Wheel Penetration Skis for 26" Goodyears

I'm not planning on hitting anything. Once upon a time I was given a set of damaged Federal? 2000 skis. The tunnel was buckled under the pedestal. Don't know what or how it hit.

This video https://vimeo.com/151403825 shows the bottoms of the Rosti skis. Notice the flat section under and just ahead of the tire. There is an upward curvature just behind the tire which is a big help. However the Rosti tire is on top of the ski. That section needs stiffness enough to avoid buckling. Easier to do with composites. The curved top section in addition to it's aerodynamics provides torsional strength to the entire ski, not bottom stiffness. My ski will have this in aluminum.

I have yet to hear what the bottom thickness is of a set of aluminum skis. Anyone? Retract bottoms (not the slide)? Frenchy used 6061-T6 x .100". The -T6 is harder and more resistant to impact damage than -T3. I have 2024-T3 x .090" which is why the plan is to double up the bottom with 2024-T3 x .040".

I can also eliminate the double layer by using cross angles to provide the stiffness on the flat section. Perhaps this would be a better idea eliminating the layer of .040"? There would be less labor forming compound shapes and less weight. Now upon further thought perhaps this is a better route to take? I'm not too concerned about the edges taking a bit of punishment where a few dings wouldn't be too troublesome.

There will be two parallel tunnels attached to and stiffening the bottom which transfer the loads to either side of the wheel axle attachment.

What do you abusers of skis in Alaska think? You mechanics who repair the damage? Dave Caulkins? mike mcs?

Rather than "heatin an a beatin" compound curves in the .090, consider shaping a hardwood block to your ski bottom profile and then hydro forming the skins on a press (a la mcs mike)? If yluu can manage it, it would be awesome for repeatability.

I have a homemade planishing hammer using a rivet gun and a piece of railroad track which does a nice job of moving metal cold.

English Wheel would work best for compound curve, i bought one for $300 .

Frenchy

https://youtu.be/qFRF-kptifk

This video is better to show how to make curve on an English Wheel https://youtu.be/eRvJHsNcnLA

I have used an English wheel to make new wing and stabilizer tips for my 185. This will be with the planishing tool. I agree that the English wheel would be a good tool for this. I just don't have access to it any more and to buy one for this job would be excessive.

I tried to show you some pictures of small progress. Couldn't get the pictures to post. Have expended a lot of hours to machine one fitting to attach the ski to the gear. Another one to go.

Photos posted for Skywagon

Thanks Tom,

Seaworthy said:

Click to expand...

This shows the sequence of events starting from a tree which was turned into a wooden prototype. Next step was to change a 22 lbs chunk of cold rolled steel into a 2.2 lb fitting which bolts to the gear picking up two of the bolts which hold the brake bracket and the other end where the shock strut attaches.

The ,080" aluminum under the parts will eventually become a ski.

The other three pictures show the fitting in place. This is just the inboard fitting. There will be another similar to the outboard fitting used by Airglas.

The round disc is the spacer which is needed to align the brake housing with the disc.

Nice work Pete you made a pile of chips making that.FYI Summit wanted $1500 for two of those mounts when I inquired last week and they were not that fancy.

Bill

Thanks Bill, From the pictures that I've seen of the Summit brackets, you could easily weld up a set of those for short money.

I could have made mine by welding flat stock. I had a piece of cold rolled looking for something to be made into and I wanted to make something on my mill. Efficiency wasn't part of my thinking in this case. Strictly "I want to do it". I'm fascinated by fine machined parts and want to improve my own capability.

skywagon8a said:

Thanks Bill, From the pictures that I've seen of the Summit brackets, you could easily weld up a set of those for short money.

I could have made mine by welding flat stock. I had a piece of cold rolled looking for something to be made into and I wanted to make something on my mill. Efficiency wasn't part of my thinking in this case. Strictly "I want to do it". I'm fascinated by fine machined parts and want to improve my own capability.

Click to expand...

Well it looks like you did it. Nice work!
VT Glenn 40M

Did you ever finish these skis? Cool project.

No I did not. Because we haven't had enough ice on the lake to be considered safe since I started the project. I figured I would just be too tempted to try them and end up getting in trouble. So the safest plan was to not finish them.