This repository contains all design files, firmware, and documentation for a low-cost, modular, and solvent-resistant fraction collector designed for use in automated flow chemistry applications.
Developed to address the limitations of commercial and open-source fraction collectors, especially in handling organic solvents. This system integrates seamlessly with flow reactors for unattended, reproducible fraction collection. Features include:
- Compatibility with common organic solvents (e.g. Tetrahydrofuran, Tolyene, Acetone, Chloroform, Ethyl Acetate, Isopropanol)
- Programmable 3-axis benchtop CNC platform for flexible configurations
- Drop-counting and real-time volume feedback for accurate collection
- Python-based control interface for full automation
- Compact design suitable for chemistry fume hoods
- Mininimal number of components and easy to assemble
- Total build cost: approximately $1,000 USD
The BoM to construct the fraction collector is shown below.
| Item | Manufacturer | Part No. | Qty | Specifications | Unit Cost (USD) | Notes |
|---|---|---|---|---|---|---|
| CNC Router | Genmitsu | 3018-PROVer V2 | 1 | 425 × 352 × 300 mm | $228.65 | Main platform |
| Selector Valve | Runze Fluid | QHF-SV04M-B-X-U-T10-K1.2-C | 1 | 10 Port or 6 Port | $414.00 | Switching between waste and collection |
| Drop Counter | Vernier® | GDX-DC | 1 | Go Direct® | $206.00 | For drop counting |
| Fixture | N/A | N/A | 1 | Custom 3D-Printed | $2.00 (est.) | For integrating modules |
| Tubing | IDEX | 1502 | ≥5 ft | 1/16″ OD × 0.030″ ID, PFA | $28.45 | Tubing |
| Flangeless Nut | IDEX | P-245 | ≥5 | 1/4-28, PFA | $3.36 each | Tubing connector |
| Ferrule | IDEX | P-200N | ≥5 | 1/4-28 for 1/16″ OD, ETFE | $1.79 each | Tubing connector |
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CNC Platform Setup (1-2 hours)
- Assemble CNC frame per manufacturer instructions.
- Mount custom vial tray or holder onto the platform.
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Selector Valve Integration (30 min)
- Wire the connectors following the above wiring guideline.
- Secure the selector valve on the 3D-printed fixture and the CNC tool head.
- Route the inlet, waste, and collection lines through chemically resistant tubing and nuts.
-
Drop Counter Installation (30 min)
- Secure the drop counter on the 3D-printed fixture.
- Calibrate sensor and tubing height to detect single droplets accurately.
- The fraction collector is fully controlled via a Python interface using the code in the repository.