Miniature Dam With Mechanical Doors

A tabletop dam (or model dam) is a scaled-down version of a real dam built for demonstration, education, or testing purposes. Here's a step-by-step process to build a tabletop dam using simple materials.

I build this model in 5 Parts.

1. Foundation ( Step 1 - 6 )
2. Spillways ( Step 7 - 8 and 11 )
3. Side Walls ( Step 9 - 10 )
4. Bridge ( Step 12 -13 and 16 )
5. Gate Lifting Mechanism ( Step 14 -15 )

We need following materials for making this dam.

1) 2-3 mm steel wire

2) Cement

3) Sand

4) Sunboard sheet

5) 10 RPM gear dc motor X 2

6) 6 mm steel rod

7) Water

8) Tweezer

9) Silicon tube

10) Electric wire, Push switch and Battery

Sketch the dam structure on paper – include base, walls, spillways, and reservoir. Starting with a tabletop model of a dam, I create a dam between two heels by placing soil and a heel on the table.

Dig the site to the required depth to remove loose soil and reach a stable base for dam construction. Cut 2mm steel bars to required lengths as per the structural design drawings using cutters. Place steel bars (rebar) in the excavated base to strengthen the concrete foundation and resist structural loads.

Bend the bars into rectangle using bending tool according to bending size. Follow the grid pattern and spacing requirements ( 2 cm ) from structural drawings.

Then run each of the 40 stirrups through horizontal bars. There is a 2 centimeter space between each stirrup. Next, secure each strip with a wire and tweezer. The process takes a long time.

Install additional steel reinforcement at the locations where gates will be installed for added strength and durability.

To make other reinforcement cut steel bars to the necessary lengths in accordance with the design. Tie intersecting bars using binding wire to maintain the correct position during concrete pouring. Ensure proper spacing, lap length, and alignment of bars.

I use sunboard (3–5 mm thick) sheet to make shuttering.

Sunboard (also called foam board or PVC foam sheet) is a lightweight, rigid material often used in modeling and architectural prototypes. It's easy to cut and shape, making it ideal for miniature construction projects.

Cut Sunboard sheet in size and place both side of reinforcement. Glue sunboard pieces together to form a dam mold. Use clear tape or silicone to seal inner seams if pouring liquid. This prevents leaks and keeps edges clean.

Give support from ground to shuttering using bamboo stick.

Creating miniature concrete requires adjusting standard concrete mix to work at a small scale. it should be fine-grained, easy to pour, and strong enough for model work.

Ratio :

1. White cement or grey Portland cement – 1 part
2. Fine sand (sifted or river sand without pebbles) – 2 parts
3. Water – as needed (just enough to make it pourable)

Make sure it's very fine and has no pebbles or lumps. Use a fine mesh strainer if needed. In a small bowl or cup, mix 1 part cement + 2 parts sand. Stir thoroughly for even distribution. Add water drop-by-drop and mix. The mixture should be like thick batter, not watery. It must pour but also hold shape.

Pour into Mold :

1. Gently tap or vibrate the mold to remove air bubbles.
2. Let it cure for at least 24–48 hours (longer = stronger).

After 24 hours Gently remove the shuttering/sunboard. Now make reinforcement for spillway as per picture.

Prepare formwork for the spillway channels which will carry overflow water safely downstream.

Create Gate Slots for placing slider gate between this formwork. Glue sunboard pieces together to form a box. Use silicone to seal inner seams if pouring liquid.

Give support to all formwork for unify spacing between them.

Pour concrete into spillway forms and remove shuttering after curing ( 24 hours +++) to complete the spillway wall.

Then remove formwork carefully.

To make side wall reinforcement cut steel bars to the necessary lengths in accordance with the design of wall. Tie intersecting bars using binding wire to maintain the correct position during concrete pouring. Ensure proper spacing, lap length, and alignment of bars.

Install rebar for the dam's side walls to provide strength and support against lateral water pressure.

Construct formwork for the side walls and pour concrete, then allow curing before removing the shuttering.

Prepare formwork for the spillway channels which will carry overflow water safely downstream. Pour concrete into spillway forms and remove shuttering after curing to complete the spillway surface. Smooth and waterproof the spillway surface; install any required channels or energy dissipation structures letter.

Build the road deck over the dam using reinforced concrete to allow vehicle and pedestrian passage.

Follow this steps :

1. Formwork
2. Reinforcement
3. Pouring Concrete
4. Leveling

Remove spillway formwork. Take down the formwork once the bridge slab has gained sufficient strength. Install any required channels or energy dissipation structures as i called you in step 11.

Mount the electric motor that will lift and lower the sluice gates to control water flow.

Fit the sliding door into the guide rails to regulate water discharge. Connect this door to shaft of electric motor. Ensure all mechanical and electrical systems are correctly aligned and operational.

Fit metal and plastic railings along the bridge edges for safety.

Allow water to fill and pass through the dam to test flow control, gate operation, and spillway performance.