Laser Mounted, Connected, and Ready to Fire

Since I am mounting the laser on my 3D Printer the first thing that I would need is a mount.  I had already envisioned what I wanted from a mount so had it designed before I even got the laser (it was very helpful that JTechPhotonics had a model of the laser available for download).  So here is what I did available on Thingiverse.

My goal with this design was to have the laser be easily attached and detached from the printer, while being secure and stable, and allowing for a maximum of the build platform to be available. The mount slides under three of the four screws on the top of the extruder assembly for ease of attaching and detaching. I added connectors a foot or so above the mount so that the main part of the cabling for the laser and fan can stay attached to the printer between uses. I can change between printer and laser cutter in about a minute.

Here is the laser and fan mounted on the mount that I described above.  This version is printed in PLA.

Here is another copy of the mount printed using ColorFabb NGEN which has a higher melting point than does PLA.  Have it ready in case the PLA distorts.

This is a shot of the wiring for the laser.  I have connectors for the laser and fan so that I can remove the assembly easily.  The run back to the laser driver stays in place.

Here is the JTechPhonics High Power Laser Driver.  It is a nice piece of kit though my installation is not doing it any favors as I still have some wiring cleanup to do.

I am using the PWM controlled fan from my Ultimaker to drive the laser.  This posed a little bit of a challenge because there are two fans driven in parallel and if one is out of the circuit then you have no fans.  The driver effectively takes a fan out of the circuit so I needed to put a DPDT switch in place to swap between printer and laser.    The over challenge was that the Ultimaker 2 drives fans at 24V and the driver wants 5v.  A little voltage divider and that problem was solved and the voltage the driver sees is now about 6v maximum.

One last problem that will likely cause me to move to the LED PWM...when the fan is activated there is a spike of voltage!  Not sure why but it is enough to be noticeable when the laser fires and in the start of the burn.

In the next post I am going to talk about calibration and my first cut.