Assembly — microfluid pump

Build sequence

1. Print housing halves (resin, 50um layers)
2. Press steel shaft into cam stack, check for wobble
3. Route silicone tube through the channel, leave 40mm tails
4. Close housing, secure with M2x8 screws (4x)
5. Press barb fittings into the tube ends
6. Attach motor to shaft coupler
7. Prime with distilled water, check for leaks

First build notes

The housing halves warped slightly during UV cure. This left a 0.3mm gap at the seam. Sealed with a thin bead of silicone adhesive — not ideal for repeated disassembly.

The barb fittings leak. The tube wall is too thin for the barb geometry — the silicone tears slightly at the barb teeth under repeated compression cycles. Next build will use thicker-wall tubing (2mm ID, 1mm wall instead of 0.5mm).

Lessons learned

• Resin prints need longer post-cure to prevent warping. Try 30 min instead of 15.
• The cam shaft must be dead straight. Even 0.1mm runout causes pulsation.
• Dry-run the pump without fluid first to check cam timing. You can hear when the occlusion pattern is wrong.