magstir-hotplate

An open-source hardware dseign for building lab-grade magnetic stirrer hot plates.

This is under development - check back later for the result!

Organization

• Lit review can be found at: appropedia.org/Literature_Review_for_Open_Source_Hot_plate_and_Stirrer
• The zotero group for the lit review can be found at: zotero.org/zotero.org/groups/5827095/magstirhotplate
• The source files are stored all on GitHub at github.com/uwo-fast/magstir-hotplate

Goal

Create a generic, low-cost, open-source magnetic stirrer hot plate for laboratory use, capable of reliable and precise stirring and heating for chemical, biological, or other experimental applications.

Requirements

• Adjustable stirring speed and temperature through intuitive interface
• RPM range: 50–2000 RPM
• Temperature range: 25°C–300°C
• ±1°C temperature accuracy
• Compact and portable design
• Corrosion-resistant and heat-resistant materials
• Modular design for scalability and repairability
• Safety features (overheating protection, spill resistance)
• Build cost target: <$100

Conceptual Design

• Processor: Budget MCU dev board (maybe QT or XIAO for size) to control system functions
• Motor: DC or stepper motor with encoder feedback, capable of 50–2000 RPM
• Heating Element: 6" surface burner resistive element (oven-top style)
• Temperature Control: Solid-state relay or PID-based controller for precise temperature regulation
• Control Interface: Potentiometer or encoder for setting speed and temperature, LCD/LED display for real-time temperature and RPM feedback
• Power Supply: 110–240V AC mains input, AC/DC converter to supply low-voltage power (e.g., 12V DC)
• Magnetic Stirring: Neodymium magnets mounted on motor shaft for reliable stirring
• Hot Plate: Off-the-shelf stainless steel dish with 6" coil mounted inside and back filled with ceramic insulation
• Thermal Barrier: off-the-shelf stainless steel plate with standoffs connecting up to hot plate and down to housing to isolate sensitive parts
• Component Housing: 3D printed from high-temperature materials (e.g., ASA or PETG)
• Safety Features: Overcurrent protection (fuse), thermal cut-off (software control), spill-resistant (enclosure design and overhang the plate)

Reference Designs

• HomeBrew DIY Magnetic Stirplate kit
  • v1: https://www.thingiverse.com/thing:307404
  • v2: https://www.thingiverse.com/thing:632714
  • fan remix in scad: https://www.thingiverse.com/thing:2187595

Outstanding Research Items

• Determining motor torque requirement (motor selection, sigh)