Convair Model 61 IAE V2500 Powered Updated 3D Print 1:150 Scale

Additional Note: Only the display stand files are provided here as free downloads.

The aircraft model itself is available separately through my Gumroad page https://creativedesigns840.gumroad.com/l/kppht

Or you can visit my main Gumroad page on https://creativedesigns840.gumroad.com

Convair Model 61 — The Twin-Jet That Could Have Challenged the DC-9

Concept Overview — A Twin-Jet Convair Successor

The Model 61 was envisioned as a twin-engine turbofan airliner using the JT8D turbofan series, derived from the Convair 990’s powerplant lineage. In contrast to the four-engine Convair 880 and 990, the Model 61 sought to achieve:

• Lower fuel burn
• Reduced maintenance cost
• Improved dispatch reliability
• Competitive economics against short- to medium-haul aircraft such as the DC-9

The T-tail configuration, inspired directly by the DC-9, positioned the Model 61 as Convair’s true narrow-body market response, optimized for high-cycle regional and trunk-route operations.

This design direction mirrors what Douglas later achieved with the DC-9, and McDonnell Douglas with the MD-80 series — scaling a proven airframe into a long-term product family.

Airframe Geometry — Shortened Convair 880 Lineage

Based on available three-view references and CAD interpretation of Fuselage shortened to ~87.5% of Convair 880 length, Approximate fuselage length: ~34.5 m, Structural weight reduction, at the cost of lower passenger capacity, T-tail layout, requiring careful center-of-gravity and pitch stability balancing

Despite the shorter fuselage, the Model 61 appears longer than the Convair Model 60, due to T-tail geometry and aft horizontal stabilizer placement, extending the effective tail moment arm.

Wing & Aerodynamics — Proven 880M Platform with Modifications

A key design philosophy was reuse of the Convair 880M wing and wingbox, minimizing development risk while retaining Convair’s high-speed cruise aerodynamic DNA.

Wing Data (Inherited & Modified)

• Span: 36.58 m
• Root-Tip Airfoil: NACA 64-0012 - NACA 64-0008

Aerodynamic Adjustments

• Wing sweep and wingtip geometry modified to compensate for:
  • T-tail moment arm changes
  • Modified CG envelope for shortened fuselage mass distribution

Unlike the Convair 880M and 990A, the Model 61 relocates engines to the rear fuselage, similar to the Sud Aviation Caravelle, altering:

• Pitch coupling behavior
• Yaw inertia
• Structural load paths
• Maintenance accessibility

Powerplant — IAE V2500 series

The baseline engine assumption is the V2525-D5, producing approximately:

• 111.2 kN thrust per engine (25,000 lbf)

A later conceptual upgrade suggests a V2528-D5, estimated at:

• 124.55 kN thrust per engine (28,000 lbf)

Performance Gains

• Improved takeoff performance
• Better hot-and-high airport capability
• Increased payload margin
• Improved thrust-to-weight ratio

Estimated Thrust-to-Weight Ratio

Using IAE V2500 engines:

• T/W ≈ 0.25-0.28

A strong value for a 1960s–1970s twin-jet, comparable to DC-9-class performance.

Weight & Fuel Capacity — Downsized but Efficient

Estimated Maximum Takeoff Weight (MTOW)

• Metric: ~60,312.61 kg
• Imperial: ~133,000 lb

Due to fuselage shortening and reduced internal fuel volume, total fuel capacity is lower than the Convair 880 — reinforcing the Model 61’s intended role as a medium-range, high-frequency narrow-body.

Cabin Layout & Passenger Capacity Estimation

The Model 61 retains Convair’s 5-abreast (2+3) seating layout, preserving a comfort advantage over 6-abreast competitors.

Seating Assumptions

• Seat pitch: 33 inches
• Cabin layout: 2+3
• Fuselage reduction: ~5 m shorter than Convair 880

Estimated Passenger Capacity

• ~85–110 passengers, depending on configuration
• Trade-offs include:
  • Lower empty weight
  • Faster turnaround times
  • Improved seat-mile economics

IAE V2500 Era — MD-90 / A320-Class Modernization

To compete with MD-90, MD-95, A320, and later **717* and A220 class, Convair transitions to IAE V2500 engines**.

The 49 m variant reaches structural and efficiency limits, motivating a transition to modern high-bypass turbofans.

Performance

IAE V2500 Era — Transitional Upgrade

Thrust class: ~111.2-124.5 kN

Structural Changes:

• Reinforced wingbox
• Strengthened landing gear
• Increased fuel capacity
• Higher passenger capacity (~120–155 seats)

At 49 m, the IAE V2500 and Convair Model 61 platform approaches its aerodynamic and economic limits.

Pack A — 3D Printing Pack (STL + 3MF)

Get Convair Model 61 IAE powered 3D Printing Pack Here for $14

Includes:

• High-resolution STL of the aircraft
• Included Custom Aircraft Stands
• Clean watertight mesh suitable for resin or FDM printing
• 3MF file for layout reference
• Aerodynamic, smooth loft surfaces just like wind tunnel models
• Ready for slicing (Cura, PrusaSlicer, Bambu Studio, Orca-Slicer)
• Optional: scaled versions (1:150, but can be re-sized as 1:72, 1:144, 1:48, etc.)

Perfect for: Collectors · Modelers · 3D printer hobbyists

Pack B — RC Maker Pack (DXF + 3MF)

Get Convair Model 61 IAE powered RC Maker Pack Here for $19

Includes:

• Full DXF cross-section slices (wing + fuselage) for laser cutting
• Up to ~50 fuselage stations
• Wing rib sections
• Clean orthographic section cuts
• 3MF file for RC layout reference

Perfect for: RC aircraft builders · Laser-cut foam/balsa makers · Workshops

Pack C — Engineering Pack (CAD)

Get Convair Model 61 IAE powered — Engineering CAD Pack Here for $24

Includes:

• Full STEP 214 file (solid bodies + surfaces)
• Full IGES file (solid bodies + surfaces)
• Full CATIA file (solid bodies + surfaces)
• Full Parasolid Binary .X_B (solid bodies + surfaces)

Complete aircraft with precise NURBS lofts Suitable for:

• SolidWorks
• Fusion 360
• CATIA
• Creo
• Siemens NX

Engineering-grade geometry

• Perfect for editing, CFD pre-processing, and derivative design work
• 3MF file for layout reference included

Perfect for: Engineers · Students · Aerospace researchers

Pack D — Merchandise Art Pack (DXF + DWG + PDF)

Get Convair Model 61 IAE powered Merchandise Art Pack Here for $11

Includes:

Clean line-art views:

• 3-side view (top, side, front) + Bonus 1-side view (belly)
• Isometric view
• Provided in DXF + DWG + PDF

PDF in both modern black-over-white diagram as well as negative-white-over-black diagram High resolution, ready for:

• T-shirt designs
• Posters
• Stickers
• Wallpapers
• Classroom material

Perfect for: Artists · Merch stores · Classroom projects · Aviation fans

Pack E — Blender Artist Pack (OBJ + STEP + 3MF + GLB + GLTF)

Get Convair Model 61 IAE powered — Blender Artist Pack Here for $13

Includes:

• OBJ + GLB file exported from CAD
• Ultra-smooth wind-tunnel-grade geometry
• STEP file included for those who want to re-export their own mesh

Ready to import into:

• Blender
• Cinema 4D
• Maya
• ZBrush
• 3MF file for layout reference included

Note: Untextured, raw CAD mesh. Perfect for sculpting, kitbashing, rendering, or custom livery painting.

Perfect for: Blender users · Render artists · Hard-surface kitbashers

Ultimate Pack

Includes EVERYTHING in Packs A–E

• STL + 3MF 3D Print model
• DXF Cross Section Laser Cut RC
• STEP 214 + IGES + CGR Engineering model
• DXF + PDF + DWG Merch Poster
• OBJ + STEP + 3MF + GLB + GLTF Render Artist

What You Can Do With These Packs

Depending on the pack you choose, you can:

• 3D print the aircraft
• Build RC laser-cut models
• Perform CAD or CFD analysis
• Render it in Blender
• Create posters, stickers, and merch
• Study the engineering form

This product line is divided into clear “factory-floor” production tiers for different users: 3D printers, CAD engineers, RC builders, artists, and hobbyists.

See Also Different Aircraft of the Era

• Dassault Mercure
• Vickers VC10
• VFW-614
• Tu-134
• Convair 880
• Convair 900