RISD sustainable ski exploration

MontuckyMadman · Post by **MontuckyMadman** » Thu Jan 20, 2011 9:19 pm

Ah. Ow. Risd kids makin skis. Damn. Now its really not cool.
Nice skis. Kinda weird. Love the zebra wood.

RISDski · Post by **RISDski** » Sat Jan 22, 2011 7:30 pm

To clean up our edges we used a wedge to hold the skis to a vertical sander at an angle. We tried a router with no success. How do you guys go about it? Anyone have pictures of the router process?

SHIF · Post by **SHIF** » Sat Jan 22, 2011 11:57 pm

RISDski wrote:To clean up our edges we used a wedge to hold the skis to a vertical sander at an angle. We tried a router with no success. How do you guys go about it? Anyone have pictures of the router process?

After trimming away the flash using a Bosch jigsaw, I clean up the ski using a hand-held Milwaukee angle grinder with a 4.5 inch flap wheel sanding disc, 40 grit. With a little practice its easy to make nice clean vertical sidewalls. Make long smooth strokes and stop when you see the sparks coming off the steel edges. This is only the first step in my ski finishing process.

I use a router to bevel the top edges of the skis leaving a nice vertical sidewall parallel to and above the edges.

This photo shows my sidewall beveling set-up. My router is mounted to an aluminum plate and is cantilevered over the ski. The ski is supported on some strips of MDF that are bent by a small piece of hardboard wedged underneath.

I use a 22.5 degree angle bit with a bottom bearing. The bearing rides along the steel ski edge. I can achieve a sidewall shape having about 5 to 6 mm of vertical sidewall below the bevel. It is imperative to keep downward pressure on the ski as you push it past the router. The ski base must stay in contact with the MDF at all times. Make three or four passes, lowering the router for each pass. Feed the ski in the direction so the router bit "climbs", not "plunges" into the material.

These are old pics showing a ski having UHMW sidewalls. Currently I use Macaranduba (Brazilian redwood) for sidewalls which makes for a superior ski.

-S

RISDski · Post by **RISDski** » Sun Jan 23, 2011 11:21 am

Shif-

Thanks so much for the router info, that is extremely helpful. We purchased a similar router bit last spring, but when we attempted cleaning up the edges we clamped the ski down and moved the router as opposed the moving the ski along the router. We got about six inches down the ski before it took a large bite out of the sidewall of our test ski. Have you had any similar problems with your method?

-Thanks!

RISDski · Post by **RISDski** » Sun Jan 23, 2011 12:08 pm

Hey guys-

Thanks for all the feedback! We have a question for everybody about edge bending. We don't have a custom edge bender, so we used a di-acro for the tips and tails. It worked moderately well, but since our tips were not true radii the bends were never completely accurate. I've noticed that on some of volkl and rossi skis the edges end before the end of the tip and tail and they use solid pieces of steel sanded down to the desired tip shape. Has anyone experimented with this method?

SHIF · Post by **SHIF** » Sun Jan 23, 2011 5:39 pm

RISDski wrote:Shif-...Have you had any similar problems with your method?

-Thanks!

No issues so far. I concentrate on keeping the ski down. Others have used a similar approach but improved upon with the addition of spring loaded pressure rollers to force the ski down.

There are several threads about 3/4 tip wrap edges, use the forum search tool. I prefer full wrap edges and achieve nice bends by first annealing the steel edges where the bends are to be made. They remain full hard temper where it counts, along the turning radii of the ski.

-S

Brazen · Post by **Brazen** » Sun Jan 23, 2011 5:52 pm

When you anneal the metal, how hot do you get it?

SHIF · Post by **SHIF** » Sun Jan 23, 2011 6:13 pm

Brazen wrote:When you anneal the metal, how hot do you get it?

"Orange hot" using a simple propane torch. The tabs get glowing very bright. Experiment with some cut off scraps to determine the appropriate amount of heat needed. Then let them cool to room temperature and scrub off the soot using a brass brush or wire wheel in a drill motor. They bend easy by hand, but it’s still best to wear gloves. They are also easy to cut using a hack saw and trim to exact fit using a mill file or mini belt sander.

Using my base template, I make some bending templates from 1/8" hardboard. It’s best to slightly over bend the edges and then unwrap them to fit the template. Be sure to view them from the bottom side to check how tightly they match the template. You can smack them with a hammer as needed, the template is disposable. To make really tight bends you need to snip off pieces of the tabs. This is easy to do using wire cutters, wear eye protection!

-S

MadRussian · Post by **MadRussian** » Sun Jan 30, 2011 5:54 pm

great looking skis.

RISD is 10 min from me.

doughboyshredder · Post by **doughboyshredder** » Sun Jan 30, 2011 5:59 pm

SHIF wrote:
RISDski wrote:Shif-...Have you had any similar problems with your method?

-Thanks!
No issues so far. I concentrate on keeping the ski down. Others have used a similar approach but improved upon with the addition of spring loaded pressure rollers to force the ski down.

There are several threads about 3/4 tip wrap edges, use the forum search tool. I prefer full wrap edges and achieve nice bends by first annealing the steel edges where the bends are to be made. They remain full hard temper where it counts, along the turning radii of the ski.

-S

The most important part of the edge is where it is most likely to impact rocks and other obstacles. IMO that area is directly underfoot and at the radii of the tips, where you are ruining the temper. Also, if you're not sandblasting the edges after annealing you are drastically increasing your chance of de-lams, again at the most likely place to have problems. Annealing your edges is not a good thing to do IMO.

SHIF · Post by **SHIF** » Sun Jan 30, 2011 8:20 pm

You make a compelling argument for not annealing edges.
In my experience delamination has not occurred, and the tail ends of my skis get fairly abused from repeated strikes with the parking lots, walkways, and tram floors. I have had several rock (cliff face) hits underfoot, where the edges are at full temper. These things are seemingly indestructible. I’ve had chunks of granite sticking out of the base but the edges remain unscathed.
If were building snowboards I would not anneal the edges, the bend radii do not require it.

-S

MontuckyMadman · Post by **MontuckyMadman** » Sun Jan 30, 2011 8:39 pm

you have read the head monkey tests that say that not reblasting the edges affects the bond right?
Better off going 3/4 wrap if you cant reblast maybe.

doughboyshredder · Post by **doughboyshredder** » Mon Jan 31, 2011 10:16 am

or just get more practice bending without annealing. It can be done. We had to do it for race boards that we built. Break some of the teeth off if necessary. (easiest way to do this is with pliers, bend them up and down a few times and they snap right off). Then over bend, bend back, over bend, bend back, over bend, bend back. The more you bend the steel the softer it gets.

RISDski · Post by **RISDski** » Thu Feb 17, 2011 12:58 pm

We just got terrible news. Went to take our skis in to get bindings on and turns out that our basalt plate that we laminated into the core is not long enough for the binding. Which would mean screws would be going directly into balsa and would just pull out. Can anyone think of solutions that we could use to fix this problem in these skis. We would hate to throw out skis because of this. Any suggestion is helpful.

Brazen · Post by **Brazen** » Thu Feb 17, 2011 1:14 pm

mark the spot, helicoil with epoxy?

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RISD sustainable ski exploration