Sunday 19 September 2010

19th September 2010 - Wing Struts

As per advice a small amount of dihedral (0.2 degrees) was introduced to both wings. This is to allow some shrinkage in the struts when the top is welded. Then the wing struts were attached to the fuselage and marked to length with the top level with the centres of the bolt holes in the strut attach brackets. The wing struts were then cut to length and the front and rear edges notched to fit between the brackets. Next sections of douglas fir were cut and planed to fit into the struts. These protect against any possibility of compression failure under negative G loads. Two sections of 1/2" x 0.065" tubing were cut to length the fit between the strut attach brackets and reamed out to take a 3/8" bolt to act as bushings at the top of the strut and then bolted into place. The end of the strut was then flattened to fit neatly against the tubing and the dihedral rechecked. With everything set up as required the struts were then tack welded to the bushing. The temporary wing supports were removed leaving the wings mounted via the three bolts which will hold them in flight. Finally it was all dismantled again. Next job is to final weld the top of the struts.


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19th September 2010 - Setting the wing incidence


First today, the fuselage was levelled fore and aft and left to right and chocked in position. Then the wings were bolted into place and the dihedral set to zero as per the plans. All the measuring I'd done http://tailwindbuild.blogspot.com/2009/09/15th-september-2009-rib-rework.html paid off as the front and rear spar spacings exactly matched the fuselage brackets on both sides and the spar attach bolts slid comfortably into place in both the wings. A block was cut to create an exact level between the front and rear spars of the right wing . This wing had both the front and rear spar attach brackets bolted into position so provided the reference for setting the incidence of the left wing. On the left wing the rear spar attach bracket had not been drilled to the spar so the incidence of the left wing could be set precisely the same as the right. This was done and the bracket clamped into position and then drilled through the bushes in the spar and bolted into its final location.

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18th September 2010 - Fuselage back from storage

Last week I set to and got the workshop clean and tidy so today I went and collected the fuselage from storage ready to mate the wings. I had intended to do this with the fuselage directly sitting on the drive and chocked up to get it exactly level so that it would be very solid to work on. However, I realised I was going to have to work underneath and that getting it in and out of the workshop was going to need two people so it seemed sensible to get it back on its wheels ready for starting work tomorrow. It hasn't been on wheels since it was primed and it looks much better than before in its smart white coat of paint.
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