Our first try.

[Sonny]

Hey everyone, this is my first time posting but i've been lurking around and reading here for months.

Me and my friend started this project this winter and are progressing just fine (I think), we built a ski press and are soon ready to press our first pair of skis. (Made in Sweden! )
I've tried to find answers to all my questions in this forum but there's always more stuff emerging as you try and figure out how to do stuff.

I've got some pictures of our progress and would like tips, do's and don'ts and all the help we can get if there's anything we missed.

When i've been a member for more then a day and made some posts I can show you the images!


What's left for uses to:

# Profile our cores.
# Bend and attach edges to base material. (and build an edge bender)
# Finish our press molds.
# Test the press at working pressure (if there's time)

I've got so much questions and first i'd like to ask what you guys think of my core thickness. I really don't know what to expect but i would like the skis to be soft for powder skiing so i was thinking 2mm at the tip/tail and 10mm underfoot. Unsure about everything in between though.

I would really love all the input I can get and I will get back soon to show any progress and in not to many weeks we will press our first snowboard.

/Sonny

[Sonny]

Forgot to mention that the ski measurements are 160-135-145 @ 195cm running length.

Also I know that almost everyone is using heat in their setups. Is that critical or can you actually make decent skis without extra heat?

Pictures will be uploaded tomorrow, i know this thread is not worth much without them..

[twizzstyle]

The general consensus is that heat is better than no heat, but it really depends on the epoxy you are using. If you are using an epoxy with a room-temperature cure, you are fine.

What are you using for core material? What are you using for composites?

With a ~20oz triax top and bottom, 2-10-2 core profile will be soft (depending on your core material), but great for powder. Those dimensions are awesome, thats a HUGE ski

[deepskis]

Hi Sonny!
I am looking forward to see the pics!

Please let me know if there is anything I can help you out with. I am in Sweden too. Need materials? Contact me!

Cheers!

[Sonny]

We decided measurements and used Snocad-X to print a split template, since we don't have access to a large printer. It was way trickier then we thought to get it straight and perfect!
Here are my skies, i think the measurements are 160-135-145 @ 195cm running length. reversed chamber all the way except 30cm of flat in the middle.



Here are my friends core for his snowboard, he later realized that the outer stripes of oak would be 99% trimmed off, lesson learned until next try.


Here is the press we are building, hopefully it will provide us with enough pressure for our skis and snowboards. Not finished yet, but soon! If are calculations are right we should be getting aprox 15tonnes of pressure @ 4bar, with our two firehoses inflated. I really don't know if that is enough but we'll find out



My friend putting the wire through our steel cat track. We used 30mm square pipes all the way. I now see that people have more narrow pipes towards the tip and tail, do you guys think this will work for us?



Today we started building press molds for our skis and snowboard. This is my friends bottom mold and my top mold (mould how do you spell it?!). They are half finished, 22mm MDF board goes on top of that to get a smooth(we'll see about that) surface.

The general consensus is that heat is better than no heat, but it really depends on the epoxy you are using. If you are using an epoxy with a room-temperature cure, you are fine.

What are you using for core material? What are you using for composites?

With a ~20oz triax top and bottom, 2-10-2 core profile will be soft (depending on your core material), but great for powder. Those dimensions are awesome, thats a HUGE ski

Ok, our epoxy should be fine at 20´C so maybe we are in the clear
and Yes, it's a huge ski, build only for pow so i'd like it soft but not too soft (20oz triax it is)..

Hi Sonny!
I am looking forward to see the pics!

Please let me know if there is anything I can help you out with. I am in Sweden too. Need materials? Contact me!

Cheers!

Thanks yes, any help is greatly appreciated and i've seen your shop All set for materials now but who knows in the future!
[swedish]Roligt med flera svenska byggare om in annat![/swedish]

[gozaimaas]

22mm mdf on top will be too thick in my opinion. I just did the same thing with 16mm mdf and it is borderline too thick. It will average out the profile somewhat due to the fact that it does not want to bend.

[falls]

looking at the large radius on your snowboard mold i think 30mm square cat track pieces will be ok. it is only when the radius gets tight that you get trouble eg. tip of a race ski

[Sonny]

22mm mdf on top will be too thick in my opinion. I just did the same thing with 16mm mdf and it is borderline too thick. It will average out the profile somewhat due to the fact that it does not want to bend.

Oh, yes maybe your right. I've been thinking about how to get the mdf to follow the curve of the profile. My plan was to cut stripes maybe 5cm in width for the flatter middle parts and then make the tip and tails in two bigger pieces and make several cuts from the backside maybe 15-18 mm deep so that it would bend properly. Do you think that could work? Thanks for the input!

[uncski]

Just looking at the press I'm wondering about the vertical tubes that are holding the top from the bottom. Are you concerned about that at all? I'm just curious because I've never seen it done like that.

[Sonny]

Just looking at the press I'm wondering about the vertical tubes that are holding the top from the bottom. Are you concerned about that at all? I'm just curious because I've never seen it done like that.

Hi, no actually those are the least of our concerns, each of those vertical are solid steel and and are good for 18 400kg of force, 73600kg if you count all four. Those two upper beams are only capable of withstanding 30000kg of equally distributed force along the 2,1 meter, deflecting close to 8mm. But we only plan to use half of that force so i hope we are in the clear. Time will tell

[Richuk]

Would a floating central brace would restrict the amount of deflection. Did you include a relief value in the set up?

[twizzstyle]

You might consider filling in the gaps between those supports along the length a little more. Your mold pieces look pretty tall and strong so maybe it will be no issue, but the pressure may be enough to distort the MDF into those gaps, and overtime destroy your mold.

[gozaimaas]

22mm mdf on top will be too thick in my opinion. I just did the same thing with 16mm mdf and it is borderline too thick. It will average out the profile somewhat due to the fact that it does not want to bend.

Oh, yes maybe your right. I've been thinking about how to get the mdf to follow the curve of the profile. My plan was to cut stripes maybe 5cm in width for the flatter middle parts and then make the tip and tails in two bigger pieces and make several cuts from the backside maybe 15-18 mm deep so that it would bend properly. Do you think that could work? Thanks for the input!

That will work but as soon as you cut the mdf you lose all strength in the cut section. My advice would be to use a thinner piece of mdf. The pic below is my test piece using 16mm, it conforms to shape but only just and my camber profile is very smooth as it is a powder board, if it were to have a traditional nose and tail the mdf would have definately snapped. I fixed the mdf sheet down with screws in predrilled holes.

[Sonny]

22mm mdf on top will be too thick in my opinion. I just did the same thing with 16mm mdf and it is borderline too thick. It will average out the profile somewhat due to the fact that it does not want to bend.

Oh, yes maybe your right. I've been thinking about how to get the mdf to follow the curve of the profile. My plan was to cut stripes maybe 5cm in width for the flatter middle parts and then make the tip and tails in two bigger pieces and make several cuts from the backside maybe 15-18 mm deep so that it would bend properly. Do you think that could work? Thanks for the input!

That will work but as soon as you cut the mdf you lose all strength in the cut section. My advice would be to use a thinner piece of mdf. The pic below is my test piece using 16mm, it conforms to shape but only just and my camber profile is very smooth as it is a powder board, if it were to have a traditional nose and tail the mdf would have definately snapped. I fixed the mdf sheet down with screws in predrilled holes.

I'm glad we listend to people at skibuilders.com before we tried this. The MDF idea was scrapped and instead i used two layers of thin plywood. this seems to be working out fine.

Would a floating central brace would restrict the amount of deflection. Did you include a relief value in the set up?

Hi, yes a central brace would probably make the press even stronger but since we really wanted the whole side open, for easy access, we won't we using any other braces. and yes, we have two relief valve to protect us

You might consider filling in the gaps between those supports along the length a little more. Your mold pieces look pretty tall and strong so maybe it will be no issue, but the pressure may be enough to distort the MDF into those gaps, and overtime destroy your mold.

Yes, we have planned from the beginning to put 45mm of wood on top of those supports, both in the bottom and on top. First i thought that maybe even that won't be enough but now I believe that it will be sufficient to keep the mold straight. Do you think this is a good solution? Me and my friend have mixed feelings about using wood in this position, do you think it'll work or do you think it will deflect to much?


My nearly completed mold for my skis


Using the press to attach the top layer to my mold form, i've decided to forget about the MDF and instead i'm now using two layers of 4mm plywood. wich is very easy to bend into the shape of my mold.




Attaching 45mm of wood to the bottom of our press with glue, using our firehouses to apply pressure. (We will also attach 45mm of wood to the top of the press)

[falls]

good call on the 4mm plywood to "skin" your mold with. Much better idea than the 22mm MDF!
Everything is looking pretty good!