28mm caravan RV sink water drain pipe connector fittings

thingiverse

UPDATED 11th March 2020: Added straight-through Y pattern, optional flow arrows. Having an Australian-built caravan with European plumbing in Australia, I found it quite challenging to source the 28mm diameter sink and drain pipe fittings that are standardly fitted. I tried a few of the local big-name Australian caravan parts suppliers who claimed to offer a wide range of pipe fittings, but they were unable to assist me. I managed to find some available on UK eBay, but the cost was exorbitant - over 48 AUD (approximately 32 USD / 28 EUR / 24 GBP) for just one single connector posted to Australia. This was unacceptable. In frustration, I decided to create my own workalike connectors. Presented here is a set of 28mm dia fittings for straight-through, tee, Y, straight-through Y, elbow, end cap, U-bend, X, multi-pipe and reducer patterns so you can make your own. Alternatively, you can adjust the design to fit any pipe diameter you like. For acute Y angles, the connector length may need to be increased to prevent pipe end impingement. The end cap comes with a string tie loop by default but can be disabled. The photos demonstrate the straight-through, 90 elbow, tee and end cap prints, as well as how I used them when re-routing the sink drain piping. Customiser variables The OpenSCAD script is highly customisable, so feel free to create these for practically any size pipe you prefer. You can also modify the script if you require an elbow angle other than 90, 45, 30 or 20 degrees. The rendered screenshots show the customiser settings used to produce them. CONNECTOR_TYPE straight, tee, X, Y, straight-Y, multi, 90 elbow, 45 elbow, 30 elbow, 20 elbow, 120 elbow, U bend, cap, reducer PIPE_ANGULAR_SEPARATION 60, 75, 90, 100, 110, 120, 125, 130, 135, 140, 150 degrees TO_SUIT_PIPE_DIAMETER Set to your plastic pipe's outside diameter (these connectors fit over the outside of the pipe) STRAIGHT_CONNECTOR_LENGTH Overall length of the connector (e.g. end-to-end for straight) PIPE_OUTERMOST_DEPTH The first-from-end inside length (at pipe diameter) PIPE_NOMINAL_WALL_THICKNESS Change to suit how thick and thus strong you want the connector wall to be. Nominally 2mm thick. PIPE_INTERMEDIATE_STEP_REDUCTION The tiny diameter difference inside the pipe, to grip it more firmly (optional, set to 0 if not wanted) PIPE_INTERMEDIATE_DEPTH The length of the innermost step diameter EMBOSS_SIZE_LABEL Print the fitted pipe diameter on the outer ends of the connectors if desired e.g. "28mm Ø" EMBOSS_ANGLE_LABEL Print the angular separation (note - only use for Y fittings so far) EMBOSS_FLOW_DIRECTION_UP Print a large upwards arrow on the outside in the middle of the connector length for most patterns EMBOSS_FLOW_DIRECTION_DOWN Print a large downwards arrow on the outside in the middle of the connector length for most patterns TEXT_SIZE Embossed text size. Nominally 5mm high. Highlight with black Sharpie marker on print. CAP_TIE_LOOP Add a small loop to the end cap for tying or looping a retainer string onto. TO_SUIT_REDUCER_PIPE_DIAMETER The secondary pipe diameter for a reducer fitting. CROSS_SECTIONAL_DEMO Only check this to view the internals of the fitting. Don't use it for rendering or model generation. (see Reducer picture) PRINTING NOTE Print at 100% infill. Try and print standing vertically, if possible so that scaffolding may be omitted on the inside. These connectors are specifically designed for sink and drain plumbing only, as the filament I used (PETG) is not rated as food grade. If I had my preference, I would use Nylon, PETG, ABS in that order. I do not recommend using PLA as it may not remain waterproof. These connectors and the OpenSCAD script to generate them are placed in the Public Domain. As a courtesy, please leave my name as the author of the program. I do not warrant them fit-for-purpose for anything, so use entirely at your own risk.