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-   -   Cheap and Easy Snow Skis (https://www.wattflyer.com/forums/showthread.php?t=69125)

earthsciteach 12-26-2012 04:45 PM

Cheap and Easy Snow Skis
5 Attachment(s)
I have been thinking about making snow skis for my HZ Super Cub for a couple of winters, but didn't get around to it until today. These skis are simple to make and can be built from scraps that many RC's have laying around.

Coroplast (whatever thickness you have)
scrap of ABS plastic
4 small washers
Gorilla Glue
Tools:Sharp razor blades or Xacto

I am not including any dimensions as you should determine the appropriate size needed for your particular airplane. By "determine," I mean take your best guess. But, there is a ruler in a couple of shots, so you can get an idea of the size that I "determined" to be correct.

Main Gear
Trace out a snow ski shape of your SWAG determined length and width onto a piece of coroplast and cut out with a razor blade. I used a lighter to heat up the front portion of the skis to give it that upturn. I think the snow and skim border guys call it "rocker." Crap! That reminds me-I have a "fat boy's" skim board blank that I designed and need to glass. If you see a pudgy, pasty white, 40 something year old skimming the wash along the Delaware/VA/Outer Banks coast next summer, come say, 'Hi!'


Next, draw attachment brackets that will affix the snow ski to the axle and cut out. I attached small washers to the side of each bracket that face the wheel for reinforcement. If your axle is short (like mine) you may have to do some modifying to get everything to fit. You'll figure that out if you run into that problem!


Next, cut out a portion of the flute in the top side of the ski so the attachment brackets recess into the coro. Use Gorilla Glue to hold them in place. In my experience, hot glue is pretty much useless on coro. I used GG because it foams and contacts more surface area than other adhesives. I inserted my attachment brackets so that they angled toward each other. The GG will have enough give to allow the wheels to slide into place.


Once cured, attach to your landing gear axle.

Finally, the tail wheel ski is made from a small scrap of ABS plastic that I used for vacuum forming my own Cub Cowlings. (FYI-its a cool idea, worked, but for the cost, just buy a new cowl when needed. Besides, it looks like HZ has stepped up their game. The cowls are now made from a more durable plastic.) You can use whatever material you have laying around. Come up short? Just scour the house for anything that will work - old spray can tops, abused kids' toys, whatever!

Cut the ABS (or whatever) into a ski shape. I got fancy with this one. Then, I simply attached a small scrap of coro to the ski. I used a fair amount of CA and doused with kicker. Worked out well. I heated a scrap of control rod to drill the hole for the tail wheel wire.


Its snowing right now, so I'll be able to test her out in a little bit! :D

xmech2k 12-26-2012 05:09 PM

Hi Teach! Cool idea! Can I throw out a suggestion for your Cub's safety, though?I see on most full scale planes have some sort of device to keep the skis at a desirable angle when in-flight. Check out this pic:

Cub on skis

I think they have bungees on the front, and a rope or cable on the back. I think once airborne, the bungees pull the front of the ski up, the cable at the back controls how far up it will go. Without them, who knows where the wind will spin them? Of course, maybe on our little planes, the weight will be enough. Just a thought.

Good luck ! Looks like fun. The only skis I can try here are water skis!

earthsciteach 12-26-2012 05:57 PM

Thanks for the advice! The front skis will be fine. even if they get way out of whack in either direction, they will self-correct on touch-down. The tail wheel is another story. I had played around with the idea of attaching a rubber band from the nose of the ski to the tail wheel wire. Your seconding of that concern is enough to make me go ahead and do it.

It snowing like crazy right now! I'm tempted to go try it out!

earthsciteach 12-26-2012 06:47 PM

The skis work great! I was very surprised by how well it steered. I had thought of putting a small "keel" on the tail ski, but it is not necessary.

I had hoped to fly it, but the wind is really howling right now. I found the shelter of small outbuilding to taxi around out of the wind. Once confident, I taxied out and pointed it into the wind. The snow is really wet and grabs right now, so when I hit a dip on the uneven ground, the skis would dig in. As long as it was moving, she skimmed over the snow nicely. I decided to try a short hop. Dropped flaperons to 1/2 down, throttled up into the wind and she was off like nothing! I cut throttle and made a nice landing. Then, a BIG gust of wind came up! It picked the Cub up (I had full up elevator to pin the tail down) about 5 feet up and back toward me! I applied throttle and dropped elevator at about the same time the gust lessened. The Cub was nose down with no forward momentum, into the wind. The end result was like a big hand smacking the Cub to the ground. Ooph! One attachment bracket broke loose of the ski, but no other damage. Easy fix!

Overall, I'm quite happy with my "free" snow skis! They actually performed better than I had hoped.

Now, the snow is changing to sleet, then freezing rain. That'll put a nice crust on the snow. Time to take out the Wing Surfer for belly skidding fun!

xmech2k 12-26-2012 07:57 PM

Sounds like quite an adventure!

earthsciteach 12-26-2012 08:05 PM

Pretty entertaining for a simple taxi test! I did add a rubber band to the tail ski. It keeps the nose of the ski up nicely.

dgjessing 12-27-2012 12:03 AM

Cool! That blizzard condition taxi test report is great :)

For better or worse, mine are going to be a bit more involved. As it turns out, several of my planes have the exact same wheel base dimension, so I'm making a set of skis that can be swapped between them. The skis are bent walnut (ukulele construction scrap) with plywood pieces that allow them to be attached to the wheels with rubber bands:


Next, I'm going to make a wire spring thingie attached to the rear of both skis that comes together at a spot on the underside of the fuselage, attached with a spot of velcro. Unsprung, the skis will be parallel to the wing, but the spring will allow them to flex up a bit so the tail drager plane(s) can sit on the ground with the tail down. Then I need to work out a little ski for the tail skid...

Flight test Friday, with any luck :D

xmech2k 12-27-2012 01:44 AM

Just out of curiosity, did you guys catch the episode of Ice Pilots where they pull out the old snow skis for the DC-3?! I've seen a DC-3 on floats, but never skis before.

earthsciteach 12-27-2012 02:23 PM

DC-3 on floats? :eek:
Missed the episode with the skis. I bet they looked like a toboggan built for 20!

dgjessing-Those look legit! Please post up your flight test.

earthsciteach 12-27-2012 02:29 PM

1 Attachment(s)

This is an impressive photo. Thanks for mentioning, xmech2k. Must be quite a sight in person!

xmech2k 12-27-2012 04:37 PM

No! I didn't see it in person! Here:

Folsom's DC-3 on floats

I found a vid of a Buffalo Air DC-3 on skis now:

DC-3 on skis

Although way back when I was a young lad working for an airfreight company in Tulsa, I got to ride jumpseat in a DC-3 to Oklahoma City, where I hopped a Convair 580, I think, to Chicago.

earthsciteach 12-27-2012 04:47 PM

That is an impressive video. That Piper PA-20 Pacer in the foreground of the opening shot caught my eye.

dgjessing 12-27-2012 11:03 PM

Mine are ready for flight testing tomorrow. The original 3/4" wide wood skis just dug into the snow so I've added 2" wide plastic shoes to them, cut from a milk carton:


I also did away with the two music wire cross pieces, which, upon further reflection, probably really didn't do anything useful. Plus they cracked off when flexed :rolleyes:.

Here is the view from the underside, showing the spring's (adjustable) velcro mounting spot:


And here's the tail skid ski:


The wire skid is sandwiched between two pieces of velcro - easy to adjust the angle of attack and move from one plane to another.

Taxi tests in the back yard (with two different planes) were a success! The weather is looking good wind-wise tomorrow - I'll report back :D

dgjessing 12-28-2012 10:54 PM

They work great! :D


earthsciteach 12-28-2012 11:07 PM

Awesome! We have more snow on the way tomorrow, so hopefully I'll get to try it out in reasonable wind speeds.

flypaper 2 12-29-2012 01:53 AM

2 Attachment(s)
I copied these from the DC3 skis with the little wings on the back. Built for last yrs. flying. Had to take some of the curve off the front as they acted like up elev.and flew around with the skis almost pointed straight up.:DThese are on a Zoombi bipe Just got through making a set for the Flash 3D. They do work very well with no strings or rubbers attached. These are made from EPP foam with the wings made from $ Store foam and 1/16 carbon on the front edge of the wing for stiffening with hockey tape on the bottom to toughen them up and give a slicker surface.


dgjessing 12-29-2012 01:17 PM

Gord, I like that idea! May have to try it out :)

flypaper 2 12-29-2012 02:51 PM

Yeah, would adapt well to your skis. You may have to adjust the hinge point on the skis so they balance level just hanging. I had to add a bit of weight on the nose of one set of skis to balance right.


dgjessing 01-06-2013 10:43 PM

Went out and tried the skis again yesterday... didn't work as well :mad:. It's warmed up a bit and the snow is now wetter and the surface is not as "hard" as before, so the skis just dug in and got stuck. I had to hand launch, and landings mostly ended in nose-overs. My theory is that: a) - the skis were able to angle down too much due to the very light spring holding them in place for flight, and b) - they generated a lot of drag in the snow because they have no sides, and the wet snow piles on top of them as they ski along. So, version 2:


These are built up from two layers of $Tree foam in the center and then caps of 3/4" panel insulation foam on the outsides. More like floats than skis, which I think is just what's needed in the wet slushy stuff we've got on the ground now. They are covered in packing tape. Then there is a much more substantial wire strut holding them in place so they won't dive down under the surface. Taxi tests in the yard are promising. I'm planning on trying them for real tomorrow!

They also weigh half as much as the other ones - that can't hurt :D

dgjessing 01-08-2013 12:07 AM

They work well, but it wasn't much of a test today as there was a pretty solid crust on the snow. In fact, I was able to take off & land (gently) with the wheels (no skis) as long as I didn't hit a foot print in the snow.

I'm torn between wanting more snow so I can play with skis some more, and wanting :censor: winter to be over ASAP :)

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