Bee hotel nesting block insert
Solitary bees pollinate a garden all season and need only a block of tunnels to nest. This insert is a 100 x 100 x 120 mm block with 30 tunnels of 6 to 8 mm diameter and 110 mm depth, closed at the back, a 1 mm chamfer at each entrance so wings do not tear, and a rim so several blocks stack inside a wooden housing. Print it entrance-up in PETG or ASA at 0.16 mm layers, since smooth internal bores matter and stringing must be avoided.
SpeakCAD adjusts tunnel diameters for the bee species in your region and sizes the block to your existing bee house or a rain-proof enclosure it can generate for you. Ask for split halves so you can clean it each winter. The preview is free in your browser.
Design a bee hotel nesting block 100 x 100 x 120 mm with 30 tunnels 110 mm deep in a staggered grid, diameters mixed between 6, 7 and 8 mm, a 1 mm entrance chamfer on each, a closed back wall 5 mm thick, and a 2 mm stacking rim.