Nodd

Well for those living up near the top end of the planet Winter is upon us. While many spend this time hibernating in the warmth of their workshops, I decided to slap some cheap skis on my plane & venture out into the snow...



And then, just when I was starting to have fun, total buzz-kill...



I won't mention the brand name but I expect you've come across these at your local hobby shop. Did I mention they were cheap? As with most things, you get what you pay for. So I tossed em in the bin, fired up the CAD software & set about designing my own skis...

Download Plans (PDF)



I've heard Formica (used in counter tops etc) makes a pretty good ski material. Tough as nails & best of all, nice & slippy on one side...



I used a heat-gun to help form the ski-tip...



The ski's spine I made from scrap pine. I used contact cement to temporarily tack my templates to the wood...



A little time at the scroll-saw, some sanding & we have a pair of ski-boots...



Clamping while the epoxy cures...



That looks like it might work...



Happy with Mommy & Daddy ski I produced a Baby ski too...



Masking off the slippy side of the Formica in preparation for some paint...



A dusting of primer...



A coat or two of black & they're looking the part...



While this looked good on the bench, as expected when I picked her up the skis flopped around all over the place. My el-cheapo skis used a spring to hold the skis in a slight tips-up attitude. While I could have copied that system I chose to take a slightly different route...



A length of wire bridged between the forward section of the two skis attaches to a spring. This holds the tips up while in the air & also helps keep them parallel to each other...



String attached to the rear acts as a stop & maintains the tips-up attitude. Once she touches down the string goes slack allowing the skis to follow the terrain...



I slipped the string under a screw & washer so that I can easily adjust the angle of the skis...



The baby ski is a little simpler, looks like it'll work fine with just a spring...



Well there she is, ready for some fun in the snow...



No doubt there's lots of other DIY ski designs out there & this obviously is not the only way to go but I figured I'd share what I came up with.

Download Plans (PDF)

Let it snow, let it snow, let it snow!

Oh yeah & before you ask, the plane is a Spacewalker by House of Balsa. Awesome park flyer & a lot of fun to build.

kenh3497

Very nice there Nodd About the "let it snow"...... Bah Humbug

Ken

scale only 4 me

My Feedback: (158)

5 stars Nodd,, that's awsome

flyinwalenda

My Feedback: (5)

Good job ! They will last longer than the store bought plastic ones...unless you can fine some ot the older aluminum sets !
I've made a few sets out of formica years ago and they are still holding up well. One some planes I had to install some scags in order to turn. The formica ones will break after awhile but it's usually years before they crack.
I make torsion arms out of good music wire and wheel collars and install them on the axle and into the wood spline. to keep the tips up. Your system looks good too.
keep some wax on the bottoms too!

Nodd

Thanks guys.

Yeah I don't expect these to last forever but I figure they should hold up for a season or two if not more. The torsion arm method is definitely a slicker install no doubt. I may play around with setting them up that way but for now I think this Heath Robinson setup should work fine. Well here's the flight report...


Flight Report
Well I tested the skis today even though most of the snow at our field had melted. I did some taxi runs on small areas of the white stuff. I was really impressed with how fast she got up & moved, barely had to blip the throttle & she was zipping along. Unfortunately there wasn't enough snow to try turning around so I didn't get to see how the tail-ski steers. She did track nice & straight though. I also tried her on the grass but she just tipped forwards. The same thing happens on grass with 3" wheels on this model so that didn't surprise me.

Anyway happy with the ground handling I set her up on a largish patch of snow & let her rip. Talk about whip-lash, she accelerated to flying speed in just a couple of feet & was airborne almost immediately. Apparently snow Vs Formica is utterly frictionless *grin*.

I expected to have to mess with the elevator trim but other than a notch or two of left aileron she flew hands off just fine. I did notice she flew a tad heavier, was a little more twitchy during high G maneuvers. That was to be expected though, the skis are heavier than the wheels but not by much. Overall she pretty much flew as normal.

I should probably note this plane has a history of losing its main gear during heavy landings. It's actually rare that I go home with the gear still attached to the plane but it's an easy fix so I've not done anything about it. Knowing this I was reluctant to land until I'd had some fun flying her. But my club mates were egging me on to try some touch-n-goes. I did a few & she skipped happily along the snow & back up into the air. Then of course on the fourth attempt I missed the snow & hit a patch of grass. SNAP off came the gear with my new skis attached. Oh well, that was the end of that for the day.

Overall I'm quite pleased with the skis. I'm looking forward to more testing, assuming it snows again. Let it snow, let it snow, let it snow!