Good news! The first prototype of my bowl feeder is ready! Finally I can do some tests and see how the mechanics are working!
It was an exciting moment to switch on the vibration for the first time, and to slowly increase the amplitude and try different frequencies. Unfortunately, the result was slightly disappointing: nothing happened.
At first I used 10mm long pieces of a cable isolation as a flexible support of the bowl. This caused the screwheads to be way too far away from the electromagnets to receive any magnetic force. My first step was to cut the supports in half in order to bring the screwheads closer to the electromagnets:
It worked, the bowl was receiving some force and was showing first signs of vibration. But not more than that. My next step was to replace the cable isolation pieces with pieces from a flexible rubber tube, also just 5mm in length:
Still no effect on the perler beads. Next, I unscrewed the screws a few millimeters to bring the screwheads closer to the electromagnets:
It worked, the bowl was now showing some real vibration. But still no effect on the beads. I did a lot of thinking and investigating and I think, the bowl is only vibrating horizontally, but not vertically. After all, the rubber tube can hardly be compressed. So my next step is to use springs instead of the rubber tube. I calculated the approximate force, compared force/displacement diagrams and then ordered two different kinds of springs.
I finally got the springs! Unfortunately, these are really tiny and don’t fit on the pins on the base and bowl feeder. I could use a file to reduce the pins’ diameter, but I’m not sure this will solve the problem that it is vibrating much more horizontally than vertically:
I think I will stop this approach at this point. I already have an idea for a different kind of support/suspension, with using flat spring.
Did you manage to get this working?