Elf (oz847)

About this Plan

Elf. Free flight rubber cabin model from KK. Wingspan 16 in.

The Elf is a reduced size version of the larger 30 in Keil Kraft Ace (oz1344) design.

Update 06/04/2013: Added printwood scan showing all the wing ribs, thanks to Bry.

Update 12/9/2023: Added zipfile of extras (includes a new fully redrawn plan, with all parts), thanks to the Lurker.

Quote: "A cleaned up version of the PDF found on Outerzone, September 2021. Minor tweaks resulting from my build using the plan.

Summary
- The main plan given on an A3 sheet.
- Sub-assemblies broken out to A4 sheets.
- A transcription of the original build notes.
- Asymmetries removed.
- Formers & ribs re-drawn.

I’ve assumed that a plan built model will have a solid nose block so the top & side templates are given for that rather than a set of formers to laminate. There are no gusset profiles.

I had hoped to be able to get everything broken out to A4 sheet so no tiling would be necessary, unfortunately at 16” the wing can’t be made to fit an A4 sheet. You’ve two choices; (a) cut and paste the printout to give a one part plan and build the wing with a single root rib (W1) as originally drawn or, (b) build the wing as standard two part with with two root ribs & join. If you do build the wing in two parts note that the dihedral guide is for the plan as drawn so use it to set only *one* W1 off vertical, the other should be set vertical.

Of the formers that are provided I’ve kept the original designations so that the original build instructions can be used. You should note that F5, the nose plug, is drawn oversize. The dotted line shows the *expected* aperture size.

In keeping with current thinking an alternative, more forward, motor peg position is given, F8 bis. This gives a roughly 50:50 distribution of the motor about the CG. If you move the peg location you may want to put in a vertical spacer at the original F8 position to stabilize the tailplane platform.

The outdoor motor recommendation is taken from the original Keil Kraft plan, the indoor motor is what I use and is good for about 43s from ROG for a model weighing 14g inc. noseweight, but without motor. I found that a 1/16" shim was required to get the downthrust right for indoor use and that's why the noseplug is likely to need 3 laminations of F5."

Direct submission to Outerzone.

For some video of an indoor ROG flight of this model built from the tidied up plan, see https://vimeo.com/861757524 note this link will evaporate sooner or later because of space limitations.

Supplementary file notes

Lurker files zipfile.

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