ATK301: Extension Spring 31.8

Extension Spring Length 31.8, Diameter 9.5, Wire diam 1.42, Max Len 42.28, Initial Tension 10.5N, Tension 6.98N

  • Manufacturer: Various
  • Product ID: AM 3310 (Flexospring version)

A 31.8mm long extension spring used in the Spitfire flight stick for the roll spring.

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Indicative Pricing With Allowance for P&P

Springs are probably the most difficult and expensive things to source. This is a stock spring available from many different manufacturers (see below on what aspects are critical) and although they are not expensive you'll probably get hit hard for P&P.



Although these are commodity items you may struggle to find an exact duplicate unless you buy from flexospring. If you want to vary any of these dimensions these are the consequences.

  • Length 31.8mm - Do not go any longer. You could maybe go shorter by 1 - 2 mm
  • Diameter 9.5mm - Do not go any wider. You could go narrower by 0.5mm
  • Wire diameter 1.42mm - Not so critical but if massively affects the tension
  • Max length 42.28mm - Longer is fine, shorter is less fine as you'll overstretch it but you may well get away with that on the few occasions you go max roll.
  • Tension 6.98Newtons per mm - Any less and the roll action will feel very week. Any more and you'll stress the design more than I have tested it to. If you're feeling brave try a stronger one