Bend the Bender!

Hi there, i'm new in the forum, and also in the world of arduino!

my name's Gil and i'm a 30yrs old person. native language is french but i understand english.

two years ago I built a life size "bender" from futurama, from scrap metal and an old fire extinguisher. it's a game / decoration for a aternative concert place, and it stays behind the bar. It's a purely mechanical device, and you can play armwrestling against him. if you manage to beat him (the difficulty can be set by the barman before a game starts), his chest door opens and a can of beer rolls out. plus if the barman feels like, he can press on a swith to make his eyes blink.

everything works out just fine, but now that it's been around for two years, i had plenty of time to think about it and i checked the internet to see if there was anything that could help me bring some life in that machine.

I found arduino, raspberryPi (it's ok to mention that here no? :wink: ), and some other stuff, bought an arduino starter pack, started learning and playing around, called my mother to know if she still had that c++ for dummies book i had when i was 14 or so, tore down all kind of old electronic shit that was laying around, well, i kinda liked it. I 'm an electrician, so i'm familiar with electricity, though more with AC than DC, and i had some electronic lessons in school (but that's more than 10 yrs ago).

I'm used to welding (mma & tig), metal work, woodwork, decoration & of course electricity. i had some basic skills of c++ when i was a teenager, and it comes back a bit. I now work more with decoration and that kind of stuff than as an electrician (though i lay solar panels when i need money), and i also have access to a big workshop for wood, metal and silk printing.

i guess that would belong more ito some presentation topic...

let's talk about the bender!

I'll put some pictures later so maybe people can see better what i'm talking about.

i have several different projects around him.

i want him to say things sampled from the cartoon (bought the adafruit musicmaker shield, and i am currently playing around with it, understanding how it works.)

i want a led to blink on top of his antenna (did it today) and i'd like it to blink faster when the player gets closer to win. (that shouldn't be a problem though)

i want his eyes to light, blink, dimm, and react to things he says, random sequences, and sequences triggered with the position of the arm.

i want it to have a new game button, then 3 parties, then a waiting mode.

and many more.

those are not really question yet, though i'm sure they will become in the future. up to now, i played around with several stuff, wrote some sketches to test couple of things, but nothing really yet.

i usually work like this experimenting stuf and then doing real things step by step.

now i strted to make small programms to test things and when some thing works as expected i inegrate it as a function in a larger program.

today i started to gather things in a more rational organisation, an started with a blinking led on top of hi antenna. works just fine (really?). next step are gonna be the eyes.

the eyes.... i've been thinking about it for a while, because in the show bender eyes are light bulbs, and that's of course what i used for the robot. so as an eletrician, i thought of 230v relays to control them, and then i thought which kind of lights take the best the blinking... : leds!

so i thought it would be kind of stupid to use 230v relay to control leds, and that there should be an easier and more logical way. the thing is, in order to look like bender hi eyes should still be (or at least really look like) lightbulbs... i came up with several ideas:

  1. use 23ov relays (don't like it)

  2. use the plastic light blub from the led and take away the little transformer, solder some wire to the leads of the leds, control this with a transistor, and use the little transformer to supply the leds through the transistor.

  3. basically the same as 2, but instead of reusing the original transformer, i put one with more power that supplies both eyes.

there's seven white leds in the bulb, so i guess the voltage drop would be 7 x 3.5v = 24.5v, so a 24v dc power supply powerfull enough could do the job?

havent had time to check the voltage of the secondary of the mini transfo, or anything rreally on the leds, i'm just guessing yet and thinking about it.

what do you girls and guys think?

i know this would fit in the electronical threads, but also in this, and i guess in the future i might have programmation questions or else soo... as i said : I'm new :smiley:

sorry for the long post, i'd put a potato powerd arduino picture next time.



Most definitely post some pictures. Not only does it sound neat, but could help with recommendations.

@Bite_my_shiny_metal_ass, your English is excellent but there is so much of it that I can't figure out what, exactly, you want advice about.

Maybe you can describe what you want in 5 or 6 lines in your next Reply? Please don't edit your Original Post. The info it contains may be useful when you clarify what you need help with.


Maybe you could use 8x8 led matrix for each eye. Most of Bender's emotional expressions are in his eyes. You can make him appear to look up/down/left/right, wink, scowl, squint and so on.

I'd got for a pair of TFT screens for the eyes. Like 790 from the LEXX series.

Or regular 230V lightbulbs with a triac-based dimmer circuit controlled by the Arduino.

How is the "get close to winning" measured? A potentiometer in the arm? That's super-easy with an Arduino.

Pictures please!

(The 5-minute limit on new posters will expire pretty quickly when you get to 5 or 10 posts.)

okay made some pics....

the head is in my workshop at the moment, so no pictures of the whole thing...

the head:

the potentiometer

body 1

body 2

the head with the wiring for the eye & antenna

thanks for the answers!

i was looking for guidance over the eyes, as i said, i don't want it to be a lcd screen or only leds, but just lightbulbs.

today i cracked open a pair of led light bulbs and took the two little transformer away, rewired the leds so that i can screw the eyes back in position and have the wire & transformer accessible.

that's pretty much what you can see on the last picture. the output of the transformer is 82 volts, and there's nine led/eye.

so now i use a transistor on the 82v lead to the led to control it? i don't have much experience with that but that seems a lot of volts to me?

i will use a potentiometer to mesure thearm position, good guess :slight_smile: i put a picture of some device i made quickly to see if the idea woud work on the real thing... i think it does! i have to get those eyes to blink first :slight_smile:

triacs? transistor? magic faerie powder? what do you think?

and what is the 5 minute rule :smiley: ?

and what is the 5 minute rule :smiley: ?

It was introduced to stop spammers and it is successful at that. But for others it is a PITA. It goes away after you have made 100 posts.


The pictures aren't showing up for me.

Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.,148850.0.html

It will show you how to put pictures into your post.

Tom... :slight_smile: