Centrifugal Water Pump

Hot off the smoking Anet A8! :)

After being given a broken Anet A8, complete with melted wires, I set about fixing it and upgrading it with Marlin Firmware, level sensor and flexible steel print bed.

This is my water pump design; with the main aim being to teach myself 3D design and 3D printing. Also figured that I might as well make something useful; as I needed a small water pump to remove water that collects under the house. Also a good test of PLA in quite harsh conditions; the dirty pump in the picture has been in use for nearly a year.There's no pump curve or other engineering design behind it; it's just made to fit the small space and the size of the hose I had.

There's a Version 2 & Version 3; Version 1 didn't work so I haven't bothered to upload it. Version 3 has a bigger outlet and a thicker lid. Also tidied up the way it was drawn around screw holes etc.

I recommend that for both that you use the short impeller; it actually moves more water. The tall impeller pushes too much water with the motor I'm using and just back pressures the pump housing.

In this application the pump sits on long screws and is always underwater. The motor sits above water and is triggered by a float switch from a boat store. I also use a DC speed controller with soft start; connected to an old 12VDC battery, as the current draw from the motor is up to 18 Amps.

(ps: Can't figure out the Thumbnails bit, so not all images are present)

8th Feb 2020 - Its raining hard at the moment, so finally got around to putting V3 pump under house. Took a pic of the V2 pump that was in place for quite a few months, to show how dirty the environment it's in.

8th Sept - Neglected to mention there is a hexagonal recess in the impeller that suits an M4 hexagonal bolt or nut. I'm using the M4 bolt as the drive shaft. Also there is hexagonal recess in the lid; which allow for two 5/32" brass nuts to be inserted. Drill these out to 4mm and so they act as bearings.

28th Dec 2020

Added a pic of the taller water pump and the file for the extra long collar. This is to get the pump motor away from the water. For the shaft use a 4mm threaded rod and a nyloc nut; cut it to size.

3rd Nov 2021

Added two straight bladed impellers. A quick bucket test of the one with the short blades shows that it moves a lot more water than a curved bladed impeller.

2nd Jan 2022

Happy New Year Everyone. Slight update to the Ver 3.1 pump housing. Version 3.2 has a longer transition (or loft) to the outlet, to help for smoother flow. Also the outlet is longer to help keep the hose on and to allow room for a hose clamp to fit.

Hope to make a bigger version (Ver 4) soon with 3/4" and 1" outlets.

17/01/2022

Introducing Versions 4 & 5 of the water pump. Both are scaled up from the Ver 3 and modified to make them about the right size.

Version 4 has a 19.5mm (3/4") outlet; but uses the Ver 3 cover, impeller etc. To keep it simple all the parts are in a Zip file.

Version 5 has a 25mm (1") outlet. It has it's own size of cover, impeller etc. All the parts are also in a Zip file. Version 5 also uses a bigger motor, it is based on this one from a local electronics store. https://www.jaycar.com.au/standard-high-power-d-c-motors-10200-rpm/p/YM2776

• DC Motor is a "770" style motor from a local electronics store.

https://www.jaycar.com.au/standard-high-power-d-c-motors-11800-rpm/p/YM2770

• Soft starter / DC motor speed controller

https://www.ebay.com.au/itm/Speed-DC-Motor-Controller-Governor-Module-Digital-DC-brushed-21KHZ-Set-New-Hot/123860910294

• Drive shaft for the impeller is a 4mm hex headed bolt; which press fits into the impeller
• Pump lid or cover has hex recesses in it as well. Use 5/32" brass nuts pressed in as bearings and drill them out to 4.5mm
• Coupling for motor to drive shaft is a solid brass one off eBay, like this one.

https://www.ebay.com.au/itm/5Pcs-Bass-Motor-coupling-Motor-Drive-Shaft-Coupling-Coupler-Connector-Sleeve/113961381587?hash=item1a88a0aed3:m:mAyGtqxiGOuKpDrUEzpXsjQ

• Print with 1.2mm shell (4 layers) and 30% infill
• No support, except for pump housing
• No brim or raft needed, unless you have warping problems

Print Settings

Printer Brand:

Anet

Printer:

A8

Rafts:

No

Supports:

Yes

Resolution:

0.2mm

Infill:

30%

Filament: Any PLA

Any colour as long as its black!

Notes:

Use support on Pump Housing only.

No Brim or raft needed, unless you have warping issues.

How I Designed This

Using OnShape

When OnShape was easy to sign up with for Free! Also OnShape doesn't require any software installation on your computer.