Picture of How to make a Self Priming Centrifugal Pump
This is a centrifugal pump that only needs to be primed before pumping begins then it can continue on it's own.

To make this pump you will need:
-Threaded rod (driveshaft)
-Hose adaptor
-Hose/ Tubing
-Sheet of neoprene
-2x sheets of plastic 
-1x plastic disc(laser cut)
-bottle neck and bottle cap
-19x nuts and bolts
-38x washers
-3x wooden blocks(moulds to be vacuum formed)
-thin sheet of aluminium
-hot glue gun
-waterproof sealant

-epoxy resin

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Step 1: Backplate

Picture of Backplate
1) On the back plate mark out where the 3 inner components (impeller and 2 blocks) are going to go, as well as the outer shape of the pump.
2) In the centre of where the impeller will go, mark out and drill a single hole for both the inlet hose and driveshaft.
3) Attach hose adapter through the inlet hole.

Step 2: Outer Casing

Picture of Outer Casing
Outer Casing
1) Create a 'tear-drop' shaped mould(the wooden block pictured) for the casing of the pump's face from a block of wood. Again vacuum form this.
2) With a waterproof sealant, seal around the edges of the casing where holes may have occurred from the vacuum forming process.
3) Drill an outlet hole at the top of the 'tear' shaped casing and attach a bottle neck using a glue gun.
4) Make sure  to keep an edge of plastic around the shape that has been vacuum formed (for bolts). 

Step 3: Inner Shapes

Picture of Inner Shapes
Inner Shapes
1)Create a mould for the inner shapes from wood. These should be as thick as the mould for the outer casing.
2)These wooden blocks are then to be vacuum formed to create the shapes inside 
3)Glue inner shapes onto desired position on the outer casing
4)Place the backplate over this, if the inner shapes do not touch the backplate layer it up with something like wood or plastic with the desired thickness that will allow this.
Shujon4 years ago
Does that means without any power???
scoochmaroo4 years ago
This is great. What do you use it for?