Let's Make Robots!

Walter Update 6.9.11

Auto, RC, Personallity, Games


Well, it's about time for another Walter Update. Busy Busy. I won't (and can't) describe the many, many hardware changes --or to the point, the transition from the old parts to the new. Instead, lets just show you Walter as he sits now and pretend he has always been this way.


I think I will let the videos and photos speak for themselves, but to give an overview... Walter is fully custom built, I made every part including many of the PCBs. He weights about 30kg and is powered by (2) DeWalt drill motors though chain drive. I recently milled some new sprockets and added another set of gearing dropping the overall ratio by another 3:1. I am not sure of the total gear ratio, but at one time you could ride on top and he is 3 times stronger (and slower) than that now. The sprockets were made by tracing another sprocket (with a Sharpie) and simply grinding them out by hand. A 12v 12Ah SLA battery takes care of the drive power via a Dagu Wild Thumper motor controller. This same unit charges the battery as well. 2 custom made (around the MAX713 chip) onboard charges take care of the 7.2v racing packs --one supplies data power, the other does the servos. Brains consist of 2 Gadget Gangster Propeller boards, one being a slave to the other. The "main" chip takes care of the "personality", navigation, video for the monitor and keeps an eye on the wheel encoders. The second "slave" chip runs all the servos, runs predetermined "head routines", fires and sweeps the sonar, tracks the IR homing beacon with the WiiCamera and also runs the WiiCamera/Laser Lidar system. The multi-cog prop system makes chip to chip communication a breeze. Each chip has a dedicated cog that does nothing but serial watching and updates variables as new data comes in. All the other cogs have access to these variables so for example, the main navigation loop never stops to go and fire off the sonar, instead the sonar is constantly being fired in the background and variables are constantly being updated. When the navigation loop needs sonar data, it already has it. It always has it. And it always has the most recent numbers. Everything is super-duper global and with the chips talking at 115,200, it is like they are one single chip. Everything is in the background, set it and forget it. BlinkM's take care of the eyes, and a MP3 player takes care of the voice. Walter uses many different voices and sound effects, the main 2 voices being A) text to speech I dub from online and B) a good buddy of my in London who records lines for me and emails them. So far, he has recorded over 200 words and phrases for Walter. I try to send him "batches" of lines to do so until I have a "batch" big enough to send, the text-to-speech voice is used. There is also a speech recognition system onboard as well but I just can't seem to find the time to do anything with it. Soon. Overall, Walter is the sum of about 2 1/2 years work, a couple/few thousand dollars (all spent in nickles and dimes) and a lot of lost hair. I would say he is about 1/2 way to where I would like him to be.

**NOTE** I have also finished Walter's new transmitter and it can be found at http://letsmakerobots.com/node/27251.


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It's a very cool looking robot.

Can you make a list where you purchased everything?

Walter IS awesome.

However, he's not a kit you can buy parts for and assemble. Check out this video (http://www.youtube.com/watch?v=Rdsc7FLwe4M) or read through the history of Walter's development in CtC's post and you will see that.

Chris is opening a web store, and will have kits available soon (not a kit for Walter, of course). Keep watch on http://rocketbrandstudios.com for more info.

Beautiful and very functional robot my friend. A piece of art with great details and lots of updates should come up in its future too :)

Walter truly is a kick-arse robot. I'm wondering if there will be arms in Walter's future?

Like, to go out and grab something?


as an American robot he has a Right to bear them?


I guess it it depends on what you see Walter doing in his future.

Will he simply drive around without hitting things? Will he be mapping his environment? Will he be mobile eyes and ears, sending you back pictures or his surroundings? --or will he be picking things up? (clothes, shoes, etc. left lying around, or samples from outside.)

It is all up to you and where you plan/desire to take him.

This is a FANTASTIC robot. (A hundred times better than my meager attempts so far.)

I love it.  Great job.


I have been keeping an eye on you as well sir. We have similar taste, I think...

I was most happy to see the two pivot-arms that make up the front suspention of your little bot. If I am not mistaken, that is a peice of 1/2" rod welded into a peice of 3/4 sq. tube (with a .120 wall thickness). The reason I recognise this is that I used an identical set-up for a bracket I made for my truck. --I had a large truck-box (tool box) that I wanted to store along the side of the bed and be able to swing this box toword the tailgate for access to its contents. I welded a bracket to the truck and beefed-up the box itself. The hinge was made from 3/4" sq tube (for the hinge nuckles) with a 1/2 rod for the pin. When done, it was the biggest, beefiest hinge I have ever welded. That 1/2" rod was just MADE to fit in there!

I also like the fact that you seem as happy with a lathe as you are with, "screw it, I can do it just fine with an angle grinder!" --This is a good place to be.

Nice to talk to you, I think I am more of a fan of you then you are of me.

Thanks for the vote of confidence.

You were right on with the sizes of rod and square tube. Happened to be some pieces I had laying around and looked like they would do what I wanted. I didn't plan the mechanical parts of the robot; just threw it together in a way that seemed like it would work.  I had to make some adjustments in the steering once it was together, but it seems all good now. (Used Ackerman steering design.)

As the original name implied, I built the body up to be a platform for trying different things. I have made a few changes in what the robot will ultimately have as I have gone along.  [Example: I got an X-band radar motion detector, but have since decided that with micro-controller leads at a premium, and not much physical space to mount it along with the other stuff, I have decided the X-band unit will not be on this one. Same with the solar cells.

I have been playing around with lasers a bit lately and trying to decide whether to mount a laser on this robot. I have pretty well decided that the laser build should probably be on its own "robot" and look more like a small anti-aircraft gun emplacement. <g>

I have a couple small 5mW lasers, a 300 mW IR; a 500 mW IR and a 2 Watt blue laser. Anything over 5 mW is dangerous to the eye, as it can blind you before you can even blink. That is why they made that 5 mW break in laser types. Below 5 mW your blink-reflex is fast enough to save your eyes. Of the larger ones, the blue laser is the safest, since the others have invisible beams, so if I make a "gun" out of one, it will likely be the blue laser. (and yes, I bought a pair of laser glasses to protect my eyes, but only one pair. The good ones are a bit expensive, but I value my eyesight.)

I have had thoughts of making a gimbol frame to hold the laser along with a visual tracking arrangement. I would like it to recognize its proper target (balloons or whatever) and then fire. I was thinking of trying to give it basic face recognition, and if it sees something that is even remotely like a face, it would abort the tracking firing sequence.

I don't want any accidents, so I would have to test that concept extensively before going with a live-fire laser. (--or use a 5 mW red "keychain" laser in testing.)

No really man, awesome bot! This is really something for a lot of people to look up to.