Let's Make Robots!

The Valkyrie

Hi all!

So the Beast is dead, buried, gone .... I actually intended to keep it as it was but hey I needed the parts :)

The new machine (Valkyrie) is basically completed and since the keyword for this one is ADJUSTABLE I still have to adjust things :D

Will start soon a new robot page for it ... stay tuned.. 

For now it draws the shapes provided, eventually it should cut them too - actually does do cutting now :D
Using a
Hi all,  As OddBot suggested on my blog I have created a robot page for this thing. I will update this page with more pictures schematics, code and video as soon … Read more

PWM with l293/l298

I hit a wall when I was trying to use PWM on the enable pins of both l293 and l298. Whatever  PWM frequency I choose it seems that I loose a lot of torque on the l293/l298 outputs with the PWM at maximum (255).

Browsing around searching for implementations I have seen that most of the time PWM is used on the enable pins, but on some (very few) designs I have also seen PWM on the input pins. 

The question is:  which is best/recommended?  PWM on the enable pins or on the input pins?

Idea: Instant messaging for LMR members?

Hi all,

Was just thinking while shouting in the Robot Shout Box, why not have an instant messaging server for the LMR members?

I have some experience with the Ejabber instant messaging server, I think it could be integrated with some work with the drupal user database.

So what do you think? 

(oh yeah and it is spelled idea ... doh)

First Cut

Here is a quick preview:

first cutFirst cut yey :D
















And a closeup:


The Beast II - Evolution

Hi all,

 In case anyone wondered what happened with that dude with his wooden CNC machine, well I'm still kicking :)

I have finally reached a milestone with this guy, software seems fine, motors turn, everything is mounted back in it's place.

I have modified the Y axis to acomodate the Z axis, reprogrammed the motor controllers many times over and over, added radiators, killed and revived the arduino software .... etc, etc, ....

 And finally it came to this:


Project: The Beast (DIY CNC machine project)

Hi all,

Meet the Beast!

The Beast















 (eh please ignore the junk around it)


l298 used for bipolar stepper control


For the project I'm working on I have designed a motor control board based on the l298 and an Attiny2313, which can be controlled using i2c.

It works pretty good but I'm having a strange issue running a 12 volts stepper: 

When I'm making one single step at a time the torque of the motor is very low no matter  how long I keep the coils energized. If I do multiple steps the torque is as it should be for this motor. 

Hello LMR

Hi all,

 I have finally decided to join LMR after about 6 months of watching and learning from you guys. 

 First of all I'd like to say Hi Fritsl, you've done a great job bringing all those people toghether by creating such a community. I wish I had this idea before you:D

I would also like  to say Hello to Chris the Carpenter, OddBot, Rik,BOA, TheCowGod you guys rock.

And least but not last Hello to the rest of people of LMR.


Ok enough hellos, back to work.