HE 3D PRINTED A GOLD MINING DREDGE - THE STORE VERSION COSTS 2,000 DOLLARS
A working 2-inch dredge and 8-inch sluice box that prints in PLA and costs about 50 dollars in parts, not 2,000 dollars.
by Jingjar-Ninjar
WorkshopOpen-hardware
- difficulty
- ●●●○○
- time
- a weekend
- license
- license not specified
- repo
- repo 0 stars
●●●○○ · a weekend · license not specified · 0 stars · repo
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
Partner
COMPAREE VERDICT
This is a functional placer mining tool that prints on a standard FDM printer and runs on an off-the-shelf water pump. The maker has posted video of it pulling gravel and washing material over riffles, and the design hit the front page of r/functionalprint with over 1,250 upvotes in August 2026. The STL files are free and the print itself is straightforward PLA work. What is missing is any kind of parts list or assembly documentation — you are looking at photos and reverse-engineering the pump size, hose connections, and riffle configuration yourself. If you have done basic plumbing or pump projects before, that will not stop you. If this is your first time matching a bilge pump to a hose barb, expect an afternoon of trial orders. The second thing to check before you print a single part: whether your local waterway allows suction dredging at all, and what size threshold applies. Some jurisdictions ban dredges outright during spawning season or require permits for any motorised equipment in a stream. The files themselves are solid and the design works — the missing piece is the assumption that you already know how to source and hook up a small recirculating pump.
IN THE REPO
NOT IN THE REPO
- —STL files are provided on MakerWorld, free for personal use under the platform's Standard Digital File License.
- —No written assembly guide — the maker provides video showing the dredge running and material being processed, but no step-by-step build instructions.
- —No explicit bill of materials. You will need to identify a compatible water pump, hose diameter, and fittings by examining the photos and video.
- —The licence permits personal use only. Commercial use (e.g. running a prospecting service) is not allowed without contacting the maker.
- —Local dredging permits and creek access rules vary by region and are not covered in the project files.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Videos
Testing a 3D Printed Floating Dredge – Does It Actually Work? - YouTube
The maker posted video clips of the dredge running on the MakerWorld page, but there is no hosted build video or walkthrough. Community members on Reddit mention using the photos and brief clips as reference.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Download the STL files from the MakerWorld page and check your local dredging rules before printing anything. (The files are free for personal use. If you plan to use this commercially (e.g. offering prospecting services), contact the maker first — the MakerWorld Standard Digital File License restricts commercial use.)
- 2.Study the photos and video on the MakerWorld page to identify the pump size and hose diameter.(There is no explicit parts list. From the video, it appears to be a 12V bilge or pond pump in the 800-1200 GPH range, with roughly 1-inch hose. You will need to confirm this yourself by measuring the printed parts or testing fittings.)
- 3.Print the dredge nozzle, pump housing, sluice body, and riffles. Total print time is roughly 20-30 hours depending on your printer and settings.(Community feedback suggests no supports are needed for most parts. Use standard PLA, 0.2 mm layers, 20-30% infill. The sluice box is the largest single piece.)
- 4.Order the pump, hose, and clamps. If possible, order from a vendor with easy returns in case the hose diameter does not match.(Expect $40-$60 total for pump, hose, clamps, and any fasteners. A 12V bilge pump is a common choice because it runs off a portable battery and is already rated for continuous water use.)
- 5.Assemble the dredge and sluice, test it in a bucket or tub first, then take it to a legal prospecting site.(The maker shows the sluice resting in the creek on a simple frame. There is no detailed assembly guide, so expect to work out the fasteners and connections yourself. Test the pump flow and riffle placement in controlled conditions before you carry it to a remote creek.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The project provides STL files and video, but no parts list and no step-by-step assembly guide. If you are not comfortable reverse-engineering a pump and hose setup from reference photos, this will take longer than a weekend and may involve reordering parts.
- Dredging laws vary widely by jurisdiction and waterway. Some areas ban suction dredges outright, others allow them only outside spawning season, and some require a permit for any motorised equipment in a stream. Fines for illegal dredging can be substantial. Check your local fish and wildlife agency rules before you build.
- The pump size is not specified. From the video it appears to be a small bilge or pond pump, but matching the hose barb size to the printed nozzle is trial and error unless you measure the STL in CAD software first. Order from a vendor with easy returns.
- PLA will deform in hot sun or a closed vehicle. If you are prospecting in summer heat, consider reprinting the stressed parts (nozzle, pump housing) in PETG. The maker used PLA and it held up in the video, but that was running in cold creek water.
- The riffles need to be angled and spaced correctly to trap fine gold. The STL includes the maker's riffle design, but if you modify the sluice length or width, you will need to understand placer mining principles to re-space them. The design as provided is proven to work.
- This is personal-use only under the MakerWorld licence. If you want to build multiple units for a prospecting club or offer dredging as a service, you must contact the maker for a commercial licence.
What pump do I actually need?
The maker does not specify a model. From the video and community discussion, a 12V bilge or pond pump in the 800-1200 GPH range appears to be the right size. Look for a pump with a 1-inch or 1.25-inch outlet, measure the printed nozzle to confirm, and order from a vendor that accepts returns in case the fit is wrong.
Will this actually find gold?
A dredge is a tool, not a guarantee. It works by the same hydraulic principle as commercial dredges: water flow and riffle design concentrate heavy material, and gold is the heaviest thing in most creek gravels. Whether you find gold depends on whether there is gold in the creek you are dredging. The tool itself works — the maker posted video of material being processed — but it cannot create gold where none exists.
Can I dredge any creek?
No. Many jurisdictions restrict or ban suction dredging, especially during fish spawning season. Some require a permit for any motorised equipment in a waterway, others set a size threshold (e.g. dredges under 2 inches are exempt, but this is a 2-inch dredge so it sits right on the line). Check your local fish and wildlife agency rules before you take this to any stream. The files are legal to print; using the tool may not be legal everywhere.
How much gold can I expect to recover?
That depends entirely on the creek. A 2-inch dredge can process roughly 0.5-1 cubic yard of gravel per hour in good conditions. If the gravel contains fine gold, the riffles will trap it. If the creek has already been worked over or there was never gold there, you will recover nothing. This is prospecting equipment, not a money printer.
Can I sell the dredges I print?
Not under the MakerWorld Standard Digital File License, which restricts commercial use. If you want to sell finished dredges or run a prospecting service with this design, contact the maker (Jingjar-Ninjar) to negotiate a commercial licence. Printing one for yourself or a friend is fine.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The maker posted video of this dredge pulling gravel and washing it over riffles, but no parts list or assembly guide — just STL files and reference footage. If you have built something similar (pond filter, bilge pump setup, aquarium plumbing), what pump and hose size would you start with?
Jingjar-Ninjar
Jingjar-Ninjar published the dredge and sluice design on MakerWorld in August 2026, with video showing it running in a creek and processing gravel. The post hit the front page of r/functionalprint with over 1,250 upvotes. The maker has not provided a detailed build guide or parts list, but the STL files and video are enough for someone with basic pump and hose experience to replicate the build.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM3d ago
Practical notes from our verification: the MakerWorld page includes video clips of the dredge running in a creek and material being washed over the riffles, which is more proof-of-function than most 3D printing projects provide. The missing piece is any kind of parts list — the pump model, hose size, and fittings are not documented, so you are reverse-engineering the plumbing from photos. That is not a dealbreaker if you have done basic pump projects before, but it does mean this is not a one-weekend build unless you already have a parts bin with the right pump and hose on hand. The legal side is the bigger gotcha: dredging rules vary by waterway and season, and some jurisdictions ban suction dredges entirely or require permits. The files themselves are solid and the design works, but check your local fish and wildlife regs before you spend a weekend printing it.