Optimize your diesel heater's performance and longevity with this precision-engineered transition adapter.
🛠 The Problem: Backpressure & Carbon Buildup
Standard 3-inch (75mm) flexible ducting is the industry standard for easy installation, but the Autoterm Planar 2D features a smaller 60mm outlet. Attempting to force a 75mm hose directly onto a 60mm outlet creates a bottleneck. This restriction causes backpressure, forcing the combustion chamber to fight against its own airflow.
The consequences of restricted exhaust are well-known in the van-life and marine communities:
Incomplete Combustion: Leads to a "rich" burn and heavy soot production.
ary Component Damage: Carbon deposits accumulate on the glow plug, heat exchanger, and combustion chamber.
Increased Maintenance: More frequent cleaning and shorter overall heater lifespan.
Visible Failure: Black smoke from the exhaust is a clear sign of a struggling unit.
💡 The Solution: The Smooth-Bore Step-Up
This 3D-printable adapter is designed specifically to bridge the gap between the 60mm Autoterm outlet and standard 75mm hardware-store ducting. By expanding the orifice, you eliminate the restriction, allowing the heater to "breathe" freely. This ensures clean combustion, reduces carbon buildup, and maintains the manufacturer's intended maintenance intervals.
Key Engineering Features:
Optimized Internal Geometry: A smooth, continuous internal bore prevents turbulence and ensures seamless airflow transition.
Robust Construction: Featuring a consistent 4mm wall thickness to withstand the mechanical pressure of hose clamps.
Integrated Clamp Grooves: Dual-sided grooves provide a secure, leak-proof seat for clamps on both the heater and the ducting side.
Versatile Design: The 15mm diameter transition is engineered to be a moderate, well-proportioned cone that avoids creating new bottlenecks.
Print-Ready: Optimized for FDM printing; no supports or complex rotations are necessary.
🚐 Applications & Compatibility
Primary Use: Converting Autoterm Planar 2D (60mm) outlets to 75mm / 3" flexible exhaust or intake ducts.
Broad Compatibility: Can be used as a step-up for Webasto, Eberspächer, or other 60mm-outlet diesel heaters.
Ideal For: Campervan builds, RV installations, marine/boat heater circuits, and any DIY diesel heater setup where 75mm ducting is the standard.
Dual-Purpose: Can be used for both intake (air) and exhaust (gas) configurations.
📦 Digital Download Includes
1× STL File: Precision-designed 60mm →→ 75mm adapter.
Specs: 4mm walls, smooth internal transition, pre-oriented for easy printing.
⚠️ Critical Printing & Material Guide
Material Selection is Vital for Safety The material you choose must be dictated by the part of the heater circuit you are modifying.
For Intake (Air) Side: The intake side handles ambient or slightly warmed air. PETG, ASA, or ABS are recommended. Use ASA if the intake is exposed to UV/outdoor elements.
For Exhaust (Gas) Side: WARNING: Exhaust gases reach high temperatures that will melt or deform standard plastics. Nylon (PA) or Polycarbonate (PC) are the ONLY recommended materials for exhaust use.
Strict Prohibitions: NEVER use PLA for any part of a diesel heater circuit. Do not use PETG, ASA, or ABS for exhaust-side applications.
Pro-Tip: If you want a "one-size-fits-all" approach, use Polycarbonate (PC) for its superior thermal resistance.
Recommended Print Settings
Layer Height: 0.2mm
Walls/Perimeters: High wall count for structural strength.
Top/Bottom Layers: 5–6 layers.
Infill: 100% (Solid) to ensure pressure resistance.
Orientation: Print with the 75mm (large) end facing the build plate. No supports required.
Note for Nylon/PC: Ensure filament is thoroughly dried before printing. Use an enclosure and follow manufacturer-specific temperature/adhesion settings to prevent warping.