Let's Make Robots!

DIY laser cutter

Reading about all those lucky people that have access to a laser cutter, i was wondering: can we make one? I mean, build a custom (cheap) laser cutter?

I think it should be something like a plotter, so with a couple of fine-grained steppers and a frame structure (maybe some old scanner) that should be ok.

The problem is the cutting :P where can one find a good laser? i thought about CD-Writer but they have about 100 mW.. I don't know, maybe it's enought for a small dark acrylic sheet.. But i think the optical stuff won't fit :)

Encoders, what are they ?

So what is the difference between a motor with an encoder and one without?

i think it kinds of read how much the motor is rotating, but can't i see that from how much current i'm giving? what are the uses for these encoders?

The infamous Kalman Filter :)

So maybe any of you heard about it, but is there anyone who have made a working implementation?

Or eventually a nice site with a human readable explanation :) ?

Useful robots

Hello :)

I have this question: has any of you ever built a useful robot, that is, a robot with some real task that helps you, instead of just making it for fun ?

The other day a friend of mine was complaining about the time it costs him to cut the grass, and told me jokingly he could use a nice autonomous robotic lawn mower. I thougth that it could be a task within our building abilities.

What other useful robot could be realistically done?

Favicon for Let's make robot

What about changing that default Drupal favicon to something custom ? :)

Output pin voltage

Hello! I'm working on a Picaxe 28x1. I can't find in documentation what is supposed to be the voltage of the output pins.

I've used a tester to check and it's very low, about 1, 1.5 Volts. Is it normal that it's so low ? Is that enought to use with a transistor?

 Thanks :)