Let's Make Robots!

Walter 3.0

Well, here we go... Please watch the video, it explains a lot.

 ******Already an Update.... sigh******

I forgot to add some baby pictures...

http://letsmakerobots.com/node/4228 --This is with the square head and open frame

http://letsmakerobots.com/node/2818 --Even earlier.. Check the node # --I can't belive the first motor tests had the drill motors just rubbing against the wheels!!




Top of Top Deck:

Main Pics, Lcd's, Input buttons and IR in.


Underside of Top Deck:



Top Of Middle Deck:

Picaxe 18x1, Speaker Mounts and iPod mount


Underside of Middle Deck:

RF RX, Amp for Speakers and Main Power Switches


Top of Main Deck:

7.2v Packs, Sonar, Picaxe 28x2, 7.2V Pack Chargers, Fuses.

(The rectangular hole is for the main SLA 12v 12aH battery --Still gotta weld the mount)


Underside of Main Deck:

Main Motor Driver, 5V Regulators for servos and data, Neck rotate servo, servo drivers

Line follow PCB and drop-down assembly, IR Beacon finder






And here we go!














 With line follow sensor down...



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What a monster! I hope your object avoidance code is good, because you wouldn't want that running into you!

Happy Birthday too! 33 sounds scary, lucky for me I have a few years to go.

BTW: Nice neck mechanism!


For keeping straight - I like compass sensors as an easy fix (especially at that scale). All the compass sensors I've seen on SparkFun seem a little pricey to me, but they are probably better quality than the one I've used. There are a couple of complications of course, The sensor works best if approximately level, and needs to be held away from any ferrous or magnetized parts (chassis, motors, etc.).  If you can manage that then all you need is to get a bearing once you pick a direction to go, and check intermittently if your heading has changed!


6 minutes and 25 seconds of smilin from Denmark :D

I like the view of this VERY MUCH, although, I am eagerly awaiting a blog post with the code that drives the motors on the HUGE wheels...

 This is because I see you use encoders and I'm wondering how you can let a picaxe chip make sure that two wheels are rotating at exactly the same speed (using the input of the encoders)... I need this for a project for school :)

To be honest, I don't use the encoders to sync the wheel speeds. Picaxe chips are not real good at doing 2 things at once i.e. reading both wheels at once. I adjust the "go straight" stuff by manually adjusting the PWM on each motor to get him to go in a straight line. I use the encoders (or really just one encoder on one wheel) for any time I need a measure of distance or how far I have turned. If you want to sync motor speeds, you will need to check each one (one at a time) then compare the numbers and adjust from there. This can be done on-the-fly but you would need enough space for the bot to run a while while the chip takes reading off of each wheel, compares and adjusts. As always, break it down to small steps... Get the encoders to work, then figure out how to count number of marks during a given time and then you have your wheel speed. Do this again for the other wheel and then compare.
hmmm... I kinda need simultanious checking and correcting of motor speed... I think I'll need another method...

Mén, it is absolutelty amazing!! I love the details and the custom parts you have builted! BTW what material are you using?

Keep it up Chris  ;)

Ok so here is the thing.

Chris, I am sorry.

For some reason I was not going to listen to your suggestion. Who listens to chicken farmers on robotics anyway.

I have just completed reading all your posts including Walter three point oh my god.

You will be pleased to know that I have scraped the old code and have started from scratch.

Not because I cant do it but because I have a friend that really knows what he is doing.

Thank you Chris

Now be prepared for questions, Lots of them ;-)

Believe me when i say I am now a follower and a student of yours

AND I bet you will be featuring in the "BIGGER PICTURE"

Sorry again for the wise cracks. I should have gotten to know you before shooting crap at you.

Only one other man I know who produces nothing less than the best and he is the man that made me

You are too kind.

And yes, I would be happy to help you any way I can. I am glad you went through my posts. I went through some myself and was a bit surprised at just how many individual steps I have had to go through... I was also amazed that I am user #24! Man, I have been here a while. At any rate, you can see now why I am so adamant about the "break it down in steps" thing. 

Keep doing your thing and keep an eye on things here... Like I said in the video, I will post all the "sub systems" by themselves with code and good explainations.

For the first time ever, I have put someone elses robot up as a desktop image on my computer :D

Yes, I am having a real problem (post paint) with the whole gender thing... 6 out of the 7 vehicles I have owned were all girls, my computer is a girl, I dunno... I might have been wrong with the "he" thing...


Walter is shot with rust-oleum wet-sandable grey primer

Gloss Almond and Rust-oleum "Painter's touch 2x coverage" kona brown

Deck material:

The decks, servo arms, batt mounts, head --basically everything but the frame is made from Azek. Azek is a CPVC plastic sheet-good which I as a carpenter usally use for exterior trim on houses. It works just like MDF in terms of workability and how it takes paint. It is really kick-ass stuff. Google Azek


I am using 2 12v DeWalt drill motors with the transmission and clutch still attached. After removing the chucks, it left a standard 1/2-13 thread which allowed the addition of sprockets very easy. The large sprockets are from kids bikes from the dump and use standard bike chain. Both motor mounts slide slightily for chain tension adjustment.