WaterWise: Calibrate your sprinklers

This catch cup is a calibration tool for sprinkler and irrigation systems. Stake it into your turf, run your sprinkler for a set time, then read the collected water level off the embossed markings on the cup wall. It measures from 0.5 to 2.5 cm in 0.5 cm increments, which gives you enough resolution to actually diagnose differences between zones and see if your in-zone coverage is even.  This will let you dial in a target application rate instead of just guessing.

The design is two parts: the cup body with the integrated measurement markings, and a hexagonal spike insert that press-fits into the side of the cup and anchors it upright in the ground during a run. Printing a batch of these at once lets you spread them across multiple spots and check uniformity in a single test session.

Printing

Any PLA or PETG will work. I printed mine in PLA and the fit and embossed markings came out clean. The spike is a hex press-fit into the cup body.  If the spike prints slightly too large/small scaling it to 100.5% or 99.5% should work.  No supports needed for either part.

Assembly

Press the spike insert into the hex socket on the side of the cup. It should seat firmly without needing a lot of force. If it binds before seating fully, scale the spike down slightly and reprint.

Using It

Push the spike into the turf so the cup sits level and won't tip over mid-test. Run your sprinkler for a consistent timed interval (20 to 30 minutes is typical) and then read the water level directly off the exterior cup markings and/or use a ruler into the cup. Running several cups at once across different areas in one pass and putting the data into a spreadsheet is the most efficient way to spot uneven coverage or over-watered areas before you've burned through a season of water bills.

3MF and STEP included