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Wednesday, January 10, 2018

Quantum F3F

I'm proud and quite happy to say, that finally the Quantum F3F should be alive soon !

It has been a long project since the beginning, project which has nearly died when the initiator and manufacturer just abandonned the design team "in the middle of the river". But after all the effort Dirk Pflug, Gian Marco Occhibove and I put in this project, we just couldn't let it die so we found another manufacturer (ISM), much more serious this time, and resumed the project by revisiting the CAD drawings, doing some changes here and there to help manufacturing, then start milling.

Molds are now finished and the first prototype should be ready beginning of 2018. The time to build it and maiden it, and I will keep you informed and share my first impressions.

The Quantum has been designed only with F3F in mind, starting from an aerodynamic study about optimum turn radius vs plane weight/wind/flight time/Cz/Cx/etc ... 

What has been considered during the design is:

  1. Turn radius versus Wind speed
  2. Turn radius versus plane weight
  3. Turn radius versus initial entry speed
  4. Relative speed/air and Re
  5. Cz in straight line
  6. Cz during the turn
  7. What pourcentage of the time is spent in the turn

From this we could identify and optimize for a certain Cz - Flight Regime, and target the ideal thickness and camber. This allowed us to obtained the necessary requirements to design the section that Dirk then created especially for the Quantum. Wing planform is a pure elliptical lift wing, with a 2.98m winspan and 15.7 aspect ratio. We payed attention to the wing-fuselage and tail-fuselage junctions to reduce the drag with a dedicated root airfoil.

Here are the main data:
  • Wingspan: 2980mm
  • Length: 1465mm
  • Wing area: 55,6 dm²
  • FAI Wing Area: 61,0 dm²
  • Empty Weight: 2,2kg
  • Empty Wing Loading: 39,6 g/dm²
  • Max FAI Flying weight: 4575gr
  • Aspect Ratio: 15,74

The Ballast compartiments in the wings and in the joiner allow to incrementally increase the flying weight up to the max FAI wing loading of 75gr/dm2 without moving the CoG of the plane, so no need to add or remove balance lead in the nose. Also the maximum weight can be achieved without using very expensive tungsten slugs, brass being enough.

I also prepared a simple color scheme proposal that will be available is different color combination (comments are welcome).

You will easily understand that I'm very excited to receive the first prototype and fly it to see how it performs. I'm like a child ... and I have even prepared the 3D printed spacers file to go with the ballast ;)

Ivan Sanda Models will manufacture and sell the Quantum F3F. But please be patient and give us some time to fly the model first and do adjustments if necessary.

F3F season 2018 will be definitively very interresting and challenging for me !

Stay tuned !

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