TriFlex – TPU Triple-Helix Trigger Cone for Mesh E-Drum Pads (V30)

TriFlex is a 3D-printable trigger cone for electronic drum pads with mesh heads and a piezo sensor. Instead of a solid foam cone, it uses three TPU helical spring arms with thin stabilizing membranes. The arms give vertical compliance, the membranes keep it laterally stable.

Video – strike test in a PD-128 BC, a KD-85 and a DIY pad:

WHY

- Substantially reduced hotspot compared with the conventional foam cones I used before

- Excellent sensitivity and ghost-note response

- An alternative to foam cones, which compress and wear over time (see the used vs. new foam photo)

TESTED (V30)

- 12" PD-128 BC with the original two-ply mesh head and a TD-9 module

- KD-85 kick pad and a DIY pad

- Several prints behaved consistently

- Strike testing up to approximately 10,000 hits without failure

Longer durability runs are still in progress – I'll update this page with the results.

DIMENSIONS

- Height: 32 mm (TPU body)

- Base: Ø38 mm

- Top contact: Ø9 mm

- Leave about 3 mm above the cone for a compliant top layer (see Installation)

INSTALLATION

1. The piezo (approx. 27–28 mm) sits on a small centered adhesive pad, metal side down, on the drum plate.

2. TriFlex stands on the ceramic side of the piezo. The open underside is intentional: it lets the piezo flex and is part of what makes the cone sensitive – do not fill it.

3. Put a self-adhesive furniture felt disc on top of the cone as the contact with the mesh head (about 3 mm).

4. Adjust mesh tension and module sensitivity as usual.

PRINT SETTINGS (reference)

Printer: Ender-3 S1, direct drive, 0.4 mm nozzle

Material: TPU 95A (RhinoLab TPU 95A HS)

Layer height: 0.20 mm

Nozzle: 220 °C (first layer 225 °C)

Bed: 35 °C (first layer 40 °C)

Speed: 28 mm/s, outer wall 22 mm/s

Retraction: 0.5 mm at 15 mm/s

Fan: 20–35 % after the first layer

Supports: none – Brim: none

Print time: about 66 min, ~1.4 m of filament

The Cura profile I use is included (TriFlex_Ender3S1_TPU95A.curaprofile).

Tips

- Dry the TPU before printing (about 70 °C for 8 h worked for me) – wet TPU strings a lot.

- Let the bed cool and flex the sheet to remove the part; do not pull it by the arms.

- If the first layer does not stick, a 6 mm brim is fine.

FEEDBACK

I'd love to see your makes: which pad, which module, and how it feels. Every report helps the next revision.

ABOUT THE DESIGN PROCESS

TriFlex is my concept, and every design decision, print and physical test is mine. I directed AI tools to do the CAD modelling, geometry analysis and documentation: I defined the goals and dimensions, judged each prototype on real pads, and decided what to keep, change or reject – revision by revision, from the first solid cone to V30.

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Third-party product names (Roland PD-128 BC, KD-85, TD-9) are used only to describe where the part was tested. TriFlex is an independent project and is not affiliated with, sponsored by, or endorsed by those manufacturers.

Commercial use requires written permission from the author.