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Random Positioning Machine

Random Positioning Machine (RPM)

  • A scientific laboratory device
  • Enables simulation of reduced gravity conditions
  • Used in scientific research and education
  • AATC has designed, built and laboratory tested a RPM device
  • Device is available for sale
  • Target: research institutions, universities, educational centers, schools and companies
  • For inquiries, please contact at info@aatc.pl

About

What is a Random Positioning Machine (RPM)?

  • A scientific laboratory device
  • Enables simulation of reduced gravity conditions
  • Used in scientific research and education
  • Based on 3D clinostat technology

What is the operating principle of the device?

  • Two rotating frames (inner / outer)
  • Dynamic change of orientation -> averaging of the gravity vector
  • Controlled replication of reduced-gravity conditions in a laboratory

What modes does it support?

  • Randomization (microgravity)
  • Synchronization (planetary simulations)

What environments can it simulate?

  • Microgravity - 0G
  • Moon - 0.165G
  • Mars - 0.38G
  • Custom settings can be defined

RPM CAD project 1 RPM CAD project 2 RPM CAD project 3

Key Technical Parameters

Key technical parameters:

  • Dimensions: 30x30x28 cm, up to 38 cm in motion (12x12x11 inches, up to 15 inches in motion)
  • Control panel: 27x14x9 cm (~11x6x4 inches)
  • Sample mass: up to 400 g (0.88 lbs)
  • Maximum speeds: 200 rpm (inner), 150 rpm (outer)
  • Power supply: 12 V, up to 20 W (nominal 60 W)
  • Rotational limits: 200 rpm (inner ring), 150 rpm (outer ring)
  • Operating temperature: up to 70°C (158°F)
  • Can be used inside a cell culture incubator

Construction:

  • Aluminum and steel, technopolymer gears
  • Stepper motors 59 Nm/cm, step angle: 1.8°, TMC2209 drivers

Settings:

  • Microgravity 0G (60/60 rpm + random deviations)
  • Moon 0.165G (60/60 rpm, synchronized)
  • Mars 0.38G (two-stage mode: 60/60 -> 61/60 rpm)
  • Custom settings can be defined (range 0-1G)

RPM Settings Microgravity RPM Settings Moon RPM Settings Mars RPM Settings Custom1 RPM Settings Custom2

Expected simulation values for the microgravity setting

Effective gravity level:

  • ~10⁻³ to 10⁻² g (time-averaged residual acceleration)

Gravity vector:

  • Continuously reoriented, randomized in 3D space
  • Mean vector → ~0 over time

Angular velocity (typical):

  • Inner ring: ~60 rpm
  • Outer ring: ~60 rpm (with stochastic variation)

Residual acceleration sources:

  • Centrifugal effects (distance from rotation center dependent)
  • Mechanical imperfections and vibrations
  • Air drag (if not operated in sealed conditions)

Recommended operational conditions:

  • Sample positioned as close as possible to the rotation center
  • Symmetric mass distribution
  • Stable thermal and mechanical environment
  • Time scale for effective averaging:
  • On the order of seconds to minutes, depending on rotation profile and sample geometry

RPM Microgravity ISS RPM Microgravity Chart RPM Microgravity Distribution

Expected simulation values for the lunar setting

Effective gravity level:

  • ~0.165 g (time-averaged target acceleration)

Gravity vector:

  • Maintained as a constant resultant vector through synchronized rotation
  • Direction effectively stable in the sample reference frame

Angular velocity (typical):

  • Inner ring: ~60 rpm
  • Outer ring: ~60 rpm (synchronized mode)

Simulation principle:

  • Partial compensation of Earth’s gravity via coordinated rotation
  • Residual vector corresponds to lunar gravity magnitude

Residual acceleration sources:

  • Centrifugal components (radius-dependent)
  • Synchronization errors between axes
  • Mechanical vibrations and backlash

Accuracy considerations:

  • Dependent on precise phase alignment of both rings
  • Sensitive to sample positioning relative to rotation center
  • Typical deviation: on the order of 10⁻² g

Recommended operational conditions:

  • Rigid mounting of the sample
  • Minimized offset from the center of rotation
  • Stable rotational control and low-noise mechanical operation

RPM Lunar Moon RPM Lunar Chart RPM Lunar Schematics

Expected simulation values for the Martian setting

Effective gravity level:

  • ~0.38 g (time-averaged target acceleration)

Gravity vector:

  • Quasi-static resultant vector generated via slight desynchronization of axes
  • Stable magnitude with slow directional modulation

Angular velocity (typical):

  • Inner ring: ~60 rpm
  • Outer ring: ~61 rpm (two-stage / offset mode)

Simulation principle:

  • Controlled mismatch of rotational speeds produces a non-zero
  • Averaged gravity vector
  • Magnitude tuned to approximate Martian gravity

Residual acceleration sources:

  • Centrifugal effects (radius-dependent)
  • Frequency offset–induced oscillations
  • Mechanical tolerances, vibration, and control noise

Accuracy considerations:

  • Dependent on precise speed ratio (Δω) between rings
  • Sensitive to radial displacement of the sample
  • Typical deviation: on the order of 10⁻² to 10⁻¹ g

Temporal characteristics:

  • Slow precession of the effective gravity vector due to phase drift
  • Averaging timescale: seconds to minutes

Recommended operational conditions:

  • Sample positioned close to rotation center
  • Stable control of both angular velocities
  • Minimized structural vibration and thermal drift

RPM Martian Chart RPM Martian Distribution RPM Martian Mars

Applications and Advantages

Applications:

  • Cell biology, botanics, zoology, microbiology
  • Chemistry and pharmaceuticals
  • Space medicine
  • Materials engineering
  • Education and science outreach

Use cases:

  • Cell culture experiments
  • Gene expression studies
  • Drug research
  • Investigation of sintering cooling processes
  • Education and demonstrations

Advantages:

  • Compact design
  • Compatible with use inside an incubator
  • Reproducible experimental profiles
  • Predefined settings (microgravity, Moon, Mars)
  • User-defined parameter configuration

Peer-Reviewed Publications

  • Markiewicz M., Galanty A., Prochownik E., Kołodziejczyk A.M., Paśko P. (2025) "Innovative Production of Bioactive White Clover Sprouts Under Microgravity: Towards Functional Foods Supporting Prostate Health." Journal: Applied Sciences. Volume: 15(21). Page: 11668. DOI: https://doi.org/10.3390/app152111668

  • Markiewicz M., Galanty A., Kołodziejczyk A.M., Żmudzki P., Prochownik E., Zagrodzki P., Paśko P. (2025) "Bioactive compounds accumulation in Brassica sprouts grown under microgravity and darkness: a novel approach to functional foods." Journal: Food Chemistry. Volume 491. Page: 145324. ISSN: 0308-8146. DOI: https://doi.org/10.1016/j.foodchem.2025.145324

  • Markiewicz M., Galanty A., Zagrodzki P., Kołodziejczyk A.M., Paśko P. (2025) "Searching for Innovative Functional Foods: Correlation Between Chemopreventive Potential and Bioactive Compounds Accumulation in Brassica Sprouts Grown Under Altered Gravity Conditions." Journal: International Journal of Molecular Sciences. Volume: 26(23). Page: 11287. DOI: https://doi.org/10.3390/ijms262311287

  • Grudzińska M., Galanty A., Prochownik E., Kołodziejczyk A.M., Paśko P. (2024) "Can Simulated Microgravity and Darkness Conditions Influence the Phytochemical Content and Bioactivity of the Sprouts? - A Preliminary Study on Selected Fabaceae Species." Journal: Plants. Volume: 13(11). Page: 1515. DOI: https://doi.org/10.3390/plants13111515

Other (3rd-party) publications:

  • Calvaruso M., Carmelo M., Minafra L., La Regina V., Torrisi F., Pucci G., Cammarata F.P., Bravatà V., Forte G.I., Russo G. (2021) "Biological and Mechanical Characterization of the Random Positioning Machine (RPM) for Microgravity Simulations". Journal: Life. Volume: 11. Issue: 11. https://doi.org/10.3390/life11111190
  • Borst A.G., van Loon Jack J.W.A. (2009) Technology and Developments for the Random Positioning Machine, RPM. Microgravity Science and Technology. Volume: 21, Issue: 287. https://doi.org/10.1007/s12217-008-9043-2
  • van Loon Jack J.W.A. (2007) "Some history and use of the random positioning machine, RPM, in gravity related research." Advances in Space Research. Volume: 39. Issue: 7. Pages: 1161-1165. ISSN: 0273-1177. DOI: https://doi.org/10.1016/j.asr.2007.02.016.

Offer

Included in the price:

  • Technical support
  • Warranty service (12 months)

Additional paid services:

  • Shipment
  • Installation of the device (if required)
  • Post-warranty service and component replacement
  • Software or hardware upgrades to newer generation (if a newer version is released)
  • Adaptation of compatibility with other laboratory equipment (e.g., incubators, cameras, etc.)
  • Installation of additional sensors on the device or in the laboratory environment for monitoring environmental parameters (e.g., temperature, relative humidity, CO2, CO, noise level, UV level, light intensity, accelerometers)
  • Installation of timers, time switches, and programmable controllers for automatic switching of lighting or device operation (e.g., night pauses) Software for real-time visualization and monitoring of parameters

Contact

For inquiries, please contact at info@aatc.pl