More Laser Progress

The laser is fully operational.  Some additional modifications and additions will be made before the skins are installed.  When the DB-9 connector breakout boards were rewired, during the desoldering of the stranded wire that was used initially, some of the pads got lifted and I couldn’t make a connection to the trace.  I ended up having to solder some of the wires directly to the pins.  I got new DB-9 breakouts with screw terminals instead and installed the male one.  Some communication error between me and Michael regarding ordering females over the internet caused a delay in the acquisition of the female one but it has now arrived.  I will install that in the next couple of days.

Mach 3 is controlling it but I have only cut things using a little workaround for using g-code that was generated for a router via cambam or makercam.  This involves setting the z axis control output to the laser trigger pin.  If you make your toolpaths with the minimum but nonzero cut depth, safety height, and step down increment, there is very little delay between turning on the laser and moving.

There is still an issue with the nozzle for the air that needs to be worked out.  The threads for the set screw may need to be redone.  It is hard to get the nozzle aligned properly and the set screw to hold it in place firmly.  If the nozzle isn’t aligned it interferes in the path of the beam and causes the focused beam to be smeared out or blocked entirely.

Additionally, a switch for the PWM control option needs to be put on the front panel and the power wiring needs to be finished for the back panel so everything runs off of just one plug.  At the moment, the high voltage power supply and the supply for the interface board and water pump are running off the din rail.  So any time the laser and interface board are powered on, the water is running.  The air compressor needs to be plugged in separately to the power bar that is running the computer.  Do not fire the laser without air running or you could damage the lens.  The radiator fans for the water aren’t currently plugged in, but I’m going to take some temperature measurements of the water while it is running to determine if that will even be necessary.

The potentiometer control for the power currently allows you to put more than 20 mA through the laser while running it.  It is rated for 18 mA continuous current and while putting more through it wont blow it up or anything, it will reduce the lifetime of the tube.  I am going to install some additional series resistance to the potentiometer control circuit to limit the maximum allowed current to 20 mA.

Here’s one of the first good cuts, it’s kind of hard to get good pictures of clear acrylic though.


laserlogo3small laserlogosmall


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