There are other sandblasting cabinet projects on Instructables, but none use 3D printed parts, and are more expensive. (i.e. https://www.instructables.com/id/DIY-Sand-Blaster... , https://www.instructables.com/id/DIY-Sand-Blaster... ). The 3D parts make it very easy to assemble and look professional. It is essentially three large feed-throughs (M105x8mm) for the gloves/filter, and a fourth scaled down feedthrough (M35x8mm) for the air line. An inexpensive small gravity feed gun is used.
The rusted steel part (in the before and after pictures) was blasted with copper slag using up about 1/2 the tank on the gun.
Step 1: Parts
- Gravity feed sandblaster $30 (https://www.princessauto.com/en/detail/comfort-gri... )
- Heavy Duty long cleaning gloves $3.50 ( http://www.canadiantire.ca/en/search-results.html?... )
- Used bicycle tube. (or new $5.00)
- Eight 6" Tie Wraps (or wire, hose clamps)
- Coffee filter ($0.01), or small vacuum bag.
- Clear plastic container / lid $15 ( https://www.walmart.ca/en/ip/sterilite-62-liter-st... )
- Abrasive media ( I used Copper Slag $13 for 55 lbs: https://www.princessauto.com/en/detail/ebonygrit-... )
- Access to a 3D printer (priceless)
Step 2: Print the 3D Parts
Print three copies of the sb_fitting.stl (feed-through) - two for the gloves and one for the air feed-through. Print three copies of sb_nut.stl - the nuts for the feed-throughs. Printed using PLA with no supports, 0.3mm. The nuts are ~2mm larger in diameter then the "bolt" threads to make them easier to thread on - at 1 thread in 8mm a thread is ~5mm deep. Since the bolt, nut, and cutting template are all printed, variance in 3D printers is allowed for. Print one of sb_cut_template.stl - this is the template for cutting the correct size holes, as well as is used for holding a screen on the filter mount. The template for the air hose hole is sb_air_template.stl. The holes are slightly small so the feed-through will be "threaded" into the openings.
Step 3: Cut the Container Holes, Mount the Fittings and Gloves
Place the larger printed template on the container where the gloves are to go - due to the gravity gun feeding at the front of the gun (see picture of dis-assembled gun) , it has to be kept almost pointing downward. I mounted the gloves about middle of the container height, after a bit of use found this is unwieldy and uncomfortable. It is likely better to have the holes at different heights. The gun glove should be high, while the part holding glove should be lower - the gun has to be shaken and tilted down while blasting. Simulate using the gun and holding the part, to get a feel for where you want the holes, and which hand is dominate. I used a Dremel plastic cutting bit in a regular drill - cutting in a clockwise motion makes it much smoother to use. A search on the internet will show many different methods of cutting plastic (sharp utility knife, hole saw, jigsaw), but the Dremel plastic bit proved relatively much easier. Use the smaller cutting template for the air line feed-through - it seems to work well centered on the end and low in the container.
Mount the glove feed-throughs in their holes with the threads on the inside of the container - a lanolin based spray - (Fluid Film or AD3000) - helps PLA slide on itself. Silicone sealant could be used to ensure sealing to the container. Stretch the glove cuffs onto the threads and connect three 6" Tywraps ttogether, then place between the threads to fasten the gloves.
Step 4: Mount the Filter Housing and Air Line Feedthrough
With the air line feed-through mounted on the gun side, cut a section of used bicycle tube and slide one end over the threads of the feed-through. Fasten with one 6" Tywrap. A cooking grease splatter shield was purchased at a Dollar Store (or window screen or other fine mesh grid). Using the cutout template for the glove holes, mark the outside of the template on the screen and cut the screen out. Hot melt glue the screen to the template, and while still hot, stick to the inside of the filter feed-through. On the outside threads of the filter feed-through, mount a small vacuum filter bag, or coffee filter, or any other fine filter - hold filter on with elastic band or Tie Wraps.
Step 5: Suggestions / Modifications
After using the container for a while, I swapped the left glove and the filter - this put the glove off the end of the container in line with the gun (see picture above) - I found this more comfortable to use. Filter likely should exit the rear, but doesn't seem to be an issue.
While sand blasting, very little appears to go into the side mounted coffee filter - yet it seems to slightly escape through the lid flange.There are gasket lid clear containers available (i.e. picture above from Walmart), but likely have to be ordered.
Filling the gun is a little messy - I designed a funnel to fit snugly into the gun's fill port: it was difficult to hold the gun, a funnel, and pour at the same time. Printer file is attached: sb_funnel.stl . The printed sheet that ships with the gun states the gun reservoir holds ts to load 9oz - so I printed a 9oz (to the brim) cup: sb_9oz_cup.stl
A second air line feed-through could be printed and assembled with the threads pointing outwards - a vacuum cleaner could be connected to this to eliminate any dust. This may just leave the bigger abrasive media in the box to be reused?