I hope to finish them soon and with details to follow...
Kam's skis
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Kam's skis
I have two new pairs in the works. One pair will have a maple core, mixed with steel and a sprinkle of other ingredients. The other pair centers around a popular + fir + pine core.
I hope to finish them soon and with details to follow...
I hope to finish them soon and with details to follow...
Skis are done:
I was in a hurry to finish these. It's not my best work, but they will work just fine. The left and right pair are 180 cm and 175 cm long, respectively. For some reason both tail spacers on the left pair shifted considerably. I have a minor convexity problem with the left pair above the binding too, but I know what caused it. Then there's the small white piece of unidentified tape stuck to the base of the right pair. Where in the world did that come from?
As promised, here are the details:
Left pair
Shape: 130-95-110 mm;
Core: maple, 11mm thick underfoot;
Composite layer: base layer is 22 oz triax and on top of the core sits a platform of 22 oz glass for the bindings and then a layer of pre-preg glass with 6, ~1/16" carbon fiber strips weaved lengthwise (acknowledgements to a leading ski manufacturer);
Sidewalls: flame-treated white uhmw (the same stuff available from our store);
Vibration/damping gizmo: I've been experimenting with different types of rubber and metal sandwiches placed strategically throughout the ski. So far I have enjoyed how my skis have performed compared to no embedded gizmo, so I continue to use and test different designs. I have not done too much analysis to characterize or quantify the contributions of these gizmos, but for now the smile they put on my face when I ski is good enough for me. This time I incorporated a 200mm x 60mm x 1.5 mm piece of rubber about 12" behind the tip. Riding above this layer is a 200 um thick steel foil 1.25 times wider than the rubber and about 3 times longer. The foil covers approximately the upper 1/3 of the ski. Holes were punched into the steel to enhance bonding. Additionally, I used VDS in other areas to provide a shear layer.
Overall, the flex feels very nice and even. The maple sure does add a little weight compared to the other ski which is made from pine + fir + poplar.
Right pair
Pretty much the same dimensions as the left pair, but slightly shorter. I chose the mixed-wood core to keep the weight down. Like it's bigger brother, the core was 11mm thick underfoot. I used the same vibration/damping gizmo, but instead of the pre-preg glass layer, I used two layers of 6 oz. biaxial glass. The iridescence topsheet changes hue depending on what direction you stare at the skis. I initially intended to make the colors more vibrant, but at the last minute changed my mind. These skis have a very soft flex and this was by design. I used flame-treated black uhmw sidewalls with black tip/tail spacers. No shifting occured in this pair. Lastly, the skis were pressed at 80 psi @ 150 F for 10 minutes, then the temp was ramped to 190 F for 40 minutes. The air temp was nowhere as cold as it was in winter so there was a smaller temp gradient through the thickness of the ski, minimizing the temp-induced camber. The skis have about 10 mm of camber -- just perfect.
On a scale of 0 to 10 with 10 being the highest, i rate the quality of my work as 7.0. Now let's just hope they don't delam or break in half.
I will ski the right pair next week and hand over the left pair to a close friend. Because of the average quality, I promised my friend that I'd make him another pair, but only after I finish my cnc machine....
I was in a hurry to finish these. It's not my best work, but they will work just fine. The left and right pair are 180 cm and 175 cm long, respectively. For some reason both tail spacers on the left pair shifted considerably. I have a minor convexity problem with the left pair above the binding too, but I know what caused it. Then there's the small white piece of unidentified tape stuck to the base of the right pair. Where in the world did that come from?
As promised, here are the details:
Left pair
Shape: 130-95-110 mm;
Core: maple, 11mm thick underfoot;
Composite layer: base layer is 22 oz triax and on top of the core sits a platform of 22 oz glass for the bindings and then a layer of pre-preg glass with 6, ~1/16" carbon fiber strips weaved lengthwise (acknowledgements to a leading ski manufacturer);
Sidewalls: flame-treated white uhmw (the same stuff available from our store);
Vibration/damping gizmo: I've been experimenting with different types of rubber and metal sandwiches placed strategically throughout the ski. So far I have enjoyed how my skis have performed compared to no embedded gizmo, so I continue to use and test different designs. I have not done too much analysis to characterize or quantify the contributions of these gizmos, but for now the smile they put on my face when I ski is good enough for me. This time I incorporated a 200mm x 60mm x 1.5 mm piece of rubber about 12" behind the tip. Riding above this layer is a 200 um thick steel foil 1.25 times wider than the rubber and about 3 times longer. The foil covers approximately the upper 1/3 of the ski. Holes were punched into the steel to enhance bonding. Additionally, I used VDS in other areas to provide a shear layer.
Overall, the flex feels very nice and even. The maple sure does add a little weight compared to the other ski which is made from pine + fir + poplar.
Right pair
Pretty much the same dimensions as the left pair, but slightly shorter. I chose the mixed-wood core to keep the weight down. Like it's bigger brother, the core was 11mm thick underfoot. I used the same vibration/damping gizmo, but instead of the pre-preg glass layer, I used two layers of 6 oz. biaxial glass. The iridescence topsheet changes hue depending on what direction you stare at the skis. I initially intended to make the colors more vibrant, but at the last minute changed my mind. These skis have a very soft flex and this was by design. I used flame-treated black uhmw sidewalls with black tip/tail spacers. No shifting occured in this pair. Lastly, the skis were pressed at 80 psi @ 150 F for 10 minutes, then the temp was ramped to 190 F for 40 minutes. The air temp was nowhere as cold as it was in winter so there was a smaller temp gradient through the thickness of the ski, minimizing the temp-induced camber. The skis have about 10 mm of camber -- just perfect.
On a scale of 0 to 10 with 10 being the highest, i rate the quality of my work as 7.0. Now let's just hope they don't delam or break in half.
I will ski the right pair next week and hand over the left pair to a close friend. Because of the average quality, I promised my friend that I'd make him another pair, but only after I finish my cnc machine....
Well, at least you didn't get any garbage between the layers... I had one pair that somehow managed to pick up a piece of dowel material under the top sheet... when the ski came out of the press, it had a giant wart! So, like a human wart, I sliced the top sheet, retrieved the cancerous piece, and patched it back together.
Want skis Better, Cheaper, Faster and much much Cooler... build your own.
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MartinJern
- Posts: 48
- Joined: Sat Jul 28, 2007 1:27 pm
- Location: Sweden
I enjoyed skiing on the right pair this past weekend with friends from Seattle and Salt Lake City. Sorry G-man that we could not meet up, but soon I hope.
The original weekend plan was to camp/ski at Lassen NP, but the unappealing weather forecast made us reconsider. I can handle rain. I can handle heavy snow. I can even handle no snow on skis with a big smile. But lightning and ski poles gives me a negative 'vibe'. Instead, we drove south along HW395, encouraged by the 30-40% of precip, in hopes of skiing Tioga Pass. When we arrived at the 120/395 junction early Sat. afternoon, we found the pass closed until further notice. With no easy access to the snow, we camped near the gate for the night. Five inches fell overnight, but the pass was still closed. So Sunday morning we drove further south, first stopping at the base of McGee Mtn., just a stone's throw southeast of the 203/395 junction. It would have been an adventure to log in turns on McGee, so we continued for 10 more minutes down 395, stopping to debate over Tiptop and Prospect Peak, neighbors of McGee. It was a split decision in the group, so we drove to higher ground up 203, stopping at Lake Mary, then skinning from the car to Mammoth Crest, passing Crystal Crag. It was snowing heavily when we stopped.
My skis were great. I enjoyed the soft flex and sidecut very much. I had not grinded or waxed the bases so they were slow and grabby, but other than that they skied wonderfully. This is one of my favorite skis so far. I have many favorite skis, by the way.
I inspected the sidewalls and tip/tail. No delams so far so I'm assuming the flame treatment is working. Finally. Also, I am using a different type of VDS that will soon be available in our store. The rubber feels more elastic and is tan in color, like a latex glove. Bonding seemed good.
After our tour, we hit a local laundromat to dry our ski gear, sleeping bags, etc. That night we camped about 20 miles east of Carson City. No rain this time. On Monday morning we drove up HW431 and toured up to Tamarack. The weather was decent and snowing a bit at the top. We skied a nice semi-tracked line and again I felt that my skis worked really well. I was on G-3 Targa bindings as opposed to my BD 01's. I will do more testing in a few weeks in the NW to see how they continue to handle, but so far so good.
The left pair I handed over to a friend as a gift.
The original weekend plan was to camp/ski at Lassen NP, but the unappealing weather forecast made us reconsider. I can handle rain. I can handle heavy snow. I can even handle no snow on skis with a big smile. But lightning and ski poles gives me a negative 'vibe'. Instead, we drove south along HW395, encouraged by the 30-40% of precip, in hopes of skiing Tioga Pass. When we arrived at the 120/395 junction early Sat. afternoon, we found the pass closed until further notice. With no easy access to the snow, we camped near the gate for the night. Five inches fell overnight, but the pass was still closed. So Sunday morning we drove further south, first stopping at the base of McGee Mtn., just a stone's throw southeast of the 203/395 junction. It would have been an adventure to log in turns on McGee, so we continued for 10 more minutes down 395, stopping to debate over Tiptop and Prospect Peak, neighbors of McGee. It was a split decision in the group, so we drove to higher ground up 203, stopping at Lake Mary, then skinning from the car to Mammoth Crest, passing Crystal Crag. It was snowing heavily when we stopped.
My skis were great. I enjoyed the soft flex and sidecut very much. I had not grinded or waxed the bases so they were slow and grabby, but other than that they skied wonderfully. This is one of my favorite skis so far. I have many favorite skis, by the way.
I inspected the sidewalls and tip/tail. No delams so far so I'm assuming the flame treatment is working. Finally. Also, I am using a different type of VDS that will soon be available in our store. The rubber feels more elastic and is tan in color, like a latex glove. Bonding seemed good.
After our tour, we hit a local laundromat to dry our ski gear, sleeping bags, etc. That night we camped about 20 miles east of Carson City. No rain this time. On Monday morning we drove up HW431 and toured up to Tamarack. The weather was decent and snowing a bit at the top. We skied a nice semi-tracked line and again I felt that my skis worked really well. I was on G-3 Targa bindings as opposed to my BD 01's. I will do more testing in a few weeks in the NW to see how they continue to handle, but so far so good.
The left pair I handed over to a friend as a gift.
Last edited by bigKam on Thu Jun 05, 2008 8:13 pm, edited 1 time in total.
the irridescent topsheet on the right pair gives those skis a really professional look. i know you used a dark colored fabric underneath, but it almost doesn't matter what color, because the skis look indigo blue from pretty much every angle. i wonder how they'd come out with light colored or white fabric underneath? anyway, nice work on those, they look really good. did you come up with a name for them yet?
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knightsofnii
- Posts: 1148
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