Top Cassette

[uncski]

Been reading these forums for what seems like ages now. Would have liked to start building a press and learn hands on like many of you have done, however I live in North Carolina and would like to be closer to a ski hill to test prototypes other than the 15 days a year I spend out west. I ride Armada JJ's and like the idea of a capped ski with sidewall under the running length only.

Anyway, my question is about the top cassette for cap skis. I'd be interested in using a thick rubber as the top cassette being pressed by the cat track so that it would conform to whatever it was being pressed on. I'm thinking it would provide even pressure at variable horizontal depths (something a cat track can't do). My thought is I won't have to have CNCd top cassettes made and I could just use rubber to conform to any ski design. Trying to post a link to a material, but can't due to post count. rubbersheetroll DOT com

1) Is this a ridiculous idea that any real ski builder would dismiss?
2) Would it provide enough pressure?
3) Is there a way I could make it so that epoxy doesn't stick to it?

Appreciate any feedback, including "you're an idiot".

[chrismp]

i think there was a post way back mentioning hobby builder or even a company doing the exact same thing as you describe.

the only problem i see is that you don't get even pressure since the rubber sheet will exert more pressure in the areas where it gets squeezed.

[uncski]

Appreciate the reply! Eventually I'll get to building a press and trying it out, wish I could contribute more in the meantime.

[chrismp]

found the thread i was talking about: http://www.skibuilders.com/phpBB2/viewt ... cap+rubber

check out the link to the site posted in there. they have cut the shape of the ski into the sheets though.

[uncski]

That rubber top mold was used for a vacuum setup though correct? Sorry the pictures are quite confusing as it seems they are going through their standard press method as well as a vacuum setup to create the cap ski (not speaking french probably doesn't help).

I was hoping to find a way to use rubber to create cap skis on a traditional press, that way I have more flexibility in my ski design.

[uncski]

Never mind, I think you're right that they are using the rubber top to get the cap in a press. I wonder if you could use a softer rubber that would conform without having the shape cut into it.

[skidesmond]

A few people have made capped skis and boards. Check out Kam's http://www.skibuilders.com/phpBB2/viewtopic.php?t=3468

I think he made a top mold to go over the ski. That requires CNC precision.

[uncski]

Thanks Desmond! Though I'd like to have a shop like that one day, I don't know if cnc'd cassettes will be in the budget from day 1. We'll see if I can find a local that will do it for cheap, beer or free.

[skidesmond]

Now you're thinking!

[yack]

Hi everybody,

I asked The Whyte Crystal Family about their silicon top cassette (http://www.skibuilders.com/phpBB2/viewt ... cap+rubber ) and they told me they have used it only one time, because the result wasn't really good....

[telehead]

I have tried everthing I can think of. Thick rubber, thin rubber, hose with no cat track, thinner more plyable hose, hose under cat track with hose above, bla bla bla! I think the only way is with a negative die on top. Then there is still the issue of keeping everything in line when pressing. Spend some time and make a top die, I have done so without a CNC and I am having great, consistant results...kt

[chrismp]

could you elaborate a bit more on how you built your top die? i guess i'm not the only only interested to see how it can be done without a cnc!

[mattman]

uncski, your idea is absolutely possible. I did a research project on that exact idea. There are a lot of things to consider that make a big difference (rubber durometer, pad thickness, pad width, pressure...). It is possible to model all of your parameters and determine your resulting cap-fillet. It was my plan to write a program for this process (which I did) and use it build a variety of cap skis (which I did not do). In the end the pad is a large investment and it is easier to just find a sidewall material that you prefer to work with...UHMW isnt the only option. But who knows...might try it some day (especially if your results come out good )

[mattman]

OH, and it provides plenty of pressure...the sheet metal industry has been using rubber-pad forming and stamping for years at MUCH higher pressures.

[Brazen]

It's a pain to match the forms, and you are limited to the exact size board/skis every time with a cap process. Plus, cap sucks. Looks nice though!