Aluminium adapter for the K&S Starter shaft (Archive)

Another archive material in the early years we now publish on to the web.

Most of us RC Heli flyers purchased this wonderful hex shaft starter adapter from K&S Japan, we did too back in 2002. A quick check up and we noticed currently this starter adapter is still in production and available in an enhanced version. Link to K&S starter accessory page.

This K&S starter hex shaft product No.239 consists of the Hex ball point 7mm shaft, Hex shaft joint No.239.2, 10mm one way bearing case No.239.1. Mounting the starter shaft requires a plastic 8mm No.258 spacer to wrap around the starting motoring shaft.

Generally its a good idea to use the spacer, as it allows the starter to wear the spacer in an event of an engine hydro lock. However from as time goes by and the spacer begins to wear out, losing grip and a new replacement is needed. For those who think a spacer is not necessary, we designed and built an aluminum adapter. The ultimate setup.

The screen shot on the left shows the original K&S design, the green piece is the No.258 spacer. The photo on the right shows our design aluminum adapter.

Turning the adapter prototype

Once measure was done, R&D started turning a prototype adapter. This adapter is to screw onto the Sullivan starter (a standard 8mm) motor shaft and secured by setscrew (Not shown on the picture).

Installation of one way bearing case is next

We slightly modified the one way bearing case and now setscrew can be used. Once we have the bearing case inserted, we secured the case by means of tightening the screws and setscrew.

Final – Complete view

This is the end state product view.

  • The aluminum adapter screwed onto the starter shaft and secured by setscrew
  • One way bearing case inserted to adapter and secured by setscrew
  • The rest of follow regular installation of the starter shaft

The entire photo set of development photos can be found here.


Leave a Reply

Your email address will not be published. Required fields are marked *