Twizz 2012/2013

FigmentOriginal · Post by **FigmentOriginal** » Tue Sep 24, 2013 11:20 am

Getting back to the hollow core ski idea...

Rossignol's new ski the 'Squad 7' has lightened tips...

How do you think they manage that?

skidesmond · Post by **skidesmond** » Tue Sep 24, 2013 4:35 pm

FigmentOriginal wrote:So lets open up the honeycomb core idea discussion again...

How did I miss this?? Are those alpine or nordic skis? They look narrow. And looks like it's cardboard honey comb. Any more details on the ski?

As for the new Rossi honey comb tips... gimmicky looking to me.

OAC · Post by **OAC** » Tue Sep 24, 2013 11:46 pm

Brian May? The Queen guitarist??

vinman · Post by **vinman** » Wed Sep 25, 2013 3:12 am

The see thru thing is not new Burton did that on a few models several years ago. I think they were using aluminum honeycomb....

Not sure how that is done. Yes gimmicky.

FigmentOriginal · Post by **FigmentOriginal** » Wed Sep 25, 2013 3:52 am

Thats a busted cross country ski with the what looks to be cardboard core. I doubt Burton and these new Rossis have breathable membranes or purge valves, so how do they get away with hollow skis?

SleepingAwake · Post by **SleepingAwake** » Thu Sep 26, 2013 12:38 pm

Pressure difference shouldn't be an issue with a honeycomb core, because the cellules are pretty small. But the rossignol is just a marketing thing I guess. How much weight can you possibly safe by replacing some square inches of the core by a pretty heavy polypropylene honeycomb? And if there is a little too much resin in the prepreg they end up probably at the same weight as if they would use any other core...

SleepingAwake · Post by **SleepingAwake** » Thu Sep 26, 2013 12:38 pm

Pressure difference shouldn't be an issue with a honeycomb core, because the cellules are pretty small. But the rossignol is just a marketing thing I guess. How much weight can you possibly safe by replacing some square inches of the core by a pretty heavy polypropylene honeycomb? And if there is a little too much resin in the prepreg they end up probably at the same weight as if they would use any other core...

ben_mtl · Post by **ben_mtl** » Mon Oct 21, 2013 3:07 pm

Hey Twizz,

not sure if I should post here or on the newer thread but since the subject has been talked about in the previous page...
I have a couple questions regarding your drag knife / die-cut bases.

- I'm looking at some drill blank to try and make a drag knife. Locally I was only able to find some 1/4 drill rod, 3ft long and it is some "W1 or O1 type steel". It's more expensive than McMaster at $7/3ft but McMaster won't ship to me anyways... Not sure it's the right stuff though since this steel grade is supposed to be water or oil hardened (I won't be able to make a heat treatment at home...)... any input on that ?

- When you do a die-cut base, what do you use to hold the different pieces together ? Meditape ? Isn't there any problem when you have a "separation line" that crosses an edge ? Any detailed info on that would be great !

Thanks !

twizzstyle · Post by **twizzstyle** » Mon Oct 21, 2013 7:42 pm

Not sure about the rod material... the blanks I got from mcmaster are solid carbide, I thought. This issue with McMaster not shipping to canada seems to come up a lot. Is there no other industrial supply place in canada that might stock something like this?

I'm trying to find the exact thing I ordered from McMaster, but I've got a lot of McMaster emails to go through

I remember it only being a few dollars for a 1/8" rod, 2-3" long. I could easily order a few and then mail it to you.

I've only done a base once that had multiple colors (the foam core skis with the maps on top, bottoms are orange with STUMPYSTICKS in yellow). I did use medipore tape to hold it all together (a lot of it...).

What I did was cut out all the letters first and assemble it as one big sheet, and taped it up with the medipore. Then I cut out the base shapes. It held together reasonably well, and once I had the edges glued on it was pretty solid. I'll never do that many shapes again though, that was a lot of work.

I just drag-knived the bases for my new skis a few days ago, and man... for such a quick hand-grown tool, it does amazing work!

I've done a little experimenting to try to get a good "blade" shape so it cuts clean, but still casters properly. Works great for me, and just putting the blade in the router spindle works great.

ben_mtl · Post by **ben_mtl** » Tue Oct 22, 2013 4:06 am

Nice ! thank you.
After some search on McMaster I believe this (http://www.mcmaster.com/#3009a127/=p1nk2e) is what you might have ordered from them, which is not what I can source locally... I'll look into it.
You made your drag knife from some 1/8" rod ? my smallest chunk on the router is 1/4" so I'll go with 1/4".

...I'm wondering if I could just take a 1/4" drill bit, cut the "flutes" part and make the tool from that... would be easier to source a drill bit than a drill blank !

falls · Post by **falls** » Tue Oct 22, 2013 5:04 am

http://www.canadacarbide.com/products.html

ben_mtl · Post by **ben_mtl** » Tue Oct 22, 2013 5:28 am

yep, I already sent them an e-mail to see what they have, no answer yet.
All the companies that would have what I need are very expensive + they request a 100$ minumum order (the ones I found on the internet and got answers from, at least...)

I'm really digging the drill bit repurpose though...

twizzstyle · Post by **twizzstyle** » Tue Oct 22, 2013 7:21 am

Ah, that is another consideration, you can only go as small as your smallest chuck!

What kind of router do you have? I have a Porter Cable and got a collet kit, so I have a 1/8" collet.

http://buildyourcnc.com/item/router-col ... collet-kit

And yeah, grinding down a 1/4" drill bit should work fine! You just need to get the shape right, so the blade is small, positioned right for good castering, and... SHARP!

My best cartoon of what it might look like on a 1/4" bit:

twizzstyle · Post by **twizzstyle** » Tue Oct 22, 2013 7:23 am

Also - once you do have a good blade made, remember you want as little of it sticking out of the chuck as possible. I was working fast once and didn't think of this, and had about 1" sticking out, and it snapped on the first cut.

ben_mtl · Post by **ben_mtl** » Tue Oct 22, 2013 8:34 am

I have an Hitachi M12VC router... I guess I'm about to pull the trigger on a collet kit, It's gonna help with a (very small) runout problem I have with the factory collet... being able to put a 1/8" bit / DIY drag knife just make the decision easier to take...

It looks like precisebits (where I take the collet kit) also sells "calibration blanks", which might well be useful to shape a drag knife... I'll ask for the alloy type and hardness.

I like to think this "compulsive buys" are some kind if investment... yeah right ! nothing in skibuilding is an investment.. it's just a money pit.
..and CNC building is even worse :p

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Twizz 2012/2013