Fruit Tree Ant Moat Collar, 110 mm Inner Diameter

Description
A simple 3D printable ant moat for fruit trees. It snaps around a tree trunk or branch and holds a ring of water so ants cannot walk up the tree, walking up to their aphid farm.

This is a one-piece split collar with a flexible rear section and an M4 bolt clamp at the front. The inside is meant to be sealed against the bark with foam, sponge, rubber strip, weather seal, or similar soft padding. It does not need to grip the bark directly.

The default model has a 110 mm inner opening. In practice, it is meant for a trunk or branch around 60-90 mm diameter, depending on how much foam or padding you use. It can fit smaller trunks with thicker foam.

Materials
PETG is recommended. It has enough flex to open the collar and handles outdoor use better than PLA.

PLA may work for a quick test, but it is more likely to crack during installation and may deform outdoors. ASA/ABS may also work if printed well, but I have only tested PETG.

Hardware
Uses one M4 bolt and nut. An M4x25 or M4x30 should usually work, depending on washer/nut choice. You can also just glue with sealant.

Seal / Padding
For the inside seal against the tree, use something soft and compressible, for example:

• Open-cell foam
• Sponge strip
• Pipe insulation foam
• Weather stripping
• Rubber foam tape

For sealing the split or small leaks, useful options are:

• Butyl rubber tape
• Neutral-cure outdoor silicone
• MS-polymer sealant
• Glue
• strong tape

Print Notes
Print flat as oriented. PETG, 2-3 walls, decent layer adhesion, and no supports should be needed. The part is designed with thin walls and a flex waist, so avoid brittle/under-extruded prints.

Open it slowly when installing. It's much easier to twist it slightly while opening rather than pulling the split straight apart.

Use Notes
Fill the moat with water after installation. Check occasionally for evaporation, debris bridges, algae, or foam touching across the water path. Ants only need one dry bridge to get across.