Endo - 15-4-2020 at 17:37
So, I was given one of Ebay post for same model by a neighbor who was moving, along with a small retort, and some old ground glass stoppered reagent bottles with raised
lettering and a liter of DMSO.
I checked it out and it heats and controls heat fine, however the motor for stirring is very rough and sounded like it needed cleaned badly.
I got it apart (PITA) and found that there is a simple gear box that reduces down a shaded pole motor. However the gears have seen a lot of wear.
Knowing that this thing is ancient and no aftermarket parts are available I thought I would check to see if anyone out there might have a
gearbox/motor laying around in a bin that they would be willing to part with. I figured it wouldn't hurt to ask before I start trying to figure out
how to fit a more modern alternative to drive the magnetic stirrer.
Thanks!!
p4rtridg3 - 16-4-2020 at 18:36
If I were you I would just hook up a modern replacement motor. Not worth trying to find the exact gearbox.
draculic acid69 - 16-4-2020 at 18:59
They had one that was the exact same shape on an episode of CSI that cult up and caused an explosion.really weird how it's so tall for such a small
looking hotplate.
Tall and thin rather than short and fat.
Heptylene - 17-4-2020 at 05:10
Maybe forget the gearbox and adjust the speed of the motor directly? Using a variable frequency drive. The motor is probably low power so a VFD
shouldn't be too expensive.
Endo - 17-4-2020 at 15:21
Great Idea Heptylene. I will look into it, it may be easier to core out the gear box and clamp on one of those 3d printer couplings. The other idea
was to decide if I can cram a stepper motor, power module and an appropriate stepper driver in there (maybe a arduino pro mini).
Endo - 17-4-2020 at 16:06
Looks like a DC motor, pwm controller, and coupler only sets me back 13$ Should all fit too 