Harm Reduction I made a really easy and cheap DIY magstir! Great for volumetric liquid dosing, and HR!

[Dead Machination]

I just finished up making a magnetic stir for small bottles. It works great for making CBD tinctures or whatever else needs to be stirred overnight.

The system is basically a 12 volt power supply, connected to a heating pad with a switch (it gets up to about 165°, is much more efficient when you place a small sheet of tin foil over the top of everything to hold the heat in), and also to a cheap PWM controller that can slow the motor down. The motor is a standard 12v computer fan, with a magnet North Pole up on one side and South Pole up on the other, glued to the motors center surface about an inch apart to provide the rotating magnetic field. Mine is designed to fit "airplane bottles" but this could very easily be scaled up. PCB standoffs were used for the motor mounts, and the PWM controller was a cheap one from Amazon that I hadn't lying around from another project. The bottle stands on its own, but I decided to give it a wrap with steel wire for support. Total cost was free for me, because I already had the parts, but if you were to buy them it would be under $20, and you could definitely scavenge most of them, fans are in just about any broken electronic, and you only need a few small scrap pieces of wood. The magnetic stirrer really the only thing you need to purchase, and those are only a few dollars.

Here's the "schematic"

It actually works better than I could have ever imagined, I can get the stir bar to spin around halfway up the bottle on full speed, and it gives a perfect whirlpool at lower speeds.

I built it because I had a regular magnetic heat stir, but it broke right when I needed it, and Amazon took a while to get here.

I figured making a cheap magnetic stir that's able to achieve homogeneous mixtures is definitely in the interest of harm reduction.

 

[Cheshire_Kat]

I just finished up making a magnetic stir for small bottles. It works great for making CBD tinctures or whatever else needs to be stirred overnight.

The system is basically a 12 volt power supply, connected to a heating pad with a switch (it gets up to about 165°, is much more efficient when you place a small sheet of tin foil over the top of everything to hold the heat in), and also to a cheap PWM controller that can slow the motor down. The motor is a standard 12v computer fan, with a magnet North Pole up on one side and South Pole up on the other, glued to the motors center surface about an inch apart to provide the rotating magnetic field. Mine is designed to fit "airplane bottles" but this could very easily be scaled up. PCB standoffs were used for the motor mounts, and the PWM controller was a cheap one from Amazon that I hadn't lying around from another project. The bottle stands on its own, but I decided to give it a wrap with steel wire for support. Total cost was free for me, because I already had the parts, but if you were to buy them it would be under $20, and you could definitely scavenge most of them, fans are in just about any broken electronic, and you only need a few small scrap pieces of wood. The magnetic stirrer really the only thing you need to purchase, and those are only a few dollars.

Here's the "schematic"

It actually works better than I could have ever imagined, I can get the stir bar to spin around halfway up the bottle on full speed, and it gives a perfect whirlpool at lower speeds.

I built it because I had a regular magnetic heat stir, but it broke right when I needed it, and Amazon took a while to get here.

I figured making a cheap magnetic stir that's able to achieve homogeneous mixtures is definitely in the interest of harm reduction.

Nice !

 

[negrogesic]

While it's fun to make things like this (seems like something I'd make back when I was wired on large amounts of methylphenidate 24/7), you can get a magnetic stirrer on amazon for like $20.

But I get it things like this are cool to make. I made one once years ago out a computer fan and little magnets but it only had one speed.... "on".

 

[G_Chem]

Yea back when a mag stirrer would cost 1-200 this is worth it, but they are stupid cheap these days. Nonetheless super cool.

The one benefit here in terms of HR, if you live in a country or place where buying a mag stirrer could cause suspicion, then this thread is for you.

-GC

 

[Dead Machination]

The one I've got was about $70 on Amazon, and while it has a heating pad, it's wildly unregulated, and concerns me with how hot it gets. I actually usually end up using the silicone one instead. It does work much better for large containers, but for small ones, this one actually works better, and the heat is much more controllable. I also have a thermostat I could add to it to keep the heat exact, but for what I need, the heating pad stuck up against the side with foil works just fine, it gets the liquid up to about 120-130°f.

For me, it really didn't matter what the parts cost. I needed a stirer right then, and my other one just broke, it just completely stopped stirring anything. I had everything I needed already sitting around (I work on electronics professionally, and as a hobby, so it would be weird if I DIDN'T have a PWM controller, fan, heating pad, and some wires.) All of the parts were left over from other projects anyway, most of them came in multi packs and we're just sitting on a shelf gathering dust.