Sig Riser Questions

[huntermax]

There has been so much good information on the Gentle Lady (which I love) that I thought I would see if there is any good advice for building, changes is building, etc. for the Sig Riser 2 meter.

This is my next project and experiment. I plan to stay with this model in various sizes until I can qualify for LSF IV. I plan to build the 100" version, plus scale up to avout 117". Later I will try it with ailerons and flaps.

This should keep me off the streets for awhile. Help guys!

[Ollie]

Build the first one stock.

Build the second one with bolt on wings to eliminate the parasitic drag of pegs and rubberbands. Build the second one with twice the spar cap crossection on the inner wing panels to double the bending strength of the wing at negligible weight penalty. Gradually taper the trailing edge of all flying surfaces to less than 1/32 inch thickness to reduce drag. the taper of the tail airfoil should start at about 1/3 the chord from the leading edge.

Build the third with the modifications of number two plus the following items. Build the third with contest balsa in the tip wing panels and tail. When you increase the length of the fuselage in the scaled up model, do not increase the fuselage crossection. Do increase the thickness of the side, top and bottom sheeting and round the corners a lot. Use a template to help check for accurately shaping the leading edge of the wing. Extend the top wing sheeting to about 65%of the wing chord to greatly reduce covering sag between the ribs. Put spoilers at 60% of the wing chord back from the leading edge. Make provision for adding up to two pounds of ballast at the CG. Use tapered carbon fiber sparcaps instead of spruce in the wing. Use full front to back width soft balsa shear webs between the carbon spar caps and wrap the spar with kevlar tow before adding the top and bottom wing sheeting. These changes will produce a plane capable of all five LSF levels of achievement.

About 90% of the ingredients for success are piloting and adjusting skills so, practise, practise and more practise.

[ICTHRMLS]

Consider tracing the wing ribs before construction on to a sheet of paper - vellum drafting paper and a 3x0 techincal pen is ideal but anything will work. This will enable you to make new ones in the event of a crash... :( In addition, a xerox copy can be made and the outline is then ironed on to the balsa sheet to facilitate cutting of the ribs. Good luck..............