Camber to tip transition

For discussions related to ski/snowboard construction/design methods and techniques.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

Post Reply
User avatar
falls
Posts: 1458
Joined: Tue Oct 27, 2009 5:04 pm
Location: Wangaratta, Australia

Camber to tip transition

Post by falls »

Just looking fo people's thoughts on how they design the transition from the cambered section to the up curve in the tip.
Two ways I figure to do it:

1. The camber section is simply an arc and the tip arc meets it tangentially (so the tip actually goes down a bit further before it starts going back up - if that makes sense).

2. The camber section is more like a sine wave so it's ends go back to being parallel to the ground at the contact point. The tip arc stil meets it tangentially, but immediately begins to rise from the transition point.

Some exagerated drawing examples

1.
Image

2.
Image



Any opinions and thoughts on how (or even if) this affects the ride. Thanks
Don't wait up, I'm off to kill Summer....
OAC
Posts: 961
Joined: Thu Jul 23, 2009 9:34 am
Location: Sweden
Contact:

Post by OAC »

I've also struggled with this "theory" and didn't really come to any conclusion. But I decided that the transition point should be the lowest point on a (my)cambered ski. And it should strive to touch the snow "first".
That would be your number 2.
skidesmond
Posts: 2338
Joined: Tue Apr 07, 2009 3:26 pm
Location: Western Mass, USA
Contact:

Post by skidesmond »

I use Sno-Cadx so it does it for me. I still use the traditional design, the camber ends at the transition point which is the point where the tip begins and is the same point that touches the ground, which is the same point where the running length starts. It would be your diagram 2.
twizzstyle
Posts: 2207
Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

I do your method one. My camber section is a circular arc that meets tangentially with the tip, also a circular arc.
agiocochook
Posts: 72
Joined: Tue Apr 27, 2010 1:18 pm
Location: White Mts, NH

Post by agiocochook »

FWIW, I've been doing something more like the second method. I run the camber arc to the ends of the running length and start the tip arc at the end of the camber arc with a horizontal tangent. I then draw a spline starting 2 cm before the end of the camber arc, going through the end of the camber/start of the tip point and ending 2 cm into the tip arc to smooth it all out.

TS, using your method, do you compensate for the increase in camber height and/or running length? Or, is it not significant enough to worry about?

Scott
User avatar
SHIF
Posts: 280
Joined: Sat Jul 14, 2007 7:43 pm
Location: Wasatch Mountains
Contact:

Post by SHIF »

twizzstyle wrote:I do your method one. My camber section is a circular arc that meets tangentially with the tip, also a circular arc.
+1 for diagram #1.

When you de-camber the ski (by standing on it) the transition point naturally becomes the contact point and the tip rise also increases by several millimeters.

I've always designed skis using tangent arcs but my latest creation will have elliptical rocker profiles and a low cambered arc in the middle.

I have been experimenting with how long to make the effective edge relative to the running length. My next pair will have its turning edge running well past both contact points up into the rockers.

I can't imagine creating patterns without a real CAD program.

-S
twizzstyle
Posts: 2207
Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

On my Piggy Sticks, there was a section of zero camber in the center, then a large radius arc for the rocker, which transitioned to a tighter radius for the tip. Still all circular arcs though.
sammer
Posts: 933
Joined: Wed Dec 19, 2007 10:37 pm
Location: Fernie B.C.
Contact:

Post by sammer »

So I'm doing it all wrong?
I just bend some MDF with clamps, various thickness wooden shims, and a hot glue gun until it looks right.

Image

Tip/tail shapes I freehand draw on a piece of paper, transfer that to a template



Put it all together and so far it seems to be working.
If I had to learn a cad program to build skis I wouldn't have gotten very far.

sam
You don't even have a legit signature, nothing to reveal who you are and what you do...

Best of luck to you. (uneva)
OAC
Posts: 961
Joined: Thu Jul 23, 2009 9:34 am
Location: Sweden
Contact:

Post by OAC »

sammer wrote:So I'm doing it all wrong?

sam
No way! You're a true purist! :)
Post Reply