Buchi Rotovap Inconsistent Spin Rate (Control Issue)
For anyone who is a heavier user of their Buchi, you might start running into an issue where the speed control knob is erratic, changes speeds regularly, or drifts around.
There is an internal potentiometer that is a very easy fix, and it's a readily available part - Bourns PCW1D-R24-EAB503L - $10
This is an easily damaged part when these things are shipped. All it takes is a good knock to the control knob and that's enough to start causing issues. If you are looking to buy a used one, if the knob is missing on the unit, I will guarantee you the pot is damaged and will cause problems.
It's pretty quick and easy to disassemble, remove the board, and desolder/resolder the new potentiometer.
If you thought the outside of this thing was impressive, wait until you see the interior build. Clear why this kit cost thousands of dollars when new.