Full details are available on this project page : https://www.pcbway.com/project/shareproject/A_water_based_tide_clock_b2e9104c.html

This page is only devoted to the 3d printed part itself;

Choosing the printer technology

Using FDM printer would have given very poor results... So two options were open to me:

• resin 
• SLS

resin printing would have given the best details, but the model needs quite a lot of supports

This is the reason why I prefered SLS powder printing

Selective Laser Sintering (SLS) 

SLS 3D printing is an industrial additive manufacturing process that uses a high-powered laser to fuse polymer powder into strong, functional solid parts.

How SLS Printing Works

• Preheating: The printer heats a bed of fine polymer powder (usually nylon) to a temperature just below its melting point.
• Sintering: A high-powered laser traces a digital CAD model's cross-section, selectively fusing the powder particles together.
• Layering: The build platform lowers, a roller spreads a fresh layer of powder, and the laser repeats the process.

Here are the main advantages of SLS 3D printing:

No Support Structures Required

• Because the part is constantly surrounded and supported by unsintered powder during printing, SLS requires zero support structures.
• Allows complete geometric freedom (overhangs, deep channels, hollow interiors).
• Enables printing fully assembled interlocking parts and moving mechanisms in a single build.
• Saves time during post-processing by eliminating manual support removal.

High Production Throughput & Part Packing

• Without the need for support structures, parts can be nested closely together in 3D space throughout the entire build volume (known as 3D nesting). You can print dozens or hundreds of parts in a single build cycle, making SLS highly scalable for small to medium production runs.

Superior Mechanical Properties & Isotropy

• SLS parts offer high tensile strength, impact resistance, and durability. Because the laser melts layers together homogeneously, parts exhibit nearly isotropic mechanical behavior—meaning their strength is almost identical across the X, Y, and Z axes, unlike FDM printing, which suffers from weak layer bonding along the Z-axis.

Industrial-Grade Engineering Materials

• SLS primarily uses high-performance thermoplastics, most notably Polyamide (Nylon 11 and Nylon 12). These polymers offer excellent chemical resistance, heat tolerance, and structural integrity suitable for end-use functional prototypes and production components.

High Accuracy and Detail Precision

• SLS lasers achieve sharp edge definition and fine feature resolution. This allows for tight tolerances, making it well-suited for complex mechanical assemblies and precise enclosures.

PCBWay SLS service

PCBWay is well-known for high-quality PCB manufacturing. However, they also offer a wide range of prototyping services, such as CNC machining and 3D printing.

For my tide clock, I was able to test their impressive SLS manufacturing service.

Ordering is very simple, you just have to select the right options (3d printing / Nylon / SLS) and upload the .3mf file. Then the order goes into the Request For Quotation process and you will enter into contact with your Sales Representative to evaluate technical feasibility. 

All this lasts less than one day, which is great !

When order is placed, wait a few days and you will get your part!

Result is impressive !

Sealing and painting the model

Water will be put inside the hollow base. So the model must be totally water proof and sealed.

I did paint the inside with liquid epoxy resin to seal it.

Just wait one day for the resin to cure and you are now sure that potential porosity of the SLS powder has disappeared !

Once this is cure you can paint the model using acrylic paint. Then you will have to fix the paint with a matte varnish.

I only painted the houses and the ladder. The "rock" was kept without paint, the grey nylon looks good as it is !

Allow it to dry for more than a day, then apply a two-component (2K) clear coat. This step is important for sealing the paint and adding a waterproof layer.

I used the "SprayMax 2K" matte aerosol clear coat. It is a bit pricey, but well worth the cost! Apply it in very thin coats, paying special attention to the ladder, as it will remain submerged.

Next, 3D-print the base using PETG filament.

Insert the pump hoses into the designated openings; do the same for the LED. You can secure the hoses using B7000 glue, and the LED using clear epoxy resin.

Viewed from underneath, two hoses are concealed within the rock, while two others are positioned on its rear side.

The LED is hidden inside a small "cavern" created within the rock.

And here is the result before sanding the base and gluing everything together