Diode laser enclosure

This is a "Maxaprin" laser enclosure that I bought used.

 It can be seen on Amazon under the name "Mxaprin".

 https://us.amazon.com/Engraving-Foldable-Protective-Smoke-Proof-Protection/dp/B0D2NTDJ7S

It's pretty neat in that it's foldable and portable.  But, it's also no longer being sold.

The enclosure is formed by two side panels, a front panel, a back panel, and a top cover.

When I bought it, I wasn't sure if I was going to use it as is, or just salvage the orange panels.

All of it is held together with Velcro.

The left side has intake vent holes, and a place for cords to go in.

The right side has mount points for an 80mm fan.  There are four grommets to reinforce the holes where you would attach the fan and a duct mount.

The front and top panels have orange acrylic of some sort for laser blockage.  However, not having any specs available for the optical density or wavelength filtration, they're not trustable.  I still wear safety glasses during operation.

The top is "hinged" with fabric, and has a few snap-on straps that let you open it so that it stays open.

Ventilation

The enclosure didn't have its original ventilation fan when I bought it.  Apparently, it used to have a 12v fan that ran at 7500 RPM.  It might have been a "server fan" like this:

https://us.amazon.com/ARCTIC-S8038-7K-80x80x38-Regulated-Connector/dp/B09VGT3P3N 

That one is advertised as having 118.93 CMPH air flow, though the fan speed can be regulated with PWM.  At max speed, that ends up being 4200 CFPH or 70 CFM, which is still way less than something like a 4 inch inline fan (a cheap one giving 195 CFM).

I ordered a Creality Fan Extraction Kit, instead.  That was about $25 USD, which actually cost me more than the enclosure itself.

The kit is pretty good.  Its fan is a stock 5v, 1A, 80mm fan that they say runs at 4000 RPM, and it does evacuate air well.  It has standard hole placement, which the interwebs says are placed 71.5mm apart.  It's powered from a USB power source (not supplied) through a switch.  It comes with a good, flexible hose; four typical case fan screws; a 3" duct flange; and a hose clamp.

I had hoped this would be a simple installation, but it turned out to be more complicated.  In order to add this to the enclosure, each screw would go through the flange, then the grommet, and then into the fan.  However, the screws were too short to reach.  (This isn't Creality's fault.  The original apparently came with M4x50 screws and nuts, so that would have reached all the way through.)

To compensate, I had to build a separate fan mount.  It's a simple ring with eight case fan screw holes instead of the usual four.  I cut it out of 2mm bass wood (Michael's, hobby board).  I mounted the fan at a 45 degree tilt, which actually is better for the fan's cord, anyway.  So, the case fan screws go through this fan mount, and into the fan holes.

 

Then, I modeled a "fan spacer".  This is about the same as the fan mount, but four of its holes are large enough to accommodate the head size (3.5mm)  Since the head protrudes about 3.2mm, I cut two of these to make 4mm thickness.

Though I could have, I didn't glue any of the pieces together, since they would be mounted using nuts and bolts.  

Then I used some random bolts and nuts (and I wish I had a few more washers) to mount the pieces to the wall and the flange.  

Here's what it looks like in Fusion with the fabric wall hidden.

 Side view

 

 With wall in place

 

 Physical

In my initial build of this, I didn't include the spacer, so this is what it looked like.

 Having the spacer rings in place makes it much better.  Functionally, it's probably only slightly better, but the spacer rings reduce strain on the fabric.

 I intend to have the output of this tube go into an X-Tool Fume Extractor, which has its own intake fan, and I'm not sure what that will mean in terms of CFM in vs. CFM out (where the CFM out will vary over time, anyway, depending on how dirty the filters become).  I feel like it'll cause some strange cavitation.

If the air flow isn't good enough, I might look into getting one of those server fans.  I have a 12v 80mm fan from a separate salvage, but I don't know its CFM rating.  Or, I'll see about using my existing inline fan with a duct adapter.

 Practical usage

The main practical problem with this Maxaprin enclosure is that it's tall (15.3") and deep (30").  As a result, getting material into/out of the laser is awkward.  It's inadvisable to open the right or left panels, because of cord strain.

But on the positive side, it's quite effective at shielding.

I think one thing I'll try is to add a back, bottom hinge, so the whole thing rotates.  To do that safely, I might route the cords under the enclosure.  So, maybe the whole bottom edge of the enclosure will have an L, and there will be cord holes through the lip at certain points.