I've just finished the construction of the acro frame and now am looking at which laser I'm going to need. This is being built to cut Nylon materials such as Cordura. I'm seeing people cutting much thicker materials and was wondering what the simplest, most cost-effective laser people would recommend for my build.
Take a look at some of the samples here for 6W laser test. Documentation (The 2nd and 3rd articles... first one is for the 2.8W.) This will give you a good idea of what you're looking at with a laser diode to cut material. While cutting with diodes is possible, it typically takes many passes, and really only handles fairly thin materials. CO2 lasers are much better suited for cutting, but that's not something you can just slap on an ACRO frame like you can a diode. It may also be neccesary to add a z axis, to move the laser focus between passes. (Or manually adjusting it.) For example, according the examples at the that link, 2mm balsa takes 3 passes, moving the Z down 1mm each pass. .5mm cardboard cut in 1 pass. 1.4mm cardboard took 3 passes. And those passes are slowed way down... 10-25mm/s. Results may vary a little between different diodes, but this will give you a good starting point to think about what it takes to cut with diode laser heads. FYI, after researching a number of different models, I did end up going with the PLH3D 6W head. But I primarily use it for engraving / etching, and it does wonderfully!
Another note is the light frequency: 445nm as used by diode lasers absorb better in organics (wood, paper, leather) and not so effective in plastics 10600um (CO2 tube lasers) absorb really well into plastics, fabrics, etc Better absorbtion = more energy imparted into the cut area = more effective
CO2 lasers are more expensive, Time is not a problem as this is very low volume that I'm putting through and really for cutting out shapes of material. These synthetic materials I've seen cutters basically melting a small spot that makes the cuts. I may use a hot knife to cut as it seals the edge. I've seen a system using a hot knife on a much much bigger table but that then involves a rotational calculation for cutting curves and also means more contacts with material causing problems. So I'm really looking for some cost effective solutions to get up and running - I have a arduino and grbl board to hand but am looking at the blackbox approach as something which is more plug and play. So perhaps, going down a route that has been tested rather than forging my own route to get this up and running. So looking at what parts I'm looking at to take a basic acro frame and get it working. Blackbox Limit Switches Power Supply Laser / Goggles WIring / Connectors Cable management / Cable Chain and clamps. Anything else I need for parts. This is my 1st project so I want to get it up and running and then I can be a bit more experimental.
Other then your frame, you'd want Blackbox Limit Switches are useful, but are not required or necessary Power Supply - You'll need a power supply to run the Blackbox and motors, and you may need a separate power supply for the laser. In my particular case, I've got a 24V PS running the Blackbox and motors, and I've go another 12V PS running my laser, LED lighting and Vent Fans for an enclosure. Wire for motors, Switches (if you decide to use them), and power and PWM for laser Cable management - You'll need something here, but could depend on frame size. The standard ACRO kits come with corrugated tubing that can work just fine in many applications. I've go the 1010 frame, and I found the runs too long and the corrugated tube too flexible to work they way I wanted, so I ended up adding cable chains to mine. Of course a laser and good eye protection are needed. You didn't mention stepper motors. I'm assuming you've already got those with the frame. If not, you'll obviously need motors as well. Couple of other things to consider or keep in mind: A lot of smoke and fumes can be generated by the laser. You'll definitely want to think about ventilation. For safety and for proper ventilation, you may want to consider an enclosure for the laser. I ended up building an enclosure and use a flexible hose that I vent out a window.
So I have a 60*40 frame and so I think I'll run into problems with cable management. I've decided a Blackbox is an easier PnP solution for getting things up and running quicker. As for fumes and smoke - I'm thinking that I had been planning on a surface with holes and a vacuum to keep the material flat and in place would be good and having an exhaust pipe with a smaller tube running near the cutter may provide some ability to suck the smoke and exhaust out the window. My belief is that a diode laser should do the trick based upon those reports. Everything is ordered and should be in a week or two.
