As if I don't have enough projects on the go, I decided to start building a 750mm X 750mm laser engraver based on Openbuilds 20X40 extrusion (I had some left from another project) Have everything test fit, just need to cut the X axis plate on the laser (I have used a 3d printed plate for test assembly that I had around). Waiting on some GT2 belt and pulleys, as soon as they arrive, I can do the final assembly and mount the controller (Grbl this time) and the laser diode (a 6.8W monster, PWM controlled). I was thinking of also making it so that I could attach a 300 or 400w air cooled spindle for PCB engraving and light cutting. It is based upon some of the 20X20 extrusion builds on the Openbuilds site, I just thought that 20X40 would be a little stronger in the long run. I have a 3d printed X axis slide that will go on it so that I can easily adjust the laser focal point depending on the thickness of the work piece. I will post some pictures of the build and the plate files and BOM later this week.
December 14. 2016
I have sort of put this project on the back burner for now, waiting for parts to arrive so I can finalize its design. I would welcome some advice however on material choices for the gantry plates. I do not think that a laser engraver needs aluminum plates, but I would like something that is more dimensionaly stable than MDF (Which is what I am prototyping this build with), but has more strength than acrylic. Does any one have any brilliant ideas?
December 18, 2016
Just a few images of the prototyping stage, using mdf for the plates until I decide on Garolite or Aluminum for the final build.
December 29, 2016
Decided to use 6mm acrylic for the plates. If I ever decide to put a small 300W spindle on it, I will upgrade them to aluminum. Still waiting for the belt and pulleys to arrive, sort of at a standstill until I get them.
February 17, 2017 Still waiting for the acrylic I ordered, So I am going to assemble it with MDF prototypes for now. Should be stable enough for a diode engraver.
March 7, 2017 All the parts have arrived, so it is time to put it all together and set up a grbl controller for it, most likely running LaserWeb.
May 11, 2017
Decided to use HPB's modified stl files from his build A simple XY laser engraver/cutter . He modified them to use the 20X40 extrusion I had. Here is a link to the STL files. https://www.openbuilds.com/attachments/motor_mounts_for_2040_extrusions-zip.20329/ Will post pictures once I have switched to thes 3D printed plates. I really like the design he came up with, but I wanted to have the machine be a little stiffer so I used the 20X40 v-slot extrusions in this build.
Back to the original MDF plates for now, I do not like the mini wheels, so I will be cutting some 1/4" acrylic plates like the MDF ones.
May 18.2017 Went to cut some 1/4" acrylic plates to replace the mdf, and it turns out the shady sell sold me some polycarbonate instead of acrylic. It is NOT laser friendly. So I cut it out of some 2mm acrylic I had on hand, layered 3 pcs together, and because of the way it is made, there are more than enough through holes that it reacts like a 1/4" pc. Will leave it this way for a while, no use fixing something that is not broke. Will cut out 1/4" acylic (which I now have) if they do not perform well. I also modded the X axis plate to allow for easier mounting of the Z axis slide.
May 22, 2017
Looks like I will be cutting some 1/4" acrylic plates after all. The 3 laminated layers do not have the stiffness I am looking for.