Scale Soaring UK

You tell me this after I have already made the crank Rog? I had the alloy sitting there waiting to be used and it cost me nothing and I doubt that it weighs any more than a carbon version.
By the way, I am sitting this evening reading a copy of Airfoils at Low Speeds written by Selig, Donovan and Fraser. I am checking out the polars and lift diagrams of various sections to make sure I have made the correct choice.
Brian.

The carbon version would be over 40% lighter (size for size) but in real terms you're right this wouldn't amount to much. Maybe drill some lightening holes in your aluminium crank

This morning I finished off the tailplane halves shaping the leading edge and tips and trimming the 1/32 ply root facings. I then spent the rest of the morning covering them with white ‘Oracover’.
I then weighed the original tailplane assembly which came in at 296gm (10.3oz). The new tailplane assembly including joiners and crank were weighed and came in at 162gm (5.6oz) – a saving of 134gm (4.7oz). This saving will mean that I should be able to remove 375gm (13.2oz) from the nose of the model and the whole model will be 509gm (almost 1lb 2oz) lighter overall.
Although I can’t be totally sure of these figures until the model is balanced when complete it is a promising start to the project.
Brian.

Well done Brian, it’s coming along nicely.

That's an excellent result, Brian.

Thanks gents. I have to say that I am finding this whole process very therapeutic.
Brian

After my last post I was at the point of fitting the all moving tail (AMT) mechanism into the fin.
I have not been in the workshop for the last couple of days as October time is harvest time and I have been stocking up my freezers and larder for the winter. However my time was not wasted as while I was lifting potatoes I was also planning in my mind the next few steps in the rebuild. I suddenly realised that if I set up the tailplane in the fuselage now I would have no ability to adjust the tailplane parallel to the wing later on and even the slightest difference tends to show. As the joiner tubes, wiring and retainers are mounted solidly in the fuselage any fine adjustments have to be made at the tail.
So as soon as I get a wet day I will start on the wing construction.
Brian.

A few days of heavy rain has allowed me to leave my other duties and get back into the workshop.
I have decided to rebuild the wings using a fully built up wooden structure as I feel that I can produce much lighter wing panels. The original wings were cut from blue foam and had great big spruce spars let into the surface before being covered with veneer attached with ‘Copydex’. There was also judicious use of glass cloth round about the root spar/joiner area. Together they weigh 2.835kg (6lb 4oz) which seems very heavy.
I have drawn new wing plans on paper using the exact same planform as before. I have also been prepared a kit of parts comprising wing ribs, fully tapered main spars, false leading and trailing edges and joiner tubes ready to start construction.
This afternoon as the rain continued to pour down I made a start on the right hand wing.
Brian.

Brian,
Do you not put sub ribs in the LE D box or do you just not bother drawing them?

Robbie, I don't generally add intermediates in the D box. On this wing the ribs will be at the same distancing all the way to the tip. So the rib spacing you see at the root continues out to the tip. In addition I use 3/32 soft/light balsa sheeting to make the wing more handleable.
Brian.