The Ikea Bittergurka watering can is decently cheap and very pretty, but the functionality is terrible. Trying to grow some sprouts, we needed a gentler watering solution than “spill the entire can all at once.
This design is two parts: a shower head that fits over the can’s normal spout, and a lid printed from TPU that makes a watertight seal. Because the spout comes up so high, it’s almost impossible to get more than a trickle out of the shower head without spilling. The TPU lid allows you to fill the can all the way up, and pour at whatever angle you like with full shower pressure and no spillage.
A first version of the design had a 100mm shower head and 2mm holes, which proved much too large on both counts: water poured out just as fast as without the attachment, and coalesced into one strong stream anwyay.
The final version has a 50mm shower head diameter and 1mm holes. These had to be opened up with a 1mm drill bit as the printed plastic mostly closed up.
A quick tip if you’re using a drill bit too small for your chuck to hold: wrap the base of the bit in an even layer of tape until it’s large enough. I used kapton which seems pretty much ideal, but I imagine scotch tape or packing tape would make a close second. Such a small bit probably won’t require enough torque in the drilled material for the tape to be an issue. Certainly not in 3D-printed plastic.