Improved Tube and Culture Rotator

This is a small, easy to build, and cheap (under $70) culture/tube rotator that can be used to keep bacterial/fungal cultures in suspension, mix chemicals, keep items in suspension, and generally mix things. It holds 12 x 14 mL bacterial culture tubes, and is angled at 60 degrees to increase the surface area for oxygen absorption. The speed controller allows this to turn at speeds of ~2 RPM to 50 RPM. It is small enough to fit into a small bacterial incubator, or in a small corner of your lab.

This is an improved version of our original rotator. This new design incorporates a more powerful motor and gearbox, greatly extending the life of the rotator. In addition, a new base simplifies assembly and allows for easy repairs. This new design also eliminates all hardware aside from four 16 mm M4 bolts needed to attach the motor to the stand.

Short video of the rotator running: https://www.threads.net/@bryanheit/post/DG1FqHYzhsy?xmt=AQGzRsuTlADdsOoNIm2134FzKjhE7-8kGk1QaXhSA6H0Ag

Original Rotator: https://www.thingiverse.com/thing:6661590

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PARTS:

-4 each of the "Lab Rotator 2 - Supportsx4.stl" and 1 each of the other 3D printed components, . All can be printed flat on the bead without supports.
-4 x 16 mm M5 bolts
-1 x 12 volt wall adaptor, 2A DC, with a 5.5 x 2.1 mm plug
-1 x 5.5 x 2.1mm female DC Power Jack Socket Connector: https://www.aliexpress.com/w/wholesale-5.5-x-2.1mm-DC-Power-Jack-Socket-Connector.html
-1 x Mini 5A 90W PWM 12V DC Motor Speed Controller: https://www.aliexpress.com/w/wholesale-Mini-5A-90W-PWM-12V-DC-Motor-Speed-Controller-.html
-1 x 30 RPM or 50 RPM 12V Geared Motor: https://www.aliexpress.com/w/wholesale-turboworm-gear-motor.html
-Cyanoacrylate glue
-20-30 cm of electrical wire appropriate for 12VDC

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ASSEMBLY:

1) Solder short (~10 cm) leads onto the DC power jack.

2) Install the jack on the back the body.

3) Attach the wires from the power jack to the V+/V- terminals of the motor speed controller. Make sure to connect the + lead from the jack to the V+ terminal, and the plug ground to the V- terminal.

4) Screw the motor in place and run the wires through the hold on the front of the stand and into the electronics compartment. Attach to the M+/M- terminals of the speed controller.

5) Plug-in the power jack and make sure the motor turns and responds to the speed controller. If it doesn't, you most likely need to swap the leads on the V+/V- terminals.

6) Install the speed controller into the side-hole in the body.

7) Perform a final run test, and if the motor turns, put the lid on the base. This can be glued in place, but I would recommend using double-sided tape to allow for easier repairs.

8) Attach the supports to the upper disk by pressing the grooved surfaces together, then push the assembled unit into the lower disk. These should press-fit, but a small dab of glue at each connection is a nice bit of insurance.

9) Place the rotator onto the motor shaft - its ready to run! If desired, a small amount of glue can be added to the shaft, but we've found it convenient to be able to remove the rotor for loading and unloading tubes.