super light freetourer

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mammuth
Posts: 442
Joined: Tue Oct 28, 2014 3:48 am
Location: somewhere in the alps

Re: super light freetourer

Post by mammuth »

Tom

sami
Posts: 2
Joined: Sat Apr 25, 2020 11:42 pm

Re: super light freetourer

Post by sami »

SleepingAwake wrote:
Wed Jan 20, 2021 2:39 am
Topsheet is visible carbon

The dimensions are 1850x90 underfoot. And wanted to give Magne traction a go on skis for a long time. it worked well on my snowboard so went for it with this built. The skins are cut to the same wavy shape.

Carbon or Glass UD with biax flax is my go-to layup i have a lot of experience with.

The layup is 500gsm on top, 400gsm on the bottom.

And @pmg: I would advise not using the planar on end grain balsa. If you have a fancy helicoidal cutter you might get away with it, but i wouldn't recommend. Thickness sander would be best, otherwise router sled with template or CNC machining.
Great information and discussion!
Could you elaborate a bit more on your experience with UD Carbon + biax flax? I am right now building a pair with UD flax + triax carbon (the Bcomp data sheet layup, there is another thread on that topic), but already thinking what to try next. I would assume biax flax provides good damping both torsionally and longitudinally, but is this in line with what you got? Did you happen to make any comparisons for using flax either longitudinally or along the -45/45 axis?
BR, Sami

pmg
Posts: 469
Joined: Sat Dec 01, 2012 8:59 am
Location: Sonthofen

Re: super light freetourer

Post by pmg »

SleepingAwake wrote:
Wed Jan 20, 2021 2:39 am

And @pmg: I would advise not using the planar on end grain balsa. If you have a fancy helicoidal cutter you might get away with it, but i wouldn't recommend. Thickness sander would be best, otherwise router sled with template or CNC machining.
Hi,

I used the planer carefully (max 0.5mm ar a time, when core got thinner I further reduced) and did not have a problem. As the planer is the only option I have, I will continue like this though it is quite time-consuming (nearly an hour for planing both cores).

SleepingAwake
Posts: 172
Joined: Mon Oct 11, 2010 11:06 pm
Contact:

Re: super light freetourer

Post by SleepingAwake »

pmg wrote:
Wed Sep 08, 2021 9:05 am
SleepingAwake wrote:
Wed Jan 20, 2021 2:39 am

And @pmg: I would advise not using the planar on end grain balsa. If you have a fancy helicoidal cutter you might get away with it, but i wouldn't recommend. Thickness sander would be best, otherwise router sled with template or CNC machining.
Hi,

I used the planer carefully (max 0.5mm ar a time, when core got thinner I further reduced) and did not have a problem. As the planer is the only option I have, I will continue like this though it is quite time-consuming (nearly an hour for planing both cores).
Good to hear it worked out!
sami wrote:
Wed Sep 01, 2021 1:49 am
SleepingAwake wrote:
Wed Jan 20, 2021 2:39 am
Topsheet is visible carbon

The dimensions are 1850x90 underfoot. And wanted to give Magne traction a go on skis for a long time. it worked well on my snowboard so went for it with this built. The skins are cut to the same wavy shape.

Carbon or Glass UD with biax flax is my go-to layup i have a lot of experience with.

The layup is 500gsm on top, 400gsm on the bottom.

And @pmg: I would advise not using the planar on end grain balsa. If you have a fancy helicoidal cutter you might get away with it, but i wouldn't recommend. Thickness sander would be best, otherwise router sled with template or CNC machining.
Great information and discussion!
Could you elaborate a bit more on your experience with UD Carbon + biax flax? I am right now building a pair with UD flax + triax carbon (the Bcomp data sheet layup, there is another thread on that topic), but already thinking what to try next. I would assume biax flax provides good damping both torsionally and longitudinally, but is this in line with what you got? Did you happen to make any comparisons for using flax either longitudinally or along the -45/45 axis?
BR, Sami
Ride feel is always hard to describe for me. But i don't think torsional damping is a major contributor (or any really). Also, the most effective damping is not along the fiber orientation, and things get incredibly complicated quickly.
Flax has very good stiffness per weight properties, and a ski is designed in stiffness not in strength in the torsional direction. So this is a bit of the sweet spot in a sandwich. A full flax ski will get really calm, so combining ud glass/carbon with biax ampliTex just makes sense to me from a mechanical point of view and my experience with the last builds confirms that in the snow.

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