I'm in the process of adding of adding a set of floats to a Goldberg Senior Falcon. I'm planning on using dural (aluminum) landing gear for both the fore and aft mounts (the current main wheels are using the aft dural mount).

My question is: when using the dural landing gear vs. bent wire how important are the crossmembers and diagonal braces? Are the horizontal crossmembers typically in tension or compression? I want to use as small a gauge crossmember as possible.

Thanks!

shv2sail

The horizontal crossmembers are called spreader bars, although they SHOULD be called anti-spread bars. Their function is served in tension, and they can be quite lightweight. With dual Dural Landing gears, I would wager that you could dispense with them entirely. Put 'em in later if you notice that the floats are dancing over ripples.
With a floater like a SrFalcon, you won't spend any time on the water once you open the throttle anyway.
Save a buck or 20 and get the 3/4" x 1/8" aluminum stock at home depot. Bend it into the appropriate shape and use spreader bars, since it is softer than dural. Lighter, less expensive, and you can bend it to juuuust the right size to ensure the proper incidence angles without a lot of shimming.

Thanks, Jim. I'm using some dural mounts I had laying around the shop, or I'd do the make-it-yourself mount as you suggested...maybe for the next plane!

They're pretty stiff, so I think I'll follow your suggestion and see how they work without the (anti)spreader bars, then if needed, add some tensioning material (probably some light wire or carbon fiber).

Really wish I still lived in central FL so I could join you FFF folks - especially with how cold it is in DC is right now! Still searching for a good float flying site up here - though it looks like I'll have plenty of opportunities to fly off snow this winter.

Thanks again!

Steve

Steve,
If you do decide to add spreaders, one way to do it would be 1/16 wire. Just drill a hole next to where the dural gear bolts to the float tab, run the wire thru, and pop on a (tail)wheel collar. Of course, all the recommended practices like grinding a flat for the setscrew still apply.

Most clever idea I've seen for spreader bars is to use an arrow shafts. Hunting arrow shafts use inserts that allow various "points" to be threaded into them. Turns out this thread is a standard 8-32. You cut the arrow shaft to the right length, epoxy inserts into BOTH ends, then use 8-32 screws to attach them. Bow hunters know what I'm talking about. Next time your in a sporting goods store that sells bow hunting equipment check it out. It's light, stiff, strong, easily adjustable, and removable.

Thanks for the replies, guys. The arrow shaft is a neat idea...we have a fairly new Bass Outdoor World 'Mega' store that has a large bowhunting section...I'll have to check it out!

Thanks again-

shv2sail