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Olympia 2b 1/3 scale**

Let us all watch your new project progress.
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Trevor
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Joined: 19 Jul 2016, 16:29
Location: Hampshire
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Re: Olympia 2b 1/3 scale

Post by Trevor »

Very neat. How did you cut that rebate?
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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Olympia 2b 1/3 scale

Post by Peter Balcombe »

Trevor,
Very carefully ;)
As I knew that there was a small step between the top two layers, I started by carefully removing the skin at one end, starting from the top until I had exposed the start of the 2nd layer.
It was then a case of carefully working along the joint line with a sharp blade, removing the material bit by bit.
Luckily, I had attached the skin using white wood glue, so easier to ease away from the top piece as I worked my way around
Edges tidied up with a square needle file to complete.
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Peter Balcombe
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Location: Clevedon, North Somerset, U.K.

Re: Olympia 2b 1/3 scale

Post by Peter Balcombe »

Progress is looking good on the scale airbrake front :)
After having assembled the brake arm yokes using a 3D printed jig (as previously shown) the arms have now been fitted with 3/32” blade hinge bearing tubes & the central cross tube length trimmed to fit inside the brake box.

The 1st pair of blade boxes have also been made up as laser cut sides glued either side of a 1/4” Sq. Balsa spacer. The laser marked pivot hole locations have had 3D printed carbon doublers glued on the outside & the holes in these opened out to take the 16SWG hinge pins.

Pleased to say that the blades appear to move freely when assembled into the arms, including when the centre pivots are located in the laser cut brake box side pieces.
The scale arrangement increases the overall brake box opening to 25.4mm in order to accommodate the staggered blades. Each blade cap is 13mm wide & an extra brake area skin support sub spar will be added top & bottom to support the staggered openings.
Next step is to make up a dummy brake box to provide a more rigid mount for testing prior to modifying the wings to accept the revised brake arrangement.
Brake assembly parts
Brake assembly parts
3A5EA4C5-F5AA-44F3-B1B7-B9356CF11248.jpeg
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Upper surface view
Upper surface view
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VinceC
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Re: Olympia 2b 1/3 scale

Post by VinceC »

Nice to see the endeavour for True Scale
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Cliff Evans
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Joined: 29 Dec 2019, 15:13
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Re: Olympia 2b 1/3 scale

Post by Cliff Evans »

Peter has asked my to share some video with you.

all.


https://lasercutsailplanes.co.uk
https://patteaklegliders.co.uk
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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Olympia 2b 1/3 scale

Post by Peter Balcombe »

Thanks Cliff.
Note that the brake unit has been fitted in a recycled test box (cut down from recent ASK13 brake build) but having the same internal dimensions as the yet to be modified wing structure.
Essentially, I will move the rear brake aperture sub spars rearwards to 25.4mm behind the existing front ones & fit revised brake box sides (main pivot holes are closer together) on the inside faces of these after removing the unwanted rib sections in the brake box area.
I will also fit 2 additional brake box sub spars (1 upper & 1 lower) to provide a rear skin support for the upper blade & a forward support for the lower rearward staggered blade. (Note that the 2nd of these must only be fitted after the blade unit has been installed & checked as you will otherwise not be able to get the blade unit into the box).
I will also tweak the brake actuation pushrod route to reach the crank on the rear blade, rather than effectively the front blade location - which is where the default blades are located.
The scale blades have 1/4” solid balsa perimeters/0.4mm ply faces, so the blade tops should be able to be readily sanded down to the wing profile before adding the blade caps as usual.

The 1st video clip shows the upper box area closed with balsa to show just the blade opening, whereas the 2nd clip, shows the completely open lower side of the box to allow the blade unit to be withdrawn after testing through the lower aperture after pushing out the two main pivot dowels. Once the extra lower sub spar is fitted, the blade assembly is ‘locked in’.
(On the full size, the blades are individually bolted to the brake arm yokes, so are easily removable).
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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Olympia 2b 1/3 scale

Post by Peter Balcombe »

Back to the fuselage briefly after the initial assembly of the tail feathers showed the elevator being a rather snug fit against the base of the fin :o
It turns out that the 2 other U.K. builds have had the same issue, so after a check with Jilles, the fix is to move the tailplane forward by 8mm.
Jilles will look at this shortly, but in the shorter term, my fix is to move the front sub-former on each of the fuselage tailplane mounts (F17A & F19A) forward 8mm, make the captive nut plates 8mm longer & fit the captive nuts/move the tailplane seat holes forward by 8mm.

The revised arrangement now puts the tailplane & elevator in the centre of the tailplane seat, with adequate space at each end. :)
Original elevator/F22 gap
Original elevator/F22 gap
Revised elevator gap
Revised elevator gap
New holes in tailplane seat (B2)
New holes in tailplane seat (B2)
Reduced forward gap
Reduced forward gap
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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Olympia 2b 1/3 scale

Post by Peter Balcombe »

Having tried to get hold of some 8x3mm brass angle, I have given up waiting & bent up some 0.8mm brass sheet today to make the elevator horn parts.
An hour later, I had the elevator horn soldered up & epoxied into the slot in rear of the elevator, capped with the 1.6mm ply EP3 piece.
The pics below show the installed horn, plus the fuselage linkage once the tailplane has been fitted, although the temporary crank pivot screw will be changed to a 3mm brass pin before the fuselage skinning is completed.
C74D02A4-AE44-463A-BDA0-6C40E4CBE8E3.jpeg
36E339AF-1BA7-4D58-B7F7-A0D5EF8CCB44.jpeg
227E8821-03C3-437C-9D67-718B2F16C602.jpeg
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Cliff Evans
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Re: Olympia 2b 1/3 scale

Post by Cliff Evans »

Another video from Peter.


https://lasercutsailplanes.co.uk
https://patteaklegliders.co.uk
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VinceC
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Re: Olympia 2b 1/3 scale

Post by VinceC »

Smoooooooth
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