| [quote=Greyhead]Making serrated rib tapes for fabric-covered wings can be a problem but this simple tool can at least speed up the process even if it still remains a mind-numbing job. In essence it consists of a hacksaw blade fitted to a length of pine, the rib tape material is trapped against the blade and torn into strips.
*** That is a great tip which I will certainly be trying on my next model,as you point out they are very distinctive when the model is in flight.
It is interesting to note that rib tape serrations vary on world war 1 type aeroplanes to those produced from 1930 onwards,the early fabric workers would cut the fabric to width and then draw the weave of the fabric with their hands outwards,this was called 'Fraying' then the authorities developed 'Pinking' or pinked edges to the fabric,this was arrived at by cutting the fabric with specially cut shears which gave a serrated edge,the idea by the way is not just cosmetic as it is done this way should the fabric lift under the slipstream effect,it was found out by tests in wind tunnels that serrations added to the fabric was the best safeguard against this happening.
The well known case of the prototype Westland Lysander shedding its fabric in flight was caused by a combination of the fabric billowing and a lack of any stringing to the fabric,the pilot put the aircraft down safely desopite this traumatic experience ! the rib tapes are sewn through the wings with a long needle and beeswax coated thread,a long and tedious job,the knots are then locked at each rib position to hold the fabric taught.
__________________ 'And there I was oil on my goggles from a broken pipe,then I looked at the altimeter,all I could see was the makers name !' www.wonwinglo.scale-models.net/ |