Jump to content

Prop for Korda Wakefield


Recommended Posts

Thanks Martin, Yes the plan does have a good detailed drawing of the prop, thank you for that info. However, I am still not sure of the way it works. Looking at the drawing I presume the blade is held by the rear hinged wire bracket, the tension of the wound motor pulls the pin into the hub against the spring, thereby driving the prop. Now what I am not sure of - does the prop stay up in the drive position on the hub purely by centrifugal force and when the motor winds down disengaging the drive pin does the blade then fold? any explanation would be helpful.

Many thanks

Link to comment
Share on other sites

That's how I remember them working Alan, you hold the tip of the blade out at release and when it starts windmilling at the end of the 'power' run the airflow blows the blade back just like it does with an electric glider folding prop. IIRC rather than carving blades, sometimes we used blades laminated from 1/16 balsa and moulded round a jamjar to get the camber. The root would be built up by adding harder balsa to accept the wire pivot.

Link to comment
Share on other sites

Pitch is a geometric function so that should be ok, however they are designed for the relatively harsh startup and higher revs from an electric motor so my concern (other than a lock of blade area) would be the weight of them. Those that I've used on electric soarers are still quite light so might be worth trying as an experiment.

As for shape, in my opinion that would be less important than area.  You might want a longer electric blade to compensate for the lack of area to absorb the power from the motor and extend the run.  One good point is that the blade should have an accurately formed and efficient section compared to a hand carved prop.  At least for my carving standards it wouldlaugh

Edited By Bob Cotsford on 17/08/2020 13:00:05

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...