I’m starting on my first footy build, a Bill Hagerup Razor, and I decided to go with 1/64" plywood with a 1/8" lite ply frame 1/4" wide at the deck rail. I haven’t added the decking yet, but it’s likely to be 1/16" or 1/20" balsa.
Anyways, what should be a goal weight for an empty footy hull without rudder, keel, etc? Right now I’m sitting at 29 grams. (a hair over 1oz.)
For what its worth, my first boat was also a Razor in 1/16" Balsa with no frames weighed in at exactly 1 oz. The deck in 1/32" ply was 0.375 oz with a plastic hatch cover.
My second build is a scaled US1M design using 1/16" Balsa planks on Balsa frames - subsequently removed. This came out at 0.75 oz for the basic hull shape plus 0.7 oz for the 1/32" ply hull with a solid plank effect hatch or 0.375 oz with the plastic cover.
My advice is not to worry too much about weight. My razor finished up at21.25 oz or 600 grms. It sat a bit low in the water but otherwise performed quite well with standard servos and ply servo mounts.
The scaled US1M - which I’ve named Mistralette - comes in at 17.5 oz or 500 grms. This has HS81 and HS 55 servos and Balsa servo mounts. I wouldn’t say its any faster than the Razor, but it certainly handles better - particularly downwind. It also has less of a tendancy to turn violently into the wind in gusts. I think this is down to the charcteristics of the Razor’s chined hull.
Thanks for the information. I’ll continue onward. It sounds like I’m not far off.
Ideal hull weight is obviously Zero.
But l0oking at the big picture anything under 50g is workable.
My best efforts are around 10g for hull and deck.
10g for hull and deck - wow!
Well my 29g looks like it’s right in the middle of the road. I’ll take that for a first effort.