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A snowboard/ski press with non flat bottom (in width)
Posted: Tue Nov 15, 2011 12:07 pm
by mikic1
Hi all,
I am considering to build a ski/snowboard press, but would like it to be usable for doing kiteboards as well. Typically kiteboards have not flat bottom in width, usually it is concave (the maximum concavity can be ranging from few mm to 20mm+). I know my question might be a bit misplaced, but i like this forum quite a lot and will post anyways

.
I do not plan to profile the core with any machine to get it concave, rather the mold will bend it to concave shape. This way core will preserve the strength. So the top part of the board will be following the concave curve of the bottom.
My question is regarding a way make sure the pressure (from inflated hoses) is applied all of the board equally. I can imagine that the steel cat tracks will not bend with the width curvature of the board, so is there any other method to transfer the pressure to the object making the pressure equally distributed over the object, even if the object is slightly curved. I have seen some use wood cat tracks...?
cheers,
Miki
Posted: Tue Nov 15, 2011 12:23 pm
by Jibber
In my opinion vacuum is the way to go unless you can cnc cut 3D molds.
Cheers, Christoph
Posted: Tue Nov 15, 2011 12:33 pm
by mikic1
Thanks for the reply,
I have been considering vacuum, and both vacuum and pneumatic pressing has their advantages and disadvantages, i am really keen on building a press due to several reasons, so any other ways around to do it with a ski/snowboard press?
cheers
Posted: Tue Nov 15, 2011 7:23 pm
by falls
get a really wide bladder so it covers the whole layup at once.
you can find these large bladders
there are companies that make them, but when i looked into it they were pretty expensive.
http://www.atlinc.com/inflatables.html
Posted: Wed Nov 16, 2011 5:51 am
by mikic1
cool, i will def. look into it! thanks!
Another option i was considering is using 3 (around 7'' diameter) closely spaced bladders, as some of the presses i have seen in here, and between the bladders and the board (the kiteboard in my case) place a conformal sheet of say aluminum or perhaps even build a sheet of laminated carbon fiber layers, or glass, so it is stiff enough to spread the pressure somewhat equally from the bladders to the board, but flexible enough to conform to the mold. would this work or am i dreaming

?
Anybody in here has some experience on what would go wrong and if pressing at high psi (50 or 60) would mean that the relative pressure differences seen by the board are irrelevant due to the high absolute pressure?
Cheers,
Miki
Posted: Sun Nov 27, 2011 3:56 am
by Xenia
falls wrote:get a really wide bladder so it covers the whole layup at once.
you can find these large bladders
there are companies that make them, but when i looked into it they were pretty expensive.
http://www.atlinc.com/inflatables.html
Nothing that a lottery win wouldn't put right! Has anyone had any success with pressing straight without using a track or top cassette? My concern having a bladder made specifically is high probability of damaging it. I am sure the company mentioned would have solutions just wondered if there was a low tech way of protecting the bladder from resin spill or being burnt from the heat blanket?
Posted: Sun Nov 27, 2011 4:36 am
by Richuk
Xenia, I'd suggest you give this a read:
viewtopic.php?t=1542&start=0
A lot of people start there research by reading the first journal and work there way forward through the series - it gives an insight into the nuts and bolts of each issue.
Mikic, you're probably reading this thread with interest
viewtopic.php?t=3320. A.badner used hockey sticks instead of AL for his cat-track - which I assume offer a certain amount of flex. Some 'put-up'/temporary beds use laminated ply to form the bed base. They are concaved in shape. You might just need to put a stop a long the edge to stop the bladder exiting the press.
If something like this doesn't work, you'll probably looking at some kind of clam shell design base on the above thread
Posted: Sun Nov 27, 2011 5:12 am
by vinman
A.badner probably got the hockey stick idea from me. My cat track is made of broken hockey sticks that I got for free from about 4 rinks in my area. It really works pretty well. If I could do it over is drill them with a press. My hand drilling resulted in some inconsistency in how the track sits leaving some mild waviness. To combat this I use a sheet of Masonite and a layer of thin rubber over the heat blanket and aluminum. All of these layers now minimize the waves.
The other thing to do would be to flat sand the track. But I'm not sure how well some of the fiberglass laminated sticks would do with this.
Posted: Sun Nov 27, 2011 6:04 am
by chrismp
does anyone of you guys know how the big players (elan) press boards like the ones by bataleon with the triple base?
Posted: Sun Nov 27, 2011 11:43 am
by mikic1
Appreciate the feedback guys! SO much good stuff on this forum.
Due to the diversity I would like in my press (snowboard, ski, kiteboards) I will probably invest in the wide bladder.
Then the rest (heat protection etc.) will be trail and error as always

. I am sure there will be a lot of failure and learning, but lets see. Will probably post pictures and ask for help once I get started (in few weeks)

. Looking forward to it !
Cheers
Posted: Mon Nov 28, 2011 11:57 am
by Xenia
Richuk wrote:Xenia, I'd suggest you give this a read:
viewtopic.php?t=1542&start=0
A lot of people start there research by reading the first journal and work there way forward through the series - i gives an insight into the nuts and bolts of each issue.
Hi Richuk, thanks for the suggested reading, I am doing loads! My problem is I do not always bookmark when perhaps I should. What spurred my question was I had seen the link to atlinc.com before and comments about it. Cannot seem find the topic again unfortunately, its not in your link nor can I find it within search.