2 inch dredge/8 inch sluice box for gold mining

Knockdown unit can be moved forward to allow for shoveling/inspection of the first section

Adjustable legs - quick-release

Works well with Utmost Outdoors nozzle and bilge upgrade

This is intended to be used with a suction nozzle system (I use the one by Utmost Outdoors) and a 4700 GPH bilge pump. It can be run as a dredge by attaching the outlet of the suction nozzle to the header, or as a powered sluice by attaching a 3700 or 4700 GPH bilge pump directly to the header.

Instructions are for dredge setup. Sealing is NOT required. If you wish to seal seams, you can use CA glue (permanent) or place Gorilla tape over seams. I have had no issues running it for 12+ hours unsealed.

These parts are designed to fit on an A1 bed (256mmx256mm). They can be scaled down 25% to create a 6” sluice for a 1.5” dredge, at which point I would switch to regular moss/matting/non-dredge dream mat.

Parts list

25 M6x20mm bolts (head <10mm width, usually hex bolts)

5 M6x30mm bolts (head </= 13mm width, 13 mm preferred)

24 M6x7.1x8.0mm brass inserts (WxD)

Other things you will need

Smooth wall hoses (very important that the inner walls are SMOOTH or you will lose suction power), 2”x 6’ (outlet from suction nozzle)/2” or 1.5” x 4-5’ (pressure hose) with clamps Shorter hoses are always better for pressure loss, so find the length that works for you

Matting: This is designed to work with 8” of miner’s moss/V matting followed by a 8x24” dredge Dream Mat. If you intend to use something else, each sluice and end unit is 8” by default, but you will have to find a way to clamp it

8” wide mat/rubber sheet for knockdown flap

4700 GPH bilge pump Optional: Bilge pump upgrade from Utmost Outdoors. I have not had good success with it, but others have

Battery for bilge pump

Printing instructions

Print header, knockdown, base, 2x sluice, expanded metal clamp, and end unit, with 4 legs

Files are provided as STLs

HIGHLY recommend printing in regular PETG (not HF), as high temperature as you can with minimal-light stringiness If stringy, blast with a heat gun

Recommend using a 0.6 or 0.8 mm nozzle – 0.4mm will take a very long time to print. I used a 0.8mm nozzle, 1.2mm thick lines, 0.45mm layer height with adaptive layer heights to help with holes

Minimum wall thickness (including top layer): 2 mm (recommend 3+ mm) It is not necessary to print at 100% infill (use 20-40%, gyroid or 3D honeycomb infill)

You can use modifiers to reduce material usage. E.g. the top 4” of each unit can be printed at 2mm wall, 30% gyroid infill)

Most parts have 1 section of supports. You can either print the supports in a different material (PLA for PETG), or, you can add a pause to the print at the support interface layer and apply Sharpie liberally across the interface

IMPORTANT NOTE ABOUT EM CLAMP: You may have to rescale in the Z direction to match the thickness of your moss/matting. The top surface of the expanded metal portion of the clamp should be just below or level with the bottom of the header.

Assembly instructions

Every blind hole gets a brass insert

Base unit: 6 extra brass inserts (4 on top, 2 on back) for attaching the knockdown and header units, respectively

Each section: 6x brass inserts, connect sections using 6x M6x20mm bolts Head width must be less than 10mm to avoid interference

You can also use 4x inserts/bolts by skipping the middle hole on each unit

Header unit: 2 M6x20mm bolts, attaches to base unit

EM clamp: M6x30mm or longer bolt with wingnut, pushed through your moss/mat/carpet. I used V matting under moss under the EM clamp.

Knockdown unit: 3x M6x20mm bolts with wingnuts (to secure knockdown flap)

Legs: Each leg is attached with a M6x30mm bolt. It is not necessary to add any sort of nut to the bolt; the weight of the sluice and tight clearance keeps it secure. I have never had one fall out, and you can adjust legs by popping them out and back in quicker

Other notes

This design is not perfect, but it does work well. There are some things I intend to improve in the future, most notably adding a highbanker box, updating the clamping mechanism, and adding ribs to the sluice units. If you have ideas or would like to contribute, feel free to leave a comment.