3D printed connector for toilet flush inlet valve

I noticed there our toilet flush was running a fine stream all the time.  Upon investigation, I found that the inlet valve was not able to close properly when the cistern was full, and the excess water was leaking as overflow.  There was a sticker under the lid with a web link and references to part numbers, so I thought I could just order a new inlet valve and replace it.  The website didn't exist, which meant that the company probably didn't exist any more.  I went to ScrewFix to buy a generic one for replacement, only to figure out that the type I needed could not be replaced by a generic one - they had side entry valves, and bottom entry valves - the one I needed was designed as a clip-on inside the cistern, a mini version of the bottom entry valves.  The replacement bottom entry type valves were too long to fit completely inside the cistern, but I could fit a side entry valve inside the cistern if I could somehow fix it in position.  So I bought a side entry valve.

One option was to use polymorph, or I could put my new 3d printer to some use and create a custom part.

CAD model

I designed a two part connector to fix the side entry valve on the cistern clip in AutoCAD.  Since it's hidden from the view, its look was irrelevant, it only needed to be strong enough and functional.

Printing the 3d model

I exported the parts in .stl format.  I exported them separately as experience taught me that the low cost 3d printers have lots of problems while printing and often the prints get missed up half way and you've to restart the prints - if you are printing multiple parts, and one of them is causing problems then it ruins the other parts too.  Therefore, printing the parts separately saves time, effort, and material.

I imported the .stl files in MakerWare, the free software by MakerBot.  Since the surface finish was immaterial, I sectioned the models at low resolution of 0.3mm layers, and exported the toolpaths for printing from a SD card.

Printed parts and fitting

This picture is a close-up of the printed parts.

The printed parts with the new inlet valve on top and the clip holder in middle.

Fitting the first part in the clip.

Fitting the new inlet valve in the first part.

The second part secures the first part in the clip holder.

Side view of the completed assembly.

The new inlet valve clipped inside the cistern, working prefectly.


The major financial components in 3d printing is the cost of buying and maintaining the printer and time invested in designing and printing, the materials are quite cheap.  The printing itself is quite a slow process.  Estimated material cost only for this connector is about 75p, but the design and print time spans several hours.

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