How to Make a Cheap, Portable Magnetic Stirrer. DIY Manual.

What is Magnetic Stirrer and Its Purposes

A magnetic stirrer is a laboratory device that is used to stir or mix substances by using a rotating magnetic field. The device typically consists of a small magnetic bar (also known as a “flea”) which is placed in a container of liquid, and a magnetic stir plate or stirrer motor that generates the rotating magnetic field. As the magnetic field rotates, it causes the magnetic bar to spin, which in turn creates a vortex that stirs the liquid.

Magnetic stirrers are commonly used in chemical laboratories for a variety of purposes, such as:

Mixing solutions or suspensions: Magnetic stirrers can be used to mix solutions or suspensions in order to ensure that they are evenly mixed or dissolved.

Heating or cooling samples: Magnetic stirrers can be used in combination with a hotplate or a cooling system to heat or cool samples while they are being stirred.

Maintaining constant conditions: Magnetic stirrers can be used to maintain constant temperature or pH conditions in a solution by keeping the solution stirred and mixed.

Dissolving solids: Magnetic stirrers can be used to help dissolve solids in a liquid by providing a constant agitation that helps break up clumps or agglomerations.

Overall, magnetic stirrers are an essential tool for many chemical laboratory applications where thorough mixing and agitation are necessary.

DIY Magnetic Mixer For Home Laboratory

Laboratory magnetic stirrers can be pricey. If you are only occasionally using it for a home laboratory, it can be economical to construct your own stirrer from the beginning. Trust me, it’s a breeze! The small video below outlines the materials required and the processes to make it. Take a look!

Build A Magnetic Stirrer (Vortex Mixer)

Inventory of Components Required For Magnetic Stirrer
I would like to show off some of the items I’ve acquired from Amazon. Most of these items are probably already in your home and making your own magnetic stirrer can be cost-effective!

The necessary staff:

computer fan

Silent Computer Cooling Fan – 80 mm – 1 Pack $4.89

Ultra Quiet Blue LED Fan Cooling – 92 mm – 1 Pack $5.99

12V DC Computer PC Fan, 2000 RPM – 80/90/120 mm – 2 Pack $12.99

small magnets

A potent neodymium rectangular magnet block of 20-25 mm is ideal for this model, magnets that are smaller may not be sufficient for your apparatus.

Strong Neodymium Magnets Bars, 25 x 5 x 3mm, 30 pcs $11.99

Powerful Block Magnets 20x10x4mm, Hole 4mm, 6 pcs $8.99

Stirring PTFE bar magnet

PTFE Magnetic Stirrer Mixer Stir Bars, 7 Sizes, 7 pcs $8.80

PTFE Magnetic Stirrer Mixer Stir Bar Set, 2 sizes, 8 pcs $9.99

moldable plastic (polymorph, instamorph, shapelock)


Clear Acrylic Plexiglass Sheets, 5 x 7″ for 80-120 mm fan, 5 pcs $5.99


A method to energize the fan: AC/DC converter or AA Battery Container. I advise utilizing an AC/DC converter (you’ll comprehend why in a moment).

AC/DC Adapter 3-12V, Speed Controller, US Plug for Electric Fan $12.29

8 x AA Thicken Battery Holder Base Box with ON/Off Switch – 2 Sets $6.99

-superglue (cyanoacrylate)

Mini Hi-Temp Hot Glue Combo Pack with 10 Sticks $4.99

Hot Mini Glue Gun with Case and 20 Sticks $13.99

Gorilla Dual Temp Mini Hot Glue Gun Kit with 30 Sticks $14.99

Xyron Full Size Multi-Stick Glue Gun with 10 sticks $15.69

How a Magnetic Stirrer Works

A magnetic stirrer is a laboratory device that is used to create a rotating magnetic field. This field is used to stir a liquid or mixture without the need for a physical stirring element, such as a stir bar. Here’s how it works:

The magnetic stirrer consists of a rotating magnetic field generator, usually in the form of a motorized magnet, and a stir bar, which is a small magnetic bar.

The stir bar is placed into the liquid or mixture that needs to be stirred.

The magnetic stirrer is turned on, and the rotating magnetic field generated by the motorized magnet causes the stir bar to rotate in the liquid.

The rotating stir bar creates a vortex, which mixes the liquid or mixture and ensures that the contents are thoroughly mixed.

The speed of the magnetic stirrer can be adjusted to control the rate of mixing, and the direction of rotation can be changed by reversing the polarity of the magnetic field.

Overall, a magnetic stirrer is a simple and efficient way to stir liquids or mixtures in a laboratory setting, without the need for physical stirring elements that may contaminate or react with the contents being stirred.

Here I’d like to supplement the video guide with more pertinent information on how to put together a magnetic stirrer.

How to Assemble Magnetic Stirrer
I’d like to include additional crucial information in the video tutorial.

Point 1

Required components for homemade magnetic stirrer

Gather the following items as mentioned above: computer fan/cooler, neodymium magnet block, PTFE bar magnet, plastic stand, power adapter, glue gun or adhesive, container filled with water for testing.

Point 2

Optional: Cut the edges

I’ve trimmed two sides on my fan, since they obstructed with the plastic base fitting. That’s just a peculiarity of my cooler. In your situation this may not be essential.

Point 3

Attach the magnet block to the fan.

Attach the magnet block to the PC fan. One of the most difficult undertakings is positioning the magnets accurately. That is why take your time!

Select the proper side of the magnetic cube.

The poles of the magnet should be arranged horizontally. Through trial and error, I have determined that the larger side should be on top, and I have marked the poles with a black line to distinguish between them. This way, the two sides of the magnet will generate a magnetic field. An important note: when using circular neodymium disc magnets (8-10 mm) in size, you will need two magnets. One should have its north pole facing upwards and the other its south pole facing upwards. The magnets must be placed directly opposite each other.

Magnetic mixer with circular magnets

Point 4

Attach the base for magnetic stirrer

Include the stand. I fabricated it with a 3D printer. If a 3D printer is not accessible, any level surface like a plastic sheet, rigid cardboard or plexiglass can be employed for the base. ️It’s essential to remember: spacers are necessary to place between the fan and the upper stand because of the additional height (3 mm) caused by the magnet(s). Coins can be put here or extra small pieces of plexiglass on the edges of the fan.

Point 5

Activating magnetic stirrer

Operating your magnetic stirrer. The magnetic stirrer can be run using any power source the fan is ordained to. You can employ AA Battery Storage or more advantageous AC/DC Adaptor. Your fan should have two cables (red for affirmative and black for disapprobation). If it has three cables, just overlook the third one. ️There is no speed regulation if you use battery storage. With AC/DC adaptor your magnetic stirrer will be more dependable, accessible and speed regulation is feasible here. That’s why I propose to utilize AC/DC adaptor for your magnetic stirrer.

Turn on and examine.

Powering Your Magnetic Stirrer

Insert a PTFE Magnetically Stirred Bar into the jar of liquid, initiate it and assess.


Ready to Use Magnetic Stirrer

If you don’t want to devote time to putting together or you need to purchase ALL parts for such device you can look into pre-made magnetic stirrers on Amazon:

Magnetic Mixer 2500 RPM Speed Stirrer with 4 Stir Bars $24.99

Lab Mini Stir Plate Mixer, 3000 ml $26.99

Stainless Steel Magnetic Mixer with stir bar $29.99

INTLLAB Magnetic Stirrer with 7 pcs. stir bar Set and stir bar Retriever $39.99

ANZESER Magnetic Stirrer Hot Plate, 100-2000rpm Lab Stirrers $59.95

Digital Professional Scientific Magnetic Hot Plate Stirrer for Lab $239.99


In conclusion, building a cheap and portable magnetic stirrer is an excellent DIY project for anyone interested in science experiments or chemistry. This DIY manual has outlined the necessary steps and materials required to make a functional magnetic stirrer without spending too much money. By following the steps provided in this guide, you can create your own magnetic stirrer for use in your laboratory or classroom.

Overall, a magnetic stirrer is a valuable tool for mixing liquids in scientific experiments, and creating one yourself can be an exciting and rewarding experience. With the right tools and a bit of creativity, you can make a magnetic stirrer that meets your specific needs and saves you money. So, gather your materials, follow the steps provided, and enjoy the benefits of your homemade magnetic stirrer.