Cliff Charlesworth Olympia build in Bishop, CA.

[Greg Smith]

Peter, once more thank you for your copious and helpful reply: I am printing out your advice and keeping it by me! That, together with the pictures you have already posted, should see me through. Previously, even on scratch-built projects, I have used instructions along the lines of 'do this, then that...' as in RCM&E, for example.' While this is more secure feeling, it probably is not as rewarding as having to work things out to the degree I have had to with this model.
I suppose it's possible that building a prototype might in some ways be easier, because there are no 'mistakes'. Hmmm.
It is remarkable to me still that I can get such good advice so quickly, and makes me aware of my slow pace (especially compared with other posters). Too many interests. Best.

[Greg Smith]

I'm looking at the wing T.E. We only have 1/16" or 1/32' ply available here, so I'm wondering which I should use. 1/32 is .8mm and 1/16 is 1.5mm according to my calipers. The problem is, of course, that those nicely burned 1mm slots in the ribs are too sloppy or not big enough! I'm thinking I'll have to go with the 1/32, but it's worrying, as it's more flexible than 1mm would be, and the glue will not adhere on both sides of the slot (once the additional balsa is added, that shouldn't matter, though). I'm cursing that the U.S. is still not metric. Did you know that on our maps, the spot heights are in metres, and the contour interval is 40 feet?!

[Peter Balcombe]

Greg,
Don’t worry about 1mm ply as we don’t have it over here either.
I have used 1/32” ply (0.8mm). I am pretty sure that Cliff Charlesworth would have assumed 1/32” and am not sure why he would need to put 1mm on his drawing.

Note that the thin ply is prone to be a bit wavy along its length, so I suggest putting a 1/16” balsa spacer underneath the ply strip between each rib (as per the lower part of the balsa/ply/balsa sandwich as this will maintain the ply at a constant height above the building board (& flat) along its length until after you have glued on the upper balsa strips.
The upper balsa strips will also better secure the TE to the ribs as you go.

We re not fully metric over here & have a mish-mash of old with new (pints, gallons etc.)
Our wood supplies are still in imperial fractions. Some things have gone metric but others have not.

[Barry_Cole]

Our wood supplies are still in imperial fractions. Some things have gone metric but others have not.

I always thought of it as going metric, but with imperial units.



BC

[Greg Smith]

Thanks for the reassurance, Peter: and a very good tip about the 1/16” spacers at the T.E. I’m much happier now. Pity the ribs aren’t cut for the 1/32: this would also leave more wood at the end of the rib.

[Greg Smith]

A couple of questions.
1) Can I build the ailerons separately from the rest of the wing: understanding the need for a good fit, of course.
2) Is the washout necessary completely 'in' the aileron, or is there also a little bit in the main wing itself? The reason I'm asking is that I feel it would be easier for me to treat the aileron as a separate structure and build the washout (only 5mm) into it as I build it. Any reason not to?

Thank you!

[Peter Balcombe]

Greg,
I built both Olympia’s with the aileron as part of the wing & only cut the aileron out once the build was pretty much complete.
The washout goes from inboard end of aileron (or thereabouts) to the tip, so you need to make sure that the tip ribs have required washout angle anyway.
I found it easy enough to build the complete wing, with a 1/4” balsa (or similar) wedge of the required length (point X to tip I think) - this tapering from 5mm to nothing along its length.
Position the wedge at the TE & just build the wing normally.
This will make sure that the correct wing profile is maintained and will also be exactly the same on each wing.

It may well be possible to build the ailerons separately but I have no experience of ever having done this on any plane I have built.

[Greg Smith]

Spars laid out on new extended work bench.

[Greg Smith]

Carbon reinforced spar joins.

[Greg Smith]

Point taken, Peter.
My reason was that since the washout line is completely within the aileron, it would be possible and more manageable, to make the smaller structure of the aileron, but I can see that the wing ribs also need a tiny amount of angle, so not a good idea. I'll follow your method.