Step 1 - Modifying the SAMLA container

As shown in the drawing, a rectangular hole must be centered at the bottom of the container.

• Cutout Dimensions: 160mm x  133mm

• Purpose: This opening provides the exit path for water after it has passed through the ReefMat 1200 media. The dimensions are calculated to match the internal 3D-printed screen, ensuring that water cannot "bypass" the fleece.

Step 2 - The Screen 

Dual-Layer Media Guide

The ReefMat 1200 media is "sandwiched" between two 3D-printed screens to ensure perfect tracking and filtration.

• Bottom Screen: A tight diamond grid that prevents the wet fleece from sagging into the exit hole.

• Top Screen: A wider, open frame that prevents the fleece from floating while minimizing surface contact.

• The 1mm Gap: When assembled, the screens maintain a precise 1mm clearance. This gap is narrow enough to force water through the media, but wide enough to eliminate mechanical drag on the motor.

Step 3 - Rollers 

Friction-Reduction Rollers

To further minimize mechanical strain, two free-spinning guide rollers are positioned at the intake and output of the screen assembly.

• Smooth Transition: These rollers prevent the ReefMat fleece from catching or rubbing on the sharp 90-degree edges of the 3D-printed frame.

• Reduced Motor Load: By converting sliding friction into rolling motion, the 8RPM motor can pull the fleece with significantly less resistance, even when the media is heavy and saturated with waste.

• Perfect Alignment: The rollers keep the fleece centered as it transitions from the ReefMat roll, through the "sandwich" screen, and up to the waste take-up spool.

Step 4 - Hold Down Brackets 

The Hold-Down Brackets are the final piece of the "wet-side" assembly. Their primary job is to fight buoyancy. Without these, the entire screen and fleece assembly would lift as the water level rises in the bin. These brackets provide positive downward pressure to keep the unit seated.

Step 5 - Flow Distributor 

The Flow Distributor is a two-part assembly designed to take turbulent water from the drain and spread it evenly across the media. To ensure a smooth surface and maximum strength, this part utilizes a heat-forming technique.

• The Design: The distributor is printed as two flat components. This eliminates the need for 3D-printing supports and results in a smoother surface for better water flow.

• The Process: After printing, the center piece is heated with a hair dryer until pliable. It is then bent to the specific angle required to meet the main housing.

• The Result: The final "ramp" features a notched bottom edge (fingers) that breaks the surface tension of the water, distributing it evenly across the ReefMat 1200 fleece to prevent "channeling" or localized clogging.

Step 6 - Lid Cutouts 

Three specific openings must be made in the lid to accommodate the internal components:

1. The Intake Hole (Circle): This large circular cutout allows your main drain pipe or hose to enter the Flow Distributor box inside the bin.

2. The Fleece Slots (Rectangles): Two long, thin slots allow the ReefMat 1200 fleece to pass through the lid. One slot is for the "Clean" fleece entering the bin, and the other is for the "Dirty" fleece exiting toward the take-up spool.

Why modify the lid?

• Salt Creep & Humidity: Keeping the lid on (even with cutouts) significantly reduces salt creep and evaporation within the sump area.

• Structural Support: The reinforced rim of the lid provides a stable platform for the 3D-printed "Bridge" that holds the motor and the heavy ReefMat roll.

• Alignment: By using the lid as a template, you ensure that the fleece is perfectly aligned with the internal Screen Assembly and Rollers below.

Step 7 - Media Bridge Gantry 

The Media Bridge is the structural "skeleton" of the unit. It is designed to suspend the fleece rolls and the drive system safely above the water line while maintaining perfect alignment with the slots in the SAMLA lid.

Core Design Features:

• Axle Notches: The four U-shaped cutouts at the top allow the clean and dirty fleece axles to drop into place. This makes swapping out a used roll as simple as lifting the axle out, no tools required.

• Reinforced Motor Gantry: The motor gantry includes a dedicated mounting plate for the drive system. It’s built with added material thickness to provide a stable anchor for the high-torque motor, ensuring that the drive shaft stays perfectly aligned even when the ReefMat 1200 roll is at its heaviest.

• Structural Cross-Ties: Two horizontal beams lock the side panels together. This creates a rigid "H-frame" that prevents the weight of the ReefMat 1200 roll from bowing the supports inward.

• Rim-Lock Feet: The base of each leg features a snap-on profile designed to grab the reinforced edge of the SAMLA lid, providing a stable foundation that resists vibration.

Engineering Benefit: Gravity-Assisted Maintenance

By placing the motor and rolls on this bridge, you utilize a "Top-Down" maintenance approach. Any excess water from the dirty roll drips straight back into the bin through the lid slots, keeping your sump area dry and salt-creep free.

Step 8 - The Spindle System

To handle both ends of the filtration process, the build uses two distinct spindle designs: a Fixed Waste Spindle and a Self-Tensioning Supply Spindle.

1. The Waste Spindle (Top Part)

• Design: Features a precision-cut longitudinal slot.

• Function: This is the "dirty" side take-up. The leading edge of the fleece is fed through the slot to create a secure, no-slip anchor. As the motor turns, it winds the used fleece directly onto this axle.

2. The Self-Tensioning Supply Spindle (Bottom Part)

• Design: Features spring-like flexible members (the "cage" ribs).

• Variable Fit: These "springy" ribs are designed to compress as they are inserted into the core of the ReefMat 1200 (or equivalent) roll.

• The Benefit: Because the ribs provide outward tension, the spindle can securely fit a range of internal core diameters. It creates just enough internal friction to prevent the roll from "free-wheeling" or unspooling too quickly, acting as a built-in tensioner.

Step 9 - The Gearing

The Gearing: Precision over "Chatter"

The drive system uses a custom gear reduction between the 8RPM motor and the Waste Spindle. This design prioritizes motor health and mechanical precision over raw speed.

• Preventing Short-Cycling: At a 1:1 ratio, the motor would "twitch" on and off in 0.25-second bursts. This gearing forces the motor to run for 1 second or more per cycle, which prevents "chatter" and extends the life of the motor’s internal components.

• Increased Torque: The reduction provides extra leverage, ensuring the motor can easily pull the fleece even when it's fully saturated and heavy.

• D-Shaft Key: The drive gear features a "D-shaped" bore to match the motor shaft, providing a high-strength mechanical lock without the need for set screws.

Step 10 - Motor & Housing

Motor & Protective Housing

The drive system is powered by a high-torque 6V-12V DC Worm Gear Motor. To ensure the motor lasts in a saltwater environment, it is encased in a custom-designed Motor Housing.

• The Motor: An 8RPM worm gear motor was chosen for its massive torque and its ability to "self-lock." This means the weight of the wet fleece can't pull the motor backward when it’s turned off.

• The Housing (Left): This enclosure protects the motor and wiring from salt spray and humidity. It features internal shelf-supports to hold the motor perfectly level with the drive gear.

• Snap-Fit Security: Just like the screen assembly, the housing lid uses Integrated Locking Tabs. These allow you to "click" the housing shut or open it for maintenance without fumbling with tiny, rust-prone screws.

• Wire Management: The housing includes a dedicated exit path for the power cables, ensuring they are routed away from the moving gears.

Step 11 - Float Switch

The Float Switch: Automatic Trigger

The Float Switch acts as the "brainless" automation for the system, triggering the motor only when the fleece is clogged.

• Simple Inline Logic: This is a basic inline switch. To wire it, you simply splice one of the two power wires leading to the motor and connect the float switch in between. When the float rises, the circuit closes and the motor runs.

• Magnetic Trigger: As the fleece traps waste, the water level in the bin rises. This lifts the magnetic float, completing the circuit to the 6V/12V motor.

• Self-Regulating: Once fresh fleece is pulled through, the water level drops, the float falls, and the motor stops instantly.

• Lid Mounted: It is installed through a dedicated port in the SAMLA Lid, keeping the wiring high, dry, and away from salt creep.