Cliff Charlesworth Olympia build in Bishop, CA.

[Peter Balcombe]

Sorry Greg, I got the wrong end of the stick as for some reason, I thought you meant the rear skid rather than the main skid
Yes, I fitted a solid skid as I reckoned that this would withstand slightly sideways landings far better than the sprung skid. I have been told by a number of other Olympia builders that the sprung arrangement tends to get ripped off in many less than perfect landings. Also, the full size Glider had silver painted fabric covers on both sides of the entire Springing gap arrangement, so my version doesn't look too different. Certainly, my experience so far with several dozen landings has been no issues at all.
Essentially, I replaced the springing gap with a tapered solid balsa insert a bit narrower than the skid at the bottom and faced this insert with close fitting thin ply side pieces to replicate the fabric covers. By the time I had glassed these in to the fuselage & painted them silver they don't look too bad in my opinion.

[Greg Smith]

Thanks, Peter: seems like a good idea to me, and I'm certainly not about to put scale fidelity above function!

[Greg Smith]

Thanks, Cliff!
This morning I've been sorting out wire/tube sizes. They're slightly different over here. but after all, you only need something that will do the job...
And 'BA' nuts and bolts are interesting, too: sorting them into metric. I'm doubling up the starboard side formers with slightly thicker balsa than the originals: it'll certainly make the nose easier to do with: a bit more gluing area. Ordered an HK tow release (I've used these already, and reckon them to be strong enough).
Not sure what to use for the elevator pushrod: Goldenrod? carbon? Closed loop? Will also be reinforcing the centre formers considerably for wing stresses.

[Peter Balcombe]

Your fuselage looks very nice Greg. Keep up the good work.

I completely agree about wire & screw sizes. We get SWG wire in the UK & changed from BA sizes years ago, so all fixings tend to be metric.
I am pretty sure that I used 6mm solid carbon rod for the elevator pushrod, with small lengths of 2mm threaded end rod bound and epoxied into each end for servo/horn connections via a 2mm metal clevis. You need something which will go between the small rear former gaps. An equivalent tube would probably be just as good. It just needs to be stiff enough to resist bending when compressed along its length.
I also used HK tow releases.
See my build thread update regarding centre section former strengthening in the wing root area. I added ply doublers to the top half of the 3 wing area main formers to stengthen the wing mount area after mine sheared off from the main parts of each former.
I also a replaced the balsa fuselage root centre infill with ply and glassed the 'tween root rib' areas to make sure everything was firmly tied together & have had no further indication of any issues in this area.

[Greg Smith]

Thanks, Peter!
Your advice is well taken. I will use a carbon rod for the elevator, and pull-pull for the rudder. I'm looking forward to that, as I've never done pull-pull before and I like the fiddly-looking nature of it!
I've just started to fit the second half formers and am realizing again how much making up I'll have to do to the profiles get the levels right. That's OK, though: I'm beginning to realize that a contemplative approach is required, at least for me - no end in sight, enjoy the journey. After all, when is it 'finished'? After the test flight? When it's passed on to the grandchild, or unconstituted in a heap of bits on the local slope? Who knows?
Might use some carbon on the centre formers: now there's an anachronism for you...

[Greg Smith]

Peter, I was wondering if you knew roughly how much weight you finally had to add at the front end? I have cast and glued in my lead weight (in the noseblock) and have almost set up the tow release and servo.I've never cast in plaster of paris before: quite exciting. My last attempt at casting lead,was for an Elmira in 1980. I ended up with lead spattered on my face, but was luckily wearing glasses, so I was very careful this time: long-sleeved shirt, leather gloves, full face protection and tongs to hold the tin can! My hollowed out space in the noseblock is bigger than the front former, so I had to add a spacer to the back of the noseblock. Now the nose will be slightly too long!!!

I'm also interested in how you did your modified elevator connection; I've studied the photos but can't quite make it out. Why is it an improvement?

I've decided to build the fin and tailplane before going further so that I can really see what to do at the back end; I think I'll use a supported aluminium tube rather than carbon for the elevator pushrod.

[Peter Balcombe]

Greg,
I don't know exactly how much total nose weight was added, but I did have to add some additional weight inside the fuselage to balance after casting some in the nose block. At a guess, I would think I added at least as much again as was in the nose block.

For the alternative elevator link arrangement, it does make for a much simpler rigging at the field as the tailplane can be simply slotted into place and the single fixing screwed into place, rather than trying to fit the clevis to the pushrod (or in my case, fit the clevis and insert the small screw instead of the clevis pin) as you are also trying to attach the tailplane.

The difference in the arrangement is that the elevator horn is fitted with a short piano wire cross pin in place of the normal clevis attachment hole.
The fuselage pivot was made from 3 pieces of 1/16" (1.5mm) epoxy board epoxied together into a 3/16" wide strip. The centre strip is cut short & a slot is cut down from the top in the outer pieces at the top to allow the elevator horn pin to slide down into the slot when the tailplane is positioned. (Note that the slot needs to be a good fit as any slop will result in elevator linkage slop).
The 3/16" pivot assembly is drilled across at the bottom end for a piano wire pivot pin, fixed to the lower fuselage below the elevator horn, thus allowing equal forward & backwards movement for elevator movement to minimise differential.
Thus with elevator servo in neutral position, the fuselage pivot should be near vertical & the tailplane elevator horn cross wire is easily slid down the slot in the pivot pin as the tailplane is positioned. Insert the tailplane securing screw & the job is done.
Hope this clarifies.

[Greg Smith]

Thanks for the incredibly rapid reply, Peter: I'll study it later!
Best, Greg

[Greg Smith]

I see it: very clever! I'll use it. Something else to make sure of before sheeting the second fuselage side.

[Greg Smith]

Quick question: does Cliff specify brass and dural horns and hinges for authenticity? I was thinking of using circuit board material instead... I have some beautiful material provided by the local Radio Shack fellow, who informed me it has an insulating value of c. 200,000 volts. Might come in useful when I hit those high-tension wires, I suppose.
The hinging looks very time-consuming. I'm wondering if people are tempted to use (sacrilege) ordinary hinging methods for large scale gliders?
Oh, I realized that we used to use balsa pushrods down a fuse, so that's what I'm doing for my rudder; very light and there's plenty of room. Mine is 3/8" squ. with a wire extension for the servo end, and a hard balsa 1/4" by 1/8" short extension to the elevator 'horn'. Sounds too flimsy, I know, but it's actually really strong push/pull!
What a pleasure to build a (for me) conventional structure. The tailplane has taken a couple of days so far. Can't get 1mm ply here, so I'll have to go with .8mm for the elevator TE. Think it will be OK.