mteh2o

I was wondering if anyone knew how to build snow skis. snow has fallen and I want to fly. anyone got any Ideas or plans.. thanks Todd

e=mc2

I have heard from some senior members of our r/c club that they have tried using skis for flying in snow and weren't very impressed. They have had better success with floats on snow!

I have no personal experience, but I hold a very high opinion of these gentlemen that I heard this from.

e=mc2

yak52

I was flying today and it was lovely. There was snow about 10 inch and very cold. It was little hard to start the engine. You have to connect the skis about 2/3 from the front of the plane or it will fall over.

Snow

Bobby likes 3D

After looking at a Post of skis on a Ugly Stick using 2 sets of main gear and a piece of composite downspout rain-gutter purchased at Home Depot I got this idea for my conventional (tail-wheel) Gear 33% extra 330

Materials Needed are: 1 white plastic house gutter down spout (the one with the elbow on the end), 1 extra elbow (both at Home depot), 1 carbon fiber push/pull linkage tube 36 in., 3/8 square spruce stock 24 in., light ply scrap, 6 small eye hooks (Home depot), 2 plastic nose wheel mounts, 10 servo wood screws, pull pull cable, rubber bands, scrap block of balsa (if you want to make a ski for the tail-wheel)

Assembly: Glue the elbows onto the down spout facing opposite directions, using a band saw cut the downspout in half lengthwise, cutting down the middle of the thiner side of the downspout. Cut off the open end of the elbow and discard. I cute the sides of mine down to save weight, just be sure to leave some length of turned up tip in the front.

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Bobby likes 3D

I cut the 3/8 spruce stock into 10, 2' length pieces and used the the light ply scrap as a laminate on the top or bottom. Using the spruce alone i was concerned that the hole for the carbon fiber rod would weaken it to much, hence the scrap light ply. The gear attach point using a nose-wheel mount was offset forward to aid in stability. The skis articulate at the gear attachment point. They are set at a positive angle of attack reference the fuselage with a cable attaching the rear block and a rubber band attaching the front block as shown.

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Bobby likes 3D

The Skis haven't been tested of yet but i think they will work fine, keep in mind I am in now way an aeronautical engineer this is purely an experimental idea. I have a frozen lake outside my door just calling my name so when I get a chance for a test flight I will post the results.

Hope this idea helps

Bobby

DHG

My Feedback: (7)

Bobby,

Sawing that downspout in half is one of the more clever ideas I've ever seen ... I was all set to recommend something involving 3 to 4 layers of 1/32" ply, laminated in a mold cut from foam. That's how I learned to make them, from the guy who taught me to fly, in Michigan, 32 years ago. The other features of his setup are:

Trike gear mounting, with the CG at 50% to 60% of the way back on the skis (that is, slightly aft, so the front part of the ski is longer than the tail);

Zero degrees incidence (aiplane sits exactly level on the snow);

1.5" to 2.5" rise on the fronts of the skis so they're sure not to dig in;

Hardwood or plywood pylons at main gear strut attach points, to make the skis the same height as a pair of wheels;

Front attachment involves replacing the 5/32" nosewheel strut with a piece of 5/32" brass tube, then soldering twin 3/32" steel wire struts into it. If you do the math, you'll soon notice the 3/32" wire needs to be ground down a little so both struts fit inside the tube. The 3/32" wires run out and down in a "V" shape, one on each side, to engage the fronts of the skis using a simple hole in the plywood (or downspout) and secured with a wheel collar. Finally, solder a 1/16" wire spreader between the struts, just above the attach points, to make the whole affair look sort of like a coat hanger. The spreader bar is essential to keep the nose up and the skis parallel. It's high enough off the snow that it won't drag.

Other tips:

For a .40-.60 size plane (4 to 7 lbs.), the skis need to be at least 2" wide, needn't be over 3" wide, 18" long is plenty.

Steering is via the air rudder.

Lengthwise stiffeners on the top don't help much and will split loose after a while. Ditto for skegs or rails on the bottom.

Try to keep the skis flat and parallel, but if one edge has to be down a little, let it be the inboard edge.

There is nothing cooler than making a 100-yard-long, perfectly straight track down the runway with ONE ski.

Duane Gall
RCPRO

FlyguyXII

My Feedback: (2)

Hey boby cant wait to see her fly!! Looks really cool.

See ya

Rob

Bobby likes 3D

Thanks for the information Duane, After seeing FlyguyXII's stick on homemade skis fly of of my lake, I wanted to get the get behind my Extra again and didn't want to wait for spring. Ive Been flying electric 3D all winter and wanted to get a jump on practice for IMAC this year. Just seeing how well Rob's skis (Laminated ply) worked lit a fire under me. I still haven't test flown yet since I work away from home CA and my Domicile MI, but I'm hoping to get back in the next few weeks. Ill keep ya posted.

Bobby