My weekend project!!
A vacuum air filter for my Shapeoko 2 and Laser cutter 
@Grant_Macaulay How does this work? Any Construction details available? I build a dust collector for my CNC router, but still dust gets in the air, so if this scrubs air around it I am interested in building similar.
I have been mulling over the design for weeks. Final drew them up yesterday and started laser cutting yesterday!!
I am seriously thinking of putting this all on Instructables. Maybe even a kickstarter making the plans available to all.
Just plugged it in and switched on the vacuum. It works so much better then I had expected :))
I bought an out of date car air filter from the local shop and put all the dimensions around that. Better go buy a few more. Already thinking of adding a large particle filter I front of the car filter and using it on my laser cutter project.
I also removed the dust bag and all the filters in the vacuum.
I have got to put it on the CNC to test how well it works. I need to build a suitable mount for the Makita to take this 57mm tubing.
An Instructable would be welcome.
My old design air scrubber used a cheap HVAC prefilter and a HEPA MIRV 11 Triton Air Bear brand filter assembly (five inch deep and easily replaceable) and a recovered blower assembly out of an old mobile home furnace (120V motor capable of high static operation). The exhaust can be in the room or run outside as needed. This system cannot use a shop vac effectively, but can be connected to a dust collector blower in place of the blower (high volume of air moved makes the dust control much more effective). I also much prefer a metal shell and ducting with external sound control (I think the possibility of a fire from a hot particle off a machine is way too high and the air movement is a perfect oxygen source).
I will build a new one when I relocate to my long term shop, but I can hash out a quick plan if anyone is interested.
Plans would be welcome Bear,thanks.
I have a Sketchup file of a basic layout which can be configured for horizontal or vertical installation and freestanding or hanging (my original layout was vertical and freestanding on vibration isolators to minimize noise and was later changed over to horizontal and hanging from the ceiling joists by threaded rod). The blower is recovered from a HVAC air handler or furnace and the outlet of the blower is partially covered by an adjustable plate to adjust the backpressure so the motor does not exceed the Full Load Amperage (FLA) rating and overheat. The prefilters and Air Bear are held in place by a simple āCā shaped sheet metal frame.
Let me know how to send you the Sketchup file.
I have added two more stages of filtering add mounts for my CNC and tested it in anger on my first metal cut. Really happy with the out come.