Pressing learning curve

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gketcham
Posts: 102
Joined: Mon Sep 13, 2010 3:28 pm

Pressing learning curve

Post by gketcham » Fri Dec 16, 2016 7:57 am

How many pairs of skis did you have to make before you really felt like you hit your stride on getting everything pretty on-point when you pressed? This is just a fun topic. I have pressed four pairs of skis and I am still feeling like I learn something new every time.

JukeSnowboarding
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Joined: Wed Oct 13, 2010 7:21 am
Location: Mass

Post by JukeSnowboarding » Fri Dec 16, 2016 10:06 am

Ive pressed over 20 boards and feel every board I make is better than the last. The jumps and improvements are no where near what they were in the beginning.

The first couple we would find stupid flaws and make sure to correct them on the next one... only to find a different one the next time. Eventually we hit a point where they were consistent and now the improvements are in the prep and finishing processes making things go smoother overall.

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SHIF
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Location: Wasatch Mountains
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Post by SHIF » Fri Dec 16, 2016 1:08 pm

First pair were way too soft, not worthy of mounting bindings. More of a process test run. They didn't have sidewalls, the core shifted a bit, the top sheet was mis-aligned.
Second pair were way too stiff, not worthy of mounting bindings. Fixed the shifting and alignment issues. Started adding sidewalls to the cores.
Third through fifth pairs were surprisingly good. Only tweaked the core profiles, maintained the composite schedule.
On subsequent skis I experimented with the composites. Adding uni carbon was a huge bonus. Adding biaxial carbon was an epiphany when trying to build a piste carver type ski.
That effort also forced me to start making core rabbits to fit the edge tabs, yields perfectly flat bases requiring minimal grinding for base prep.
Lately I've started to chop the cores off square at the contact points and use full width tip fillers. Used to run the core all the way into the tips and tails, only having a horseshoe of filler material.
Also I've stopped doing full-wrap edges. Now my edges stop well before the ends of the ski. These last two process changes save a lot of time and I think the results are superior too. Full wrap edges on the tails tend to get damaged during handling of the skis, leading to minor delaminations (easily repaired with Superglue and a bench vice).
Now twenty five pairs into this endeavor I think I have my recipe dialed in. My last six pairs are awesome in all respects, and they ski very well. And they have proven very durable, some have over a hundred days use.

-Shif
Last edited by SHIF on Sun Dec 18, 2016 1:42 pm, edited 1 time in total.

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falls
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Location: Wangaratta, Australia

Post by falls » Fri Dec 16, 2016 7:12 pm

The actual layup and pressing after 5 pairs is probably enough for learning to do it well. Then just small improvements every time. Every pair we have made have been skiable (first pair marginal due to soft flex!) without any major defects. I try and improve at least one thing in the process with each new pair.
I think the things you get better at the more you do is edge bending/fit and the actual finishing of the skis. The final product is definitely more polished now at 20+ pairs than at 5 pairs. Just simple things like a nice topsheet bevel that feels round and very smooth in the hand. As well as getting better at predicting core shape/flex on a new model or custom.
Don't wait up, I'm off to kill Summer....

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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi » Sat Dec 17, 2016 2:52 am

I am still a beginner here with 4 pairs of skis, and 2 snowboards (3 rd snowboard layup today .. I hope)
I guess I had an advantage that I have pressed about 30 longboards before my first skis, so that hepls a lot with the layup process and finnishing... But skis and boards are more compley with more room for failure.

I seem to do things in twos at the moment..
first try is a failure, then second try works.

My first skis used a plywood core.. I broke them doing a flex test when they were warm and soft.. so immediately built a second pair with Ash core that were great.
First snowboard the core was a little small so second one was built to fix that and my son used that all last season.
Then I built a pair of skis with a topsheet over veneer and it trapped all the epoxy in making a heavy ugly ski top.. so I had to re-do those without a top sheet...

I hope this board works first time as I don't have much time before Christmas to make a second one.
I am nobody. Nobody's perfect, so I must be perfect.

SleepingAwake
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Joined: Mon Oct 11, 2010 11:06 pm

Post by SleepingAwake » Sat Dec 17, 2016 6:26 am

The first kiteboards I pressed turned out actually quite OK. There where some bumps in the road from time to time. But in general nearly all boards and skis were usable.
Flex was the biggest learning curve and many boards turned out too stiff just because we wanted to play it safe and simply used too much fibers.

Now my projects turn out really well in general as I spend a lot of time planning and calculating and I start to know the little tricks as I work with composites professionally. But with every build you will learn something new and get better with each step.

One point I think is really important is to reflect after the ski is done and think about what to do differently next time. I usually make a word file with all the information about core profile, layup, flex calculations, resin and fiber types, processing parameters and all that stuff. Like that you kinda have to reflect and you can look up all the things I wouldn't remember otherwise.

Cheers, Reto

Jonsn
Posts: 18
Joined: Sat Jan 02, 2016 1:28 pm
Location: Munich & Bregenzerwald/Austria

Post by Jonsn » Thu Jan 19, 2017 3:24 pm

I pressed my first skis by screwing blocks of wood all alond the length of the ski. The skis turned out o.k. and it was an easy method to dive into all steps of skibuildung without caring too much about a press.

After having a vcauum press the results were much better and the skis with bent wooden sidewalls and no full-wrap edges turned out well. I still ski my fourth pair I have built.

I try to set myself new challanges every couple of pairs. I started to focus on lightweight touring skis with semi-cap poured sidewalls and 3D topsheets last season. For this season I started to integrate a CNC mill and laser cutter into the process, which is a challange on its own.

I also spend much more time in designing and trying to predict the skis characteristic and simplify and speed up the whole building process as good as I can.

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