Search found 10 matches

by bcohen5055
Sat Nov 09, 2013 7:13 pm
Forum: Ski/Snowboard Design and Layup
Topic: The dynamics of skiing
Replies: 13
Views: 9009

Richuck, maybe I wasn't so clear in what a was thinking about. I'm not looking for high level equations and calculations to design skis around but I'd like to have a conversation over what each variable does. A good example of this is stiffness. There is always a thread going on abut someone asking ...
by bcohen5055
Wed Nov 06, 2013 8:30 pm
Forum: Ski/Snowboard Design and Layup
Topic: The dynamics of skiing
Replies: 13
Views: 9009

The dynamics of skiing

Hello, everyone. I’ve been lurking on the skibuilders forum for almost 2 years now and I’ve learned a lot of great information. I do plan on eventually building skis but currently I’m more interested in truly understanding ski design. I’m a recent grad of a mechanical engineering program and while i...
by bcohen5055
Mon Oct 14, 2013 8:13 pm
Forum: Ski/Snowboard Design and Layup
Topic: covering veneer during pressing.
Replies: 22
Views: 11714

This may be a total noob question but just to clarify is this the general process?
staining/finish the veneer before layup
press the ski with a skim coat of resin
Sand/trim/finish ski
Coat with clear epoxy finish?
by bcohen5055
Sun Jan 27, 2013 9:55 pm
Forum: Yard Sale (non commercial)
Topic: Vectorply 22oz pre-slit TO YOUR WIDTH. 1/28 Deadline!
Replies: 12
Views: 7619

What is the widest section you can do? (50"- whatever everyone else orders)?

I have another non ski related project I may want this for...
by bcohen5055
Tue Oct 30, 2012 7:02 pm
Forum: Ski/Snowboard Design and Layup
Topic: Pure carbon skis?
Replies: 48
Views: 31981

I don't have an answer for your question about the stiffness of a powder ski but I'm sure some of the other more experienced ski builders can answer that. In regard to the poplar core, the carbon will stiffen it, this is the same thing that happens when you laminate it with fiberglass. The carbon fi...
by bcohen5055
Sun Oct 28, 2012 10:20 am
Forum: Ski/Snowboard Design and Layup
Topic: Pure carbon skis?
Replies: 48
Views: 31981

I can't speak with any real certainty without having done this but I can imagine you will have no torsional stiffness and turning will be very interesting. Take your profile core and try to flex it in torsion. When you add the unidirectional carbon you will only be adding axial stiffness so the tors...
by bcohen5055
Tue Oct 02, 2012 9:58 am
Forum: Ski/Snowboard Design and Layup
Topic: Experimenting with cuts of wood strips in core
Replies: 3
Views: 2936

Geometrically I understand what you are saying, and in general if you use the same wood it shouldn't make a difference. Some of the more knowledgeable tech guys on this forum may correct me but the main reason that multiple strips of wood are used over one large piece is to ensure the best grain dir...
by bcohen5055
Sat Jul 21, 2012 1:48 pm
Forum: Ski/Snowboard Design and Layup
Topic: Foam Mold for use with Vacuum
Replies: 26
Views: 17547

Foam works great as a mold for vacuum bagging, I have some photos showing a part I made entirely out of styrofoam molds (not skis) it worked great. What has been mentioned about surface finish is absolutely true. There is an amazing polyester based surfacing primer called duratec that will produce a...
by bcohen5055
Fri Apr 06, 2012 9:51 am
Forum: Ski/Snowboard Design and Layup
Topic: Why so much pressure?
Replies: 5
Views: 3031

Thanks for the helpful info I've been thinking it over and I'm gonna go with vacuum. As I start to design the mold are there any limitations I should think about in regard to how much camber, tip, and tail radius I put in the mold. I know I'm going to get camber loss but is there a certain safe oper...
by bcohen5055
Sun Apr 01, 2012 7:24 pm
Forum: Ski/Snowboard Design and Layup
Topic: Why so much pressure?
Replies: 5
Views: 3031

Why so much pressure?

I've been reading a much as I can lately about building skis and am planning to build a few pairs over the summer. I'm an engineering student and have been involved with a lot of composites work including wet layups, prepregs, and vacuum infusion methods. As such I'm very confident in my skills invo...