PULL-FUGE is a manual rubber band powered Centrifuge, sure it takes more time and effort compared to commercial Hi-tech Centrifuges but much cheaper and can function better in hazard conditions.
It's a cheap solution for medical campaigns held in remote areas in underdeveloped or developing countries where no electricity and low budget field hospitals are expected.
Changes made to the "DremelFuge":
1- Swiveled tube slots same like commercial Centrifuges to ensure that the sediment sample won't mix again after stopping spinning.
2- Enlarged the wheel hub diameter to be tight fitted in the spinner top opening and also to ensure that its centric.
3- Narrowed the tube side access in the swivel carriages as after 1st print the tubes kept flying away at high speeds.
4- Made the tubes hole size less by 0.1mm from original diameter to be snug fit.
Changes made to the "Pull String Helicopter":
It's quite simple to start it from scratch even with more simple design, but why wasting the time while it's already there and functioning?
1- Modified the spinner head to suite the modified "DremelFuge" hub.
1- To make the rubber band last longer; Soak it thoroughly in talcum powder.
2- Use a strong long lasting string like a fishing line.
3- To avoid vibrations Swivel carriages should be balanced; all tubes should be placed and filled with approximately same volume.
1.Insert the Spinner in the handle.
2.Tie the string to the spinner upper hole.
String length not to be more than 50cm.
3.Pass the rubber band through the spinner end eye hole.
Rubber band size used is no.64 (3-1.2" x 1/4").
4.Force the 2 band loops down to the end of the handle then hook them with a pen or a stick.
5.Rotate the pen/stick around 15 turns holding the spinner from turning.
6.Release the spinner slowly keeping the string under slight tension winding it back until the band becomes straight.
7.Either print the knob from the original design (Pull String Helicopter) or use any other object as a knob.
8.Pull the string back winding the band 3 turns then tie the knob as close as possible to the handle.
9.Replace the pen/stick with the printed stopper.
10.Finally, insert the wheel with the tube swivel carriages through the spinner slots and you are ready to go!
All are ABS 25% infill and only the Spinner is 100% Infill
In the mean time I tested the PULL-FUGE with commercial clear Pineapple juice and after about 5 runs I got these suspended solids sediment.
Assembling swiveling Carriages perfectly fit.
2nd Trial with tubes filled with water.