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Alex13
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Post by Alex13 »

I'm using the uni's big ass bandsaw and thicknesser to do the cores, then stealing the CNC again for the profiling, shape and insert holes. My 4th yr project is on snowboards, so I can use the uni equipment basically as much as I want as long as it's project related.

I'm using Tasmanian oak insert stringers with Paulownia cores. I don't trust the Paulownia either. Have you put a core together yet in a board? How did it feel with regards to flex etc, and what was the thickness? Mine will be a 7mm centre thickness tapering down to an average of 2mm for the tip and tail on a 157cm board.

I haven't found much info on Paulownia in snowboards. I know Arbor uses it but never as a full core, always as a partial replacement for Poplar.
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falls
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Location: Wangaratta, Australia

Post by falls »

hey alex.
for the wire rope in the cat track go to the hardware store and you will find little screw down toggles that anchor onto the rope. you slip them over the end then position them and tighten the screws to stop them slipping.
It seems pretty common to slip a washer on that sits against your last cattrack piece then a spring whose diameter is less than the washer then another washer and finally the screw down toggle.
Here's a pic at ON3P. I found the toggles at Home Hardware the other day.
No experience on how stiff a spring to use sorry. I have done my cat track with bungee cord and tied it off under some tension to keep the pieces together. So for the spring method I would suggest compressing the springs a little then securing the toggles. Someone might correct me on this.
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MontuckyMadman
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Post by MontuckyMadman »

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MontuckyMadman
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MontuckyMadman
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Alex13
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Post by Alex13 »

Thanks for the info there Tim, useful stuff. I've got a couple of those things here, bought some when I bought the rope. I figured they may come in useful. Now to find some springs...
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MontuckyMadman
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Post by MontuckyMadman »

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falls
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Post by falls »

I just pulled it off their spring production update on the homepage. Some of those pics you linked aren't in the update though. That closeup of the rubber protection for the blankets is interesting - I had been wondering exactly what they did there.
Which brings me to my next point - Alex - with the spring method be careful that the springs cant press on the heat blanket in any way. I read I think the guys from blak sheep (?) wrecked a really expensive blanket by pressing the spring through the silicone.

@montucky: those marks on the sidewall are the reference point for suggested mounting position.
Don't wait up, I'm off to kill Summer....
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chrismp
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Post by chrismp »

Alex13 wrote:I'm using the uni's big ass bandsaw and thicknesser to do the cores, then stealing the CNC again for the profiling, shape and insert holes. My 4th yr project is on snowboards, so I can use the uni equipment basically as much as I want as long as it's project related.

I'm using Tasmanian oak insert stringers with Paulownia cores. I don't trust the Paulownia either. Have you put a core together yet in a board? How did it feel with regards to flex etc, and what was the thickness? Mine will be a 7mm centre thickness tapering down to an average of 2mm for the tip and tail on a 157cm board.

I haven't found much info on Paulownia in snowboards. I know Arbor uses it but never as a full core, always as a partial replacement for Poplar.
hehe, university's great for that kind of stuff. my co-builder's dad is the principal of a high-school and we can use their equipment for free as well (it's closer to our workshop and they have all the big machinesyou could wish for except for a cnc). still, we came across a killer deal for a pretty old monster of a bandsaw (20" sawing height) and we're planning on buying it.

so far we've built one 156cm rocker (think capita flatkick) board with a pauwlonia/beech core. core thickness is 6.2mm tapering down to 2mm. pretty soft if you ask me, but i didn't get a chance to ride it yet.
we used spruce for our previous boards, but it's really hard to come by a nice piece of spruce without any knots, so we went for pauwlonia (which also is a tad cheaper round here).
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MontuckyMadman
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Alex13
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Post by Alex13 »

Finally got the bottom mould finished and did a test press today. I have to fix the mounting of the bungee cord on the far right as it's pulling the cat track apart there, but otherwise worked quite well :)

This is at 50psi. We saw 0.5-1mm deflection of the centre of the upper I beams when relaxing the pressure, which gives an idea of how much force there really is in these things...

Image

Tomorrow's task: Get the aluminium skins in and heaters working, and if there's time do a test layup. Also picking up the unprofiled core for sidewall gluing.
Alex13
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Joined: Wed Dec 09, 2009 12:01 am

Post by Alex13 »

I learnt a valuable lesson too: Try to get the air inlet points closer to the end clamps than I have mine. I had to cut the end of my moulds down as the air hose was getting jammed up against it.
skidesmond
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Post by skidesmond »

Wow, awesome press. It is surprising to the first time builder how much force a pnuematic press can exert. I'm still amazed! Can't believe that a press like yours would deflect at all.

Looking forward to some nice skis coming out of it.
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falls
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Post by falls »

Looks great alex.
Is your bottom mold solid and glued together?
I had a similar trouble with my air inlets to the hoses.
Don't wait up, I'm off to kill Summer....
Alex13
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Joined: Wed Dec 09, 2009 12:01 am

Post by Alex13 »

Yep it's solid and all glued up. I was going to put some supports through it in the form of threaded steel rods, but I don't think it needs it.
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