Xanadrone
Well-Known Member
I’m watching with maximum attention the one- or two-spars debate, as well as other discussions related to the composite-techniques.
So, being in the… napkin-phase
of a microlight-amphibious project - and convinced by Autoreply that carbon-fibre construction is not really horredously expensive -, I wonder if a THREE-spar composite (carbon) wing would be feasible.
I’m trying this approach mostly as a possible lower-price and/or manufacturing time option.
I’m attaching just simple in-a-hurry sketches for the moment, whilst I’m in the (long) process of analyzing for my necessities the technical data of the commonly available carbon-tubes (or better square-tubes I guess) - pullwinded, pulltruded or “technical”-made:
- approx. 4 mp Hershey-bar high wing - no twist, no dihedral
- one-piece wing, with Fowler flaperons attached,
- 5,80 m (19 ft) span, cca. 45 kg/mp specific load for 180 kgs=400 lbs. MTOW,
- AR=8+
P.S. Some preliminary calculations show that at 4 Gs, 2 mm wall-thickness superposed square-tubes, each 30x30 mm (or round-tubes 32 mm diameter) seem to be OK for the main spar of a +4-in. (10-11 cm) max. wing thickness, if “telescoped” at the root in some bigger-section 2m-long central tube(s).
So, being in the… napkin-phase
of a microlight-amphibious project - and convinced by Autoreply that carbon-fibre construction is not really horredously expensive -, I wonder if a THREE-spar composite (carbon) wing would be feasible.I’m trying this approach mostly as a possible lower-price and/or manufacturing time option.
I’m attaching just simple in-a-hurry sketches for the moment, whilst I’m in the (long) process of analyzing for my necessities the technical data of the commonly available carbon-tubes (or better square-tubes I guess) - pullwinded, pulltruded or “technical”-made:
- approx. 4 mp Hershey-bar high wing - no twist, no dihedral
- one-piece wing, with Fowler flaperons attached,
- 5,80 m (19 ft) span, cca. 45 kg/mp specific load for 180 kgs=400 lbs. MTOW,
- AR=8+
P.S. Some preliminary calculations show that at 4 Gs, 2 mm wall-thickness superposed square-tubes, each 30x30 mm (or round-tubes 32 mm diameter) seem to be OK for the main spar of a +4-in. (10-11 cm) max. wing thickness, if “telescoped” at the root in some bigger-section 2m-long central tube(s).
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