40W CO2 Laser Engraving and Cutting Machine

So my old DIY laser cutter was a great experiment, but unfortunately the laser just wasn’t powerful enough, so I brought a new one.

It’s a “40watt” laser, and it’s pretty much the cheapest of the cheap. There are numerous problems and safety concerns with the product, but providing you’re not silly then nothing should go wrong.

After unboxing my cutter, I was disappointed in the build quality. But then, what was I expecting for a product that cost almost as much to ship as it actually cost…. and for less than £400 (all in) it’s a bargain. It took a while to get working, mainly due to the fact that it didn’t home correctly, which meant some investigation work with my multimeter. After finding the offending broken wire and bodging a repair, it was working OK.

40w laser cutter

40w laser cutter

The software was pretty easy to use, and I was up engraving and cutting within an hour or so of aligning the mirrors (yes you need to do this yourself). It’s a little bit Quirky, but for the money you can’t complain.

Some future mods will include,

  • Air assist,
  • Water temp and flow rate sensors,
  • New extraction system,
  • Increasing the cutting area.

Laser cutter update

So here’s a little update on my laser cutter,

I’ve moved over to a pre-written firmware, as writing the code for Arduino to receive and interpret the g-code was getting boring and why re-invent the wheel?

After a few mins of tweaking and some time using Inkscape to make the G-code, this is what I’ve  progressed to….

A primitive cut on my laser cutter - still needs some work.

A primitive cut on my laser cutter – still needs some work.

Still need to work on the focus and the speed settings.

16th stepping stepper motor with A4988 driver carrier from Pololu

So in an effort to control the stepper motors more accurately I’ve invested in some Pololu Stepper motor driver carrier boards. This gives 2 advantages over a traditional H bridge arrangement,

  • Micro stepping,
  • Current limiting.

Using the diagram from here but with a few changes, I pulled ms1,2,3 to high to enable a resolution of 16 microsteps, and wired it to an Arduino for control.

#define stepPin 2
#define dirPin 3
#define enablePin 4
void setup()
{
pinMode(enablePin, OUTPUT);
digitalWrite(enablePin, HIGH);
pinMode(stepPin, OUTPUT);
pinMode(dirPin, OUTPUT);
digitalWrite(enablePin, LOW);
delayMicroseconds(10);
digitalWrite(dirPin, HIGH);
}
void loop()
{
digitalWrite(stepPin, LOW);
delayMicroseconds(2);
digitalWrite(stepPin, HIGH);
delayMicroseconds(80);
}

this simple code allowed me to achieve around 3.8 revolutions per second, or ~230rpm. Which is a lot more than in full stepping mode without jumping.

CNC router no more. I’ve decided….

… to make a laser cutter instead.

I’ve always wanted a laser cutter, but I’ve never really been able to afford one.

So i’m putting the CNC router on hold for the time being and building a laser cutter. It’ll have around a 1W laser and have a cutting bed of 600 by 800mm… which is quite big for a starter project.   I want to build it spending less than £300 on parts…. so cheaper than the CNC router too.

How hard can it be? Here’s a quick Google sketch up of my idea’s

my laser cutter

my laser cutter

 

 

Arduino based DMX DeMUX – Analogue – part 2

I realised I’ve left this project hanging a while now and that’s partly to do with he fact that the chips I was hoping to use didn’t arrive quickly then other things got in the way.

I’ve also hit upon two other snaggs,

  • The power supplied from the dimmers is not 10v, so this means adding in two power regulator circuits (one for 5v data and the other a 10v reference),
  • The chips will only do 0-5v, which obviously is no good for the 0-10v that’s required.

Never mind – this is still a project i’m working on – just a little more complex than I first thought.