This “Hotel” is made to use paper straws as nesting material for mason bees but you can also just use the casing, change the size or cut it to a different length and add your own material.

The straws can easily be changed when they are not suitable for another season.

At the moment I'm using two variations, one with three different straw sizes and one with the two biggest sizes of the three.

During some web research I read about a perfect tube length of 16 cm to get a maximum of eggs wich develop into female bees and the ends have to be closed. So my straws are 16.5 cm long since the plugs at the end are having a 5 mm depth.

Approximate sizes of the paper straw diameters in mm:

Big: inner 7.1 - outer 7.9; medium: inner 5.1 - outer 5.9; small: inner 4.1 - outer 4.9

I printed the “Back” in PLA so that the bees won't chew on pure plastic, the rest is printed in PETG - all in 0.2 mm with a 0.4 mm nozzle, gyroid infill at 15% to 25% in my different experiments.

6 hotels are already in use at 4 different homes and 2 at my place are fully booked.

Assembling (see picture 4 to 9):

To assemble the Hotel, you first guide the straws through the “Sorter” and push them onto the plugs of the “Back”.

Then you can pull the sorter as far as about 1 cm up to the open end of the straws (best do it “open-end-of-the-straws” down on a table so the straws stay in place).

Now you can insert the frame with the straws into the casing (first “open-end-of-the-straws” down, then push on the ends until the frame reaches the back) and after that install the “Front” (so that the straws can't be pulled out one by one).

The “Bars” work as an extra protection against hungry birds and the fit directly on the “Front”, but better install it after all or most of the tubes are fully filled. Without the “Bars” it's a lot easier for the bees to find the holes.

If you want to use the whole model: Please always cut and print some tests with your slicer since every filament behaves so differently so that you sometimes have to resize parts for the best and smooth fit.

If you need different diameters for the straws, feel free to contact me as long as i don't find the time to publish my fusion360-files which are still looking very chaotic at the moment.