ULTRALIGHT F-14 TOMCAT

48" span Β· balsa disc-on-stick Β· FPV ready Β· target π“…‚ 249g (cheeky optimism included)

sub-250g Moonshot
Onshape ← SolidWorks rewiring
FPV + variable sweep

πŸ”± the golds of this build

why we're doing this (retrain, redesign, renegade)
retrain CAD muscle memory cloud-native Onshape disc-on-stick fuselage

After 20 years of SolidWorks, this project is the ultimate flight simulator for my design instincts. Onshape forces a new mindset: no local files, no β€œPack and Go” β€” just parametric freedom and real-time collaboration. Every disc is a unique part, every sketch a weapon against the status quo.

the 250g dare
Scale 1/4.8. 48" long. Balsa discs, carbon tube spar, micro FPV gear. Realistic target? 360-430g. But aiming for 249g is the kind of lunacy that breeds innovation β€” minimal covering, 2S battery, hand launch, no landing gear.
First disc modeled
23 unique stations
Onshape assembly mates
Laser / hand-cut balsa
FPV pod + wing sweep
sub-250g maiden

✈️ Onshape immersion · retraining the right hand

from SolidWorks reflexes to cloud-native muscle memory

SolidWorks reflexes: Ctrl+Q rebuild, selecting plane first, local assemblies, β€œfeature tree anxiety”.
Onshape discoveries:

  • Sketch tool β†’ then plane (the subtle holy grail)
  • D key for instant dimensions
  • Negative mate distances = reverse direction (who needs a flip button?)
  • Every tab is a Part Studio β€” perfect for 24 unique discs
  • Assembly linear pattern? skipped. We need individual BOM items for wood cutting.
breakthrough moment
"I clicked the Right plane, pressed sketch, and saw no toolbar..." β†’ then discovered the floating dialog + view cube. Now each disc (Disk_00 to Disk_23) has its own clean part studio, and the main spar is a 6mm carbon tube. The assembly grows like a real airframe: one concentric mate at a time.
parametric discs loft-ready philosophy weight shaving mentality

πŸ“ fuselage architecture Β· disc-on-stick metaphysics

the bent axis, offsets, and why every disc tells a story

The F-14 is not a tube β€” it's a lifting body with a broken axis. To capture that in balsa, every station disc carries an offset (Y coordinate) relative to a straight 6mm carbon dowel. The dowel runs from nose tip (0,0) to tailpipe (1150mm, -80mm). Positive offsets create the cockpit hump; negative offsets produce the rear droop.

🎯 Forward oval stations

X = 0mm β†’ 500mm: true elliptical discs. Max height @ 300mm (186mm tall) and max width @ 400mm (165mm wide). These give the signature Tomcat shoulder/canopy presence.

ellipse width/height

🧱 Main body rectangles

X = 600mm β†’ 1150mm: simplified rectangular formers. This matches the flat "pancake" deck between engine nacelles. Round the edges later with sandpaper β€” structural simplicity first, aerodynamics second.

width x height
ultralight iteration loop β€” each disc is individually modeled (Disk_00 to Disk_23) so you can request "cut me Disk_17" from your laser guy. Thickness varies from 3mm (nose) down to 1.5mm (tail). Lightening holes optional but encouraged.

⚑ sub-250g FPV · the cheeky engineering manifesto

realistic vs. absurd, and why we push anyway

249g at 48" length? That's lighter than many micro quads. Realistic breakdown:

  • 6mm carbon tube spar: β‰ˆ12g
  • All balsa discs + stringers: β‰ˆ75–90g (porous light balsa)
  • Covering (doculam 20Β΅m): ~18g
  • Dual 12mm brushless + props: ~40g
  • FPV cam + 2S 650mAh: ~42g
  • Servos (2x micro) + linkage: ~18g
optimistic total β‰ˆ215-245g real world β‰ˆ360g
FPV cockpit view
The forward discs are sized to fit a micro AIO camera (nano whoop style) inside the windscreen area. The spine will house a minimal video Tx. Wing sweep is a stretch goal β€” but for now, fixed wings + low weight = epic thermal ride.

🧩 BOM & iteration cockpit

digital inventory, next steps, and the beauty of iteration

πŸ“¦ current digital inventory

  •  Main_Spar (6mm carbon tube, 1150mm)
  •  Disk_00 – Disk_23 (each unique dimensions)
  •  Assembly: concentric mates + negative distances
  •  Next: motor mount former, wing glove fairings

πŸ”„ iteration superpowers

Because every disc is its own part studio, scaling or reshaping a single station doesn't break the rest. The Onshape version tree keeps track of every "what if" β€” try 2mm thinner at station 400, see the weight difference instantly. This is the agile way to build ultralight balsa warbirds.

Disk_01 modeled & mated full 24 discs in assembly 1:1 print templates balsa cutting party

πŸ’¬ BUILD PHILOSOPHY Β· WHY WE TRY

cheeky, relentless, and statistically absurd
β€œA 48" balsa Tomcat under 250g is statistically absurd β€” and exactly the reason you do it. The process rewires your CAD brain, forces creative weight shaving, and at the end, you either have a miracle or a spectacular crash. Both are learning.”
20yr SolidWorks β†’ Onshape convert
every gram counts
FPV or die trying

PROJECT SWINGTEC Β· F-14 Tomcat Ultralight

Onshape native Β· disc-on-stick fuselage Β· sub-250g daredevil