I picked up the super common, super cheap Harbor Freight sand blasting cabinet to replace the really small one I had recently. I had already found a lot of videos on how to improve the product with some making lots of sense and some completely off the wall and costing more than the original product.
Primarily I knew I wanted to 1) Added a metering valve suction feed instead of the pipe that I always had problems with in the small one, 2) Move my small shop vac dust collector setup over to help keep it clear inside, and 3) add some type of dust separator to avoid filling up filters or bags too quickly.
After looking at the options for metering valves online, they seemed really simple. However, searches on ThingiVerse and around the net really didn’t result in any 3D printable solutions that I liked. So I fired up TinkerCAD and played with some options.
My first clunky design likely would have worked BUT I wanted it to look a bit better and have a better tapered feed to the output so I started from scratch, found a pipe and threaded cap that seemed to fit the bill and added the features I thought were needed to make a valve work.
The final design looks better and likely will work better in the long run. No telling, the plastic may get ate up from the aggregate flowing through it all the time but the cool thing is I’ll just print another one when/if that occurs.
The shop vac exhaust was the next step and just required a couple of 90 degree adapters to mount to the exhaust port and then to the dust separator. This seems to be working fine so far but obviously time will tell.
Update 2020-01-19 – Missed an old post to approve (sorry) and saw a new post about this so here is the metering valve part on Thingiverse.