Nutrient dosing · TR-PMP-001

Peristaltic pump development

Name: FlavoRotor
Brand: FlavoRotor

The custom three-roller pump, its first-order displacement model and the strict distinction between motor command resolution and delivered-volume accuracy.

Markdown JSONRevised 2026-07-26

In brief

The custom three-roller pump, its first-order displacement model and the strict distinction between motor command resolution and delivered-volume accuracy.

CAD view of the FlavoRotor custom three-roller peristaltic pump — **Custom pump architecture.**Original CAD from the supplied pump package. Geometry supports the first-order model; delivery performance requires gravimetric calibration.

Explanation

A three-roller rotor compresses a flexible tube. Advancing the compression moves liquid while the liquid remains inside the replaceable tube. The motor provides a precise command, but only calibration determines the volume that actually exits the tube.

Documented design

Parameter	v2 design value	Classification
Pump type	three-roller peristaltic	design architecture
Tube	3.2 mm ID / 6.4 mm OD silicone	design specification
Nominal channel radius	18 mm	CAD specification
Drive	NEMA 17, 1.8° full step, direct drive	component specification
Command mode	1/16 microstepping	firmware design
Housing	PETG prototype geometry	CAD specification
System channels	four independent pump modules	system design

First-order model

P-1

A_t=\frac{\pi d_i^2}{4}

Nominal undeformed internal tube area.

ExplanationTube area is calculated from its internal diameter.

P-2

V_{\mathrm{rev,ideal}}=A_tL_{\mathrm{eff}}N_e

Ideal displacement per rotor revolution using an effective displaced length Leff and displacement-event count Ne.

ExplanationIdeal volume per turn is tube area multiplied by the effective squeezed length and the number of displacement events.

With d_i = 3.2 mm, L_eff = 25 mm and N_e = 3, the report model gives A_t ≈ 8.04 mm² and V_rev,ideal ≈ 0.603 mL/rev.

P-3

V_{\mathrm{rev,meas}}=\eta_vV_{\mathrm{rev,ideal}}

Measured displacement represented by a fitted volumetric-efficiency term. ηv may depend on speed, pressure, tube and age.

ExplanationThe ideal volume is corrected by an efficiency measured on the real pump.

P-4

Q=V_{\mathrm{rev,meas}}\,n

Mean flow at rotor speed n in

\mathrm{rev\,min^{-1}}

ExplanationFlow equals delivered volume per turn multiplied by turns per minute.

Motor-command increment

P-5

N_{\mu\mathrm{step/rev}}=\frac{360^\circ}{1.8^\circ}\,16=3200

Microstep commands per direct-drive rotor revolution.

ExplanationMotor step angle and microstepping determine how many commands produce one rotor revolution.

P-6

\Delta V_{\mathrm{cmd,nom}}=\frac{0.603\ \mathrm{mL}}{3200}\approx0.188\ \mathrm{\mu L/command}

Nominal geometric displacement assigned to one command.

ExplanationNominal volume per command is the measured volume per revolution divided by commands per revolution.

Why calibration is mandatory

Tube recovery, occlusion, viscosity, suction head, outlet pressure, roller geometry, motor torque, microstep non-linearity and tube wear all alter delivered volume. Peristaltic-pump modelling and published multi-channel systems therefore use physical calibration rather than geometry alone.

Progress classification

The pump geometry and four-channel module are substantial v2 engineering progress. The supplied report documents CAD, component selection and the analytical model. No traceable FlavoRotor gravimetric dataset accompanies the report, so delivered-volume performance remains unclaimed until CR-PMP-001 is published.

FlavoRotor design provenance

The system-specific configuration on this page is traced to the supplied FlavoRotor engineering records.

CAD documentation

Second CAD view showing the roller and tubing path — **Roller and tube path.**Internal CAD record.

Exploded assembly of the FlavoRotor peristaltic pump — **Exploded pump assembly.**Internal CAD record showing serviceable components.

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