Cliff Charlesworth Olympia build in Bishop, CA.

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Greg Smith
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Greg Smith » 07 Dec 2017, 04:21

Now I see; I had looked at Peter's pictures and still couldn't be sure. The lower blade has the diagonal, which is the end closest to the fuselage, and when the servo pulls on the actuating 'bellcrank', it moves towards the fuselage to close, while the upper blade moves away from the fuse to close.The blade parts are mislabelled on my laser cut parts. Thanks, guys!

Greg Smith
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Greg Smith » 02 Jan 2018, 21:56

The first wing is going quite well. I overdrilled the holes in the spoiler box, so had to remove the ply doublers and start again. As often, I was schooled in my reaction to this silly mistake by the commentary of David Glen in his superb book 'Spitfire on my Workbench'. No hurry... if you're in the wrong state of mind, leave it alone and do something else. Certain members of this fine site must be much more advanced spirits (no sarcasm there) because they can build quickly: perhaps they make fewer mistakes, as well? Anyway, to save the original spoiler box sides I cut out little squares to receive a new piece of 1/8" ply which I could then drill properly. I'm glad to say that the new fit for the axles is tight, and a little more robust than the originals.

QUESTION: hopefully, the last about the wing build, but I doubt it. I noticed that Cliff says to cover the ribs aft of the ply sheeting with cap strips of 1mm ply, 1/8" wide. I don't think the ply would have any structural purpose: couldn't I just use hard balsa? I don't understand what happens at the TE: do you have to recess the strip into the end of each rib, or am I missing something? Are the aileron ribs covered in a similar way? Please help if possible: I can't really see what's going on in Peter's excellent photos.

I'm eager to clear the bench to build a Libelle, received for Christmas 2016, so that's my motivation to get this first wing finished. The prospect of starting the other one does not, I must confess, fill me with delight. I like building, but the number of repetitive tasks involved does not suit my temperament. Since this is not a site for online therapy, I'll say no more unless asked...

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Peter Balcombe
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Peter Balcombe » 02 Jan 2018, 23:14

Greg,
I suggest that you check the plan again!
The plan calls for 1mm ply for the TE core, sandwiched between two layers of 1/16” balsa, sanded to follow the rib profile (I.e. down to just over 1mm thick at TE).
There is a note on the plan (between ribs 11A & 13 in the D box area) which says “From rear of aux spar to front false L/edge is covered in 0.5mm ply in brake area, outboard of rib 13 .....”.

Whilst the note specifically refers to the brake area, it means that the whole of the D box is sheeted in 1/64” (0.4mm) ply back to the rear of the main spar, plus the area aft of the D box around the brake box back to the aux spar.
In addition, I used 0.4mm ply to skin all other solid wooden surfaces on each wing and aileron, I.e the aux spar plus rear extensions for aileron hinge shrouds, the aileron upper & lower surface woodwork, the upper & lower surfaces of TE, plus top & bottom rib cap strips.
This should then essentially give all woodwork aft of the D box a 0.4mm ply skin. This increases the TE thickness to just over 1.8mm.
I fitted my Aux spar, TE etc. skins as long strips wide enough to cover the nderlying wood (plus a little bit) & then added 3/32” - 1/8” wide cap strips over each rib edge, cut from a longer length & trimmed to fit in each gap.
Once the joints have had a light sanding to get flush, you will have a smooth outer skin to cover.
Hope this helps clarify things.
Peter

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RobbieB
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by RobbieB » 03 Jan 2018, 00:02

Greg,

Peter has given a perfect explanation regarding your confusion but sometines a picture paints a thousand words (or something like that, anyway).

So, if you look at the attached drawing taken from Cliff's book, the top most picture shows what Peter has described - the only difference being Ciff has used 0.8mm ply instead of 1.0mm ply with the in-fill balsa top and bottom between the ribs.
IMG.pdf
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Greg Smith
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Greg Smith » 19 Jan 2018, 03:30

Cliff's instructions on the plan.
Attachments
P1040029.JPG

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Peter Balcombe
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Peter Balcombe » 19 Jan 2018, 09:53

Hi Greg,
Yes that is the note I meant.
The note effectively says to skin the area between R9 & R13 back to the auxiliary spar (i.e. cover from false LE back to the rear of the brake box area), plus cover between false LE and rear of main spar inboard & outboard of that .

So.... what this means is that you skin the whole wing top & bottom between rear of main spar and the false LE (D box), plus the areas top & bottom around the brake boxes.
There is then an additional note near R4 saying to also skin the areas inboard of the angled shoulder spar and everything between ribs 1 & 2.
In addition to that, there is a note rear of the ailerons saying to fit 0.5mm strips for aileron shrouds & hinge spar cap strips.
If you look at the hinge point section (just under rib 14 section), you will see that the drawing shows a skin on both the rib and aileron - so this confirms that there should be main rib capping, aileron rib capping as well as TE capping.

I fitted the D box skins in several sections (previously having fitted rib top/bottom doublers where I planned to have a skin join), scarfing the skin edges for about 1/4” to get a stronger joint. (Do the top skins first whilst the wing is still jigged for tip washout).
I probably cut the ailerons from the wing at this point as the D box skins would have made the wing rigid.
I then fitted the sections aft of the main spar at root and in brake box area.
I then fitted spanwise spar caps, aileron shroud strips, TE caps etc.
I then finished off with all rib caps.
So, by this point, you should have all surface wood skinned.
I forgot to say that the LE strip is only glued on after the D box skins have been sanded back flush to the false LE strip, then the LE is planed/sanded down flush to the skins & shaped to nose profile by eye.

I must say, as Robbie has reminded me, that happening to already have Cliff Charlesworth’s book which contains a chapter on building the Olympia, did help a lot at certain points as the photographs filled in/clarified some of the detail not evident from the plan.
Peter

Greg Smith
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Greg Smith » 19 Jan 2018, 16:27

Hello Peter! A most comprehensive set of instructions: thank you. I had a long post yesterday which disappeared when I tried to add another picture, so at that point I gave up! I’ll call later (probably about 9pm your time) . It’s very easy and there’s no urgency, so please don’t work anything around such a call!
The wing is off the board and seems rigid: it will go back on for sheeting. Quite a moment, but plenty of work to do on it still.

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Peter Balcombe
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Peter Balcombe » 19 Jan 2018, 16:58

Hi Greg,
I gather that the forum was being worked on at times yesterday, so that probably caused your problem as it also happened to me yesterday.
If you tried again then it would probably work ok.
I will be in this evening, so will be ready for your call (3rd time lucky hopefully).
Peter

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Peter Balcombe
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Peter Balcombe » 19 Jan 2018, 22:30

Greg,
Nice to talk to you.
Check out my Cliff Charlesworth Oly 2b Update build thread page 2.
The 10th Dec 2015 post shows the pretty well complete wings & aileron structures prior to covering and shows the 0.4mm TE skins & rib caps.

The modified brake parts are shown in posts of 21st & 23rd Dec 2015.
The angled blade end is on the wing underside at the root end, moving downwards and towards the root as it opens.
The angled end allows the blade to always clear the end of the box as it comes out. (The tipside upper surface is scolloped to achieve the same effect as this comes up/out and towards the tip).
The actuating brake arm is at the root end as in the brake assembly photos should have the attachment point on the lower side, so is just below and outboard of the arm pivot when the brake is closed, moving further below the pivot as the attachment point is pulled towards the root to open the brakes.
This ties up with my previous expectation that my brake servos pull the brake open & push it shut.
As you say, if you pull the brake open too far, then the brake arm goes over centre & locks open! Thus you need to make sure you set the travel to just less than fully open to avoid any lock up.

I have just had a thought :o
You need to make a left hand and right handed brake assembly as the brake blade should be on the same front/rear side for the tops & bottoms.
I will check mine tomorrow!!

I will also check the servo positions tomorrow, but I may be able to check in the meantime via the build thread/update photos.
Peter

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Peter Balcombe
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Re: Cliff Charlesworth Olympia build in Bishop, CA.

Post by Peter Balcombe » 19 Jan 2018, 22:57

Greg,
Aileron servo was fitted in rib bay in front of main spar, forward of the aileron horn, with access via taped on hatch in wing underside. I think it was essentially fitted where Cliff Charlesworth had his aileron pushrod bellcrank.
There is a photo of the installed 9g servo in the archived build thread.
It was a tight fit, but the servo just fitted under the skinning & no servo arm is visible as in the original plan.
You may have difficulty getting a wing servo into the rib spacing, but I suppose you could always put in a dummy rib to widen the appropriate bay.

The brake servo was fitted just behind the main spar under the root end angled skins so that it was out of sight.
This was again installed in a single rib bay on a ply plate - all accessible via a taped on hatch cover on the wing underside.
Servo horn is ok on the lower side as this is same side as the brake actuation point.
I will check exactly where it was tomorrow.
Peter

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