Here are the pics of my bee vac.
I have it standing on end for the pic but normally it would lie flat. The white tape looking stuff are strips of stick on draft excluders. A bee box sits on the tape and is hopefully sealed in. Whatever is used for a lid to the bee box must be sealed as well. I sized the bee vac to take either 5 frame nucs or 8 frame hive bodies.
The screen is not particularly clear in this pic but the hammer is leaning on it. Behind the screen is a baffle board designed to spread the airflow evenly through the screen. Seems to work OK. Both the screen and the baffle are set at an angle to even out the airflow.
The side view gives an idea of the shape. The whole thing was bodgied out of bits of ply and scraps of softwood. I wanted to make the vac as light as possible.
This is the vacuum tube end of the bee vac. I had trouble with bees making their way back into the clear vacuum tube after I had switched off the thing. I made up this light trap so I could run the vacuum through it and then turn it off. With no light at the end of their tunnel, bees were less inclined to wander out of their box.
Here's the view into the vac from the open vacuum tube end. You can get an idea of the slope of the screen. It goes from full depth at this end to nothing at the other.
This is the motor end of the vac. I designed it for two air pump style motors but these were unsatisfactory. They use brush type motors designed for intermittent use and not really efficient enough for this application. I've bought some little Chinese 12V brushless blowers and am in the process of installing them. I use an 18V lithium power drill battery and on the right of the pic you can see the connector I bodgied up. The battery works fine. To start with, I ran the power through some ss wire to drop the voltage to 12.
It works OK but I bought a device called a "buck converter" to replace it. Only costs a few $$ and it makes much more efficient use of the energy in the battery. I have yet to install it and the additional, efficient blowers.
As you can see my bee vac is a work in process but I'm very slowly getting there.