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Designing ultralight floats

Posted By:
Bill Berson
Homebuilder or Craftsman
106
Posts
19
#1 Posted: 4/12/2011 16:38:35

I think I might design a set of floats for my 200 pound (400 lb gross) airplane. (unfinished)

What float design info is available?

I have the 1930's Flying and Gliding Manuals with plans for the Heath Super Parasol plywood floats. And the plans for metal Pietenpol floats from  Sport Aviation archives.

Do I need anything else to design a set of flat bottom metal floats?

thanks 

Bill



Andy Gelston
Homebuilder or CraftsmanAirVenture Volunteer
2
Posts
0
#2 Posted: 5/2/2011 11:17:03

The Gemini Hummingbird, a twin-engined ultralight, originally had flat bottomed floats that were blow-molded plastic over foam cores.  I still have a set.  They were found to take a run of a couple thousand feet to get airborne.  Replaced with V-hulled floats, the Hummingbird could leap off the water in a couple hundred feet. 

I would recommend V-hulled floats over flat bottomed ones.  They may be a bit heavier and harder to build than the flat bottomed ones, but it will be less work than rebuilding the whole airplane after you get it down out of a tree on the shore.

Andy



Bill Berson
Homebuilder or Craftsman
106
Posts
19
#3 Posted: 5/2/2011 19:09:05

Andy,

That's interesting, but there must more involved in your flat bottom float experience. (size of step maybe?)

All the information I have indicates that flat bottom is better for getting on step. The only reason for not using flat bottom, as far as I know, is rough handling in waves.

Somebody gave me a pair of fiberglass floats yesterday(unknown brand). They are 10 feet long with triple V bottom and weigh 60 lbs each. These fiberglass floats are much too heavy, I still plan to make my own floats with metal, hopefully around 20-30lbs each.

Bill