres (without jamming too often). I started out trying to hold
> off using NXT motors (at first I wanted a pan and tilt turret, but ended up with
> a fixed main battery), so I used PF motors. This has the nice side benefit of
> making the tank "automatically" and RC vehicle; just don't turn the NXT on, and
> the entire thing works very well under RC control from two stock PF remotes
> (mated side-to-side, with one upside down; the inverted one you pull back on a
> toggle to fire, while the upright one controls the two treads). The upper bogies
> in the treads are sprung with shocks to keep the large tread systems under a
> fairly constant tension, and as a bonus it has a little mini "spy cam" on one
> side.
>
> The NXT can control the unit fairly well - actually, better than I can with the
> remote. By using the Hitechnic IRLink, the NXT control can use PWM on the PF
> motors, resulting in much smoother control for turns and variable speeds. In
> contrast, a human behind the controls tends to look jerky and inexperienced. It
> is a lot of fun just to play around (we'll be finding Zamor spheres in the
> living room for the next decade I suspect), but it's wonderful to watch it "Take
> out" at target autonomously. No BS Gallery as yet, but here's a YT video:
>
> http://www.youtube.com/watch?v=DNHGaSagaM4
>
> Yes, LEGO doesn't make tanks. But thank goodness all the pieces are there for
> the rest of us. Stormtroopers, beware!

Now, that's just flat out cool...and fun!!!  (except for maybe...the cats.)

I'm curious if soccer/foot balls and basketballs can work in place of Zamor
spheres.  

Scott

[Brian Davis-3]

In lugnet.robotics, Scott Lyttle wrote:

> Now, that's just flat out cool...and fun!!!
> (except for maybe...the cats.)

Thank you - and don't worry about the cats, they think LEGO robots roaming
around the house are normal. All depends on the environment that you are raised
in...

> I'm curious if soccer/foot balls and basketballs
> can work in place of Zamor spheres.

They don't. The launcher works be squeezing the sides of the spheres as they are
pushed forward between two "fingers". The soccer ball size is just a little bit
smaller (a soccer ball will fit in a 2x2 space, while a Zamor just barely
doesn't... an issue that has foiled many a GBC builder trying to use Zamors as
well).

The good news is it looks like LEGO is still producing these parts (or has a lot
in storage), as they appear in the NXT 2.0 kits.

--
Brian Davis

[TooMuchDew]

In lugnet.robotics, Brian Davis wrote:
> OK, it was pointed out to me that I hadn't actually announced this on LUGNET,
> so... Ogre is the logical (or perhaps I should say "obsessive") conclusion to a
> series of Zamor shooting robots I've played with for a while.
>snip<
No BS Gallery as yet, but here's a YT video:
> http://www.youtube.com/watch?v=DNHGaSagaM4
Brian,
This is super cool! I first saw this from the post at
http://i.gizmodo.com/5162330/lego-mindstorm-ogre-autonomously-detects-targets-and-destroys-other-lego-creations
My son and I watched the video through 3 x and his comment every time is "We've
gotta learn how to build one for ourselves!"
Now you need a companion bot that goes around and cleans up all the Zamor
spheres  :)
Please let us know when you've updated your Brickshelf gallery with pictures.
--
Bill
(TooMuchDew)

[Teddy Welsh]

Sick.  Majorly, majorly sick.

Coming to a fest near us sometime soon?

[Steve Hassenplug]

On Wed, Mar 4, 2009 at 2:45 PM, Teddy Welsh <ewelsh@...> wrote:
>
> Sick.  Majorly, majorly sick.
>
> Coming to a fest near us sometime soon?


Only if you're coming to a fest near us.   :)

[Brian Davis-3]

In lugnet.robotics, William Toenjes wrote:

> This is super cool!

Thank you - I glad folks liked this.

> I first saw this from the post at [Gizmodo]

And I'm somewhat shocked at what hitting Gizmodo does to view statistics on
YouTube. Wow. I can see why /. can set down a server *fast*...

> My son and I watched the video through 3 x and his comment
> every time is "We've gotta learn how to build one for ourselves!"

While I don't have BS photos up yet, Steve Hassenplug was kind enough to put up
a webpage on it on his site:

http://www.teamhassenplug.org/robots/OGRE/

I'll need "deconstructive" pictures at some point, but for now this is the
source for Ogre. The Hailstorm launcher I did actually draft up in LDD, and put
on NXTlog:

http://mindstorms.lego.com/nxtlog/ProjectDisplay.aspx?id=ce5fa394-669f-4f66-a260-ef5e6c2e8fb2

> Now you need a companion bot that goes around and cleans
> up all the Zamor spheres.

Yes - it's been suggested more than once (and my wife agrees) :).

--
Brian Davis

[Eric Sophie]

Mr. Davis! I just watched the video, AND IT IS AWESOME! That combination of
controls is fantastic. I am really glad you posted this creation. I couldn't get
over the way the thing shoots! It is utterly _!_ridiculoid_!_ LOL! <3

I really like the video method you used to present this creation.

Ok, again, I can't get over the volume that this thing puts out in Zamour
Spheres! LOL! Hailfire system.... oh man....

I want to learn more about this IR Link from HiTechnic.

...and YOU sir WOULD have a Black NXT, bravo.

Thanks again! Awesome MOC.

Eric Sophie

[Brian Davis-3]

In lugnet.robotics, Eric Sophie wrote:

> I just watched the video, AND IT IS AWESOME! That combination of
> controls is fantastic.

Thank you! The controls started out unintentional - I really wanted to use the
NXt motors with encoders for other functions, so started out with just the XL PF
motors. But as it is, it works great. It actually allows a third dual-control
mode as well, where the user "drives" it around, and once a target is detected
"within range" the NXT can take over control and do an automated firing
sequence.

> I really like the video method you used to present this creation.

Thanks - the videos take a little bit of time to put together, but it's kind of
like photographing MOCs... there's a fun creative aspect to the documentation
that I enjoy as well. And really, for most of my creations showing them in
motion is really the only way to begin to get a feel for them. I've actually got
a very poor stop-motion assembly sequence for this critter that I need to slap
together. I didn't have enough time to photograph enough frames properly, but it
should still be sort of fun to watch. I've got most of the still images up on
Brickshelf now, so if anybody wants to build it they can replicate it from the
(large number!) of pictures:

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=374902

> Ok, again, I can't get over the volume that this thing
> puts out in Zamour Spheres! LOL! Hailfire system.... oh
> man....

If you like losse-stacked LEGO destruction, see my other videos Hailstorm:

http://www.youtube.com/watch?v=ZB3dFFHUoPs

and "Frangible LEGO":

http://www.youtube.com/watch?v=aYPpkMiB07I

> I want to learn more about this IR Link from HiTechnic.

It's very handy. With a single IRLink, you can control all four channels of the
PF system, giving you 8 PF motors to work with. While you don't have built-in
motor encoders, the IRLink can control the PF system at 8 different power
levels, much better than you can do with the PF Remote currently (the remote
only allows three states: On Fwd, On Rev, and Stop). The slow panning turns that
Ogre does under NXT control aren't an option with the PF remote.

> ...and YOU sir WOULD have a Black NXT, bravo.

Story: This got carried by Gizmodo (boy does that drive up the YT hits), and I
dropped in at one point to see the comments. My favorite was from Purple Dave,
who was commenting about the model and then realized who had built it, and added
comments to the effect of how surprised he was... knowing me, and my "Rainbow
Warrior" building style (his words, not mine), he was very pleasantly surprised
how color-coordinated it looked. He's right, I've got a real "function over
form" mindset, but now and then, I rise above it... and the black NXT just
worked perfectly in such an "aggressive" color scheme.

--
Brian Davis