Raven Arks

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hadley
Posts: 44
Joined: Sun Jan 21, 2007 11:07 pm

Raven Arks

Post by hadley » Mon Feb 04, 2008 5:36 pm

Last week I pressed my first set of skis. I have taken picture, but the school security system is disabling my pictures so far. Things went pretty well. Firstly, I gave the system a trial run. I had missalignment problems but I will go ahead and test the skis. It will give me feedback about the flex patern. If the Flex is right I will start a second pair just like the first. One ski came out clean and the other one had the problems.

I had cut out my veneer top sheet to size so I could look down on the skis in the mold and align them in my vacuum system.

Ski Spect
180 Raven Arks
Concept: A light all round cascade back country ski with a eye on cascade pow. Increased the shovel width and height to help the skis break trial more easily and ride high in powder.

Top Sheet:Doug Fir Vertical Grain Veneer
Reinforcement: 20 oz Triax
2mm Front, 12mm platform, 3mm tail
Reinforcement: 20 oz Triax
Vibration Tape on sides 160 cm long
Base: Unsure but black and orange.
Dimensions: 128 95 115

Questions / Problems I encountered:
1. A small leak near one tail reduced my vacuum which may have resulted in the slight concave visible on the bases just inward from the tip and tail spacers. Possible solutions might be using a stethascope or plastic tube to listen for leaks. In addition would a pressure guage connected to the far side of the mold be a good idea, or just another opportunity for leaking.

2. My core slipped sideways and I couldn't tell it with the quilt batting. It is some 3/16 inch off. I need to work on an allignment system.

3. My one tip spacer slipped up on the core creating the ugliest blemish. An unsmooth base profile. Would veneer tape work to keep the core and tip spacers approximated. Or does epoxy disolve the veneer glue.

4. Should I prebend my bases with the metal edges attaced so they generate less resistance to the vaccum.

5. My offset has left one metal edge to be touced up with epoxy and one side wall cut through.

This process is incredibally cool. I can't wait to post the pictures. I may do it on my personal web site and just put in a link.

hadley
Posts: 44
Joined: Sun Jan 21, 2007 11:07 pm

Pictures

Post by hadley » Mon Feb 04, 2008 9:47 pm

Here is a Picture of me with the boards.
Image

Here is the worst defect.
Image

Here are several of the interested students with their projects.
Image

davide
Posts: 260
Joined: Wed May 04, 2005 7:13 am
Location: Tsukuba, Ibaraki-ken, Japan
Contact:

Re: Raven Arks

Post by davide » Tue Feb 05, 2008 12:31 am

hadley wrote: 1. A small leak near one tail reduced my vacuum which may have resulted in the slight concave visible on the bases just inward from the tip and tail spacers. Possible solutions might be using a stethascope or plastic tube to listen for leaks. In addition would a pressure guage connected to the far side of the mold be a good idea, or just another opportunity for leaking.
Plastic tube works fine. Also the second gauge is a good thing; usually vacuum connections are pretty tight, so don’t worry about adding a second one.

hadley wrote:. My core slipped sideways and I couldn't tell it with the quilt batting. It is some 3/16 inch off. I need to work on an allignment system
Usually I screw the core and the base on the mould with a couple of screws.
Sometimes I fix the base on the MDF mold with some pieces of double side tape.
hadley wrote:My one tip spacer slipped up on the core creating the ugliest blemish. An unsmooth base profile. Would veneer tape work to keep the core and tip spacers approximated. Or does epoxy disolve the veneer glue
I use small metal stiches (I don’t know the name in English), like the one used to punch paper sheets together.
hadley wrote: Should I prebend my bases with the metal edges attaced so they generate less resistance to the vaccum
Yes, much better.


Longboards and skateboards are a good way to practice vacuum bagging.

plywood
Posts: 499
Joined: Fri Oct 13, 2006 2:13 am
Location: wilen, switzerland
Contact:

Re: Raven Arks

Post by plywood » Tue Feb 05, 2008 7:26 am

i wish i had such a teacher! nice work!

davide wrote:
hadley wrote:. My core slipped sideways and I couldn't tell it with the quilt batting. It is some 3/16 inch off. I need to work on an allignment system
Usually I screw the core and the base on the mould with a couple of screws.
Sometimes I fix the base on the MDF mold with some pieces of double side tape.
double side tape works well, BUT if you use thin base material the tape creates some bumps in the base. happened to a friend of mine, and the bumps were pretty deep so he couldn`t get them flat with stonegrinding...

but generally i second what davide wrote. prebend the edges to match the radius in tip and tail and prebend the woodcores - this will cause much less trouble when pressing, alignment gets really confortable
plywood freeride industries - go ply, ride wood!

hadley
Posts: 44
Joined: Sun Jan 21, 2007 11:07 pm

First trip out with the skis

Post by hadley » Sun Feb 10, 2008 9:28 pm

The conditions were good for testing skis, but bad for skiing. Rain at the base and frozen crust at the top of Mt. Hood. I skiied of piest enough to get a feel for if the skis would hold an edge. I was able to ski them hard with no problems. I used my Rosignol Megabangs as the template shape and then just let the width of the edges give me my wider ski. This lets the Megabangs work as a control test. The skis I made handle very reliably. I skied them just as fast and hard as I could but didn't fall all day. They are a bit more grabby on hard ice, but that my be the result of fresh edges, or it could be the result of concabity of the tips and tails from the press flaws. I had expected the inconsistency in the base shape to effect the handling more, but grinding the bases took a lot of that out. This is more then I could have hoped for.

This has been a really great experience. I wanted to thank everybody who has helped me out. I am excited to start my next pair.
John

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