Let's Make Robots!

Cool Happenings on LMR this week (2008W46)

Let it be known to the world, once more, that letsmakerobots.com is a very live community indeed!


Here is the harvest for the past couple of weeks, or so (Week 2008 dot 46).


Community development

Check out all the new additions to our user map! Too many for me to count anymore. Many “exotic locales” among them. Or am I being a bit too “Euro-centric” there? Anyway, it appears to me that many of the newcomers (wherever their pied-a-terre) keep a low profile on the site. Are you lurking, people? Don’t feel shy! Come to the forum, ask all your newbie questions, contribute you latest inventions and have a laugh in the shoutbox with the rest of the gang. We like to make fun of each other, but never of the fresh arrivals. We’ll behave, promised!

Mr Clean likes clean designs. He is also playing with the thought of applying for the “Show Your Face on LMR” Club, apparantly.


Good on you Jedd!

Karolyn is one new arrival who did not sit on the fence for long. She wrote about how she is running a robot education programme for Canadian elementary schools. She hands over robot ideas to a local engineer, who is now busy building her a Drumming Robot. She literally takes these creations on the road. Looks like YDM is making a Grand Tour through the snowy country, with groupies and everything. Whooptiedoo!


One who already is an official member of the SYFL Club is Zanthess.


She’s graduating school soon on a robot that has no cute face, or even locomotion! I doubt the kids in class will approve. Maybe if Zanthess would allow more than four spoons of sugar in her tea?

Mr_tea__16_.jpg (video down below)

Priyanka introduced many on this site to roboting in India. Which would count as an exotic place to most people here. But then again, so would Holland 8-) . Probably more so: there are more non-Dutch members on the map than there are non-Indian members. (With apologies to Herman Finkers.)

Anyways, Priyanka’s contribution soon instilled envy and greed regarding the cool robot kit she gets to work with.


Never mind all those exotic locales. Did you also notice that this nerdy, robotnic, masculin website is starting to attract more and more ehh

… uuhhhm .... careful now Rik …. you know this one …. huhuhuhh …. gchgruchhuhcchgg ….


Shows a whole other kind of centrism in me, doesn’t it? But it raises my main question:

How politically incorrect can you be in a community like ours?

Is it okay to be sexist, or only when you are, say, married to the object of your disparagement? Is this plain wrong, or just another innocent way of turning a perfectly intelligent forum thread into a very funny one? [Kari’s e-mail address removed -here- by Rik’s censor-bot].

The page with the rating system debate consumed all the stars I could muster this week.

Frits (with an s, never a z and sometimes an l) is looking for web programmers to make letsmakerobots.com an even cooler place. Inquiries at node 2930.

One of the many wishes on the list would be a more prominent house style for the website. A logo has already been officially selected by Frits.


Some members are now wishing to have that logo on LMR swag like Techie T-shirts or Arty (worn out?) baseball caps.

Remember the motto of robot building guys! Start small, build on your previous results.

Let’s begin by putting that logo on the homepage first guys!

Another challenge has been won and the prize has been awarded already.


The winner Nick was pleased as punch with his collection of electronic components. I reckon.


Technological development

Check out this Ranger/Sizer/Tracker using dual IR sensors on pivoting mounts on top of a pivoting mount. Sometimes doubling the hardware is just double the trouble. But mintvelt also added his smarts. His future robots will all look cross eyed. And maybe a few more bots on LMR after that. Keep sharing the development people!


Just getting an LED to blink does not excite an LMR inventor for a long time. CaptainTuna is looking for a way to squeeze every little photon from an Infra-red LED without frying it. This is starting to look like proper fundamental research! And therefor I like it. And I know I’ll make good use of the results. Please do report on your findings, Captain!

On the same tangent, but at the opposite end of a photon beam, OddBot explained how to make the most of the few photons that do make it to your photo transistor.


Hooking up stuff to other stuff. That may be the definitive definition of hacking here on letsmakerobots. Finding out how to hook stuff up safely (we need a separate magic-smoke-forum at this rate!) or effectively or surprisingly happens in the forum. The results make it, hopefully, to the walk through section.

Chris the Carpenter for (one great) example found out that the “pwm signal” that an RC radio receiver gives to a servo can be read by a micro controller. The uC can feed that very info verbatim to any pwm loving device on your bot. Without interpretation or translation whatsoever. To me, it’s the verbatim part that makes this brilliant. Chris wrote/filmed this walk through. (video down below)

But the surprise did not stop there. BoA suggested that the signal received by the receiver does not necessarily have to come from any ordinary RC transmitter. It could be a hacked transmitter, Maybe a little assembler in a pic hooked up to the radio could turn it into a digital serial link. Maybe sending ascii data. Maybe multiplexing multiple servo control signals (albeit with degraded resolution). Could be a cheap EasyRadio.

Who will pick up this gauntlet and investigate? And report back. Here. To us all.

The RC hack is a fine example of making something complex very simple. I am not saying that is a good thing persé. I like it because it is new and surprising. But sometimes turning something simple into something overly complex can be just as much fun. And just as educational.

Chris is also investigating all the possibilities of eeprom memory hooked up to a picaxe. If only all those pages were properly tagged….

Imagine what his Big One would be capable of when a programmer would write a Chris-speak interpreter, reading instructions from pre-recorded eeprom! (I am only partly in jest here. But that would be my usual M.O. I suppose.)

We need more oscilloscopes in our community.


And in my lab. We learned that much in hard drive academy. A cheap, build yourself, support each other, kind of project would be awesome. Who is with me? Let’s build a few PC-scopes together!

OddBot described very clearly how he made and put to use, a sensitive compression sensor. This gives his robot the ability to “feel” how much force its pincer is applying onto an object.


The use of antistatic/dissipating foam added some serious bonus hack value. The use of cheap and ubiquitous material makes it also very repeatable.

Sometimes the greatest nonsense in the shoutbox produces some of the most briljant ideas. Hint: it is very possible to just copy and paste the content of the box into a proper page.

TheCowGod reported in his blog how he got started in a new robot related hobby: machining. He understands the power of pictures! The blog thread remained restless with oohs and aahs for quite some time. I was a bit thrown by Dan’s revelation that he spent four times more on the tooling than on the actual mill.


What are the transatlantic shipping fees from Tennessee like nowadays?

Final thought: this plus this equals what?


Groeten van



The previous "Cool Happenings" were dated 2008W43.


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That is the last time I use ms word as a rtf editor for LMR. Excusez le mess with the whitespace and stuff!

vim to the rescue!


:D Brilliant stuff, fun reading!!

Good point about the taggin! Note to myself as well!

Another great post, thanks :) BTW, I went back and looked at my machining post to see what you meant about this tooling issue. The tooling wasn't quite as expensive as that :) When I said, "The mill was about $600 including freight, and the tooling was another $2-300.", I meant the tooling was another $200 to $300. I guess that was a pretty unclear way of writing that, sorry :)


 That sure clears it up A LOT. That's like a 86% discount! OK, I am back interested again...

Wikipedia Affiliate Button

This blog Rocks!! And it is also fun to read :) Keep it up!

Too many links to outside-stuff like wiki this time though (IMHO).. I love this blog, so I want to click on everything, but it is a nag when it is "a link for the sake of it". 

(Your biggest fan, this is Stan) 

Thanks for the feedback. Nothing but thank yous and compliments nevet made one a better writer. Or a better anything.


Pleased as punch indeed ^^ 

5 *****'s!


lol, great rik :P