These are klackers or noisemakers that print in place as one part! They make a great toy for kids but I also find them as a great fidget toy for adults too.
This a new version which is much easier to print. To have a successful print, most importantly you must have good adhesion to the bed. For the loudest klackers, more walls and infill the better but watch out for curling. If you have issue with curling, enable z-hop, or increase the amount of plastic after the tangency of the balls.
Getting them to Klack If you are having a hard time getting them to klack I found the easiest way to get them started is to set them flat on a table so the klackers are spread out and as you pick them up off the table whip them back down to make them klack. There are two techniques; the single klack and the double klack as demonstrated here.
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