Moulds for 3D base design
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
As for wide airbags I was able to find three options. Two of them are known to work, but quite expensive and the other one is just a theory of mine that might work.
First option would be buying a cutom made bladder by ATL which costs around 2000 USD. Too expensive for me.
Second option would be buying a wide hose made by a German company. The hose is called Hilcoflex 356 (14" diameter) and 3m cost about 900 USD. Still quite expensive.
The third option I was thinking about is using an inner tube for a tractor. There are models that are large enough to fit a press. This would only cost about 50 USD. Inner tubes are made of a rubber that withstands up to 130°C, so that's not a concern. However, I'm not sure about how the inner tube would behave inside a press frame. I.e. will it just bulge out on the sides of the press and exert very little force onto the laminate? Is so, are there any feasible methods to fully contain the inner tube inside the press?
First option would be buying a cutom made bladder by ATL which costs around 2000 USD. Too expensive for me.
Second option would be buying a wide hose made by a German company. The hose is called Hilcoflex 356 (14" diameter) and 3m cost about 900 USD. Still quite expensive.
The third option I was thinking about is using an inner tube for a tractor. There are models that are large enough to fit a press. This would only cost about 50 USD. Inner tubes are made of a rubber that withstands up to 130°C, so that's not a concern. However, I'm not sure about how the inner tube would behave inside a press frame. I.e. will it just bulge out on the sides of the press and exert very little force onto the laminate? Is so, are there any feasible methods to fully contain the inner tube inside the press?
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
Sounds like making both base and top mold from cnced wood casseetes would be cheapest and easiest. Covered in plastic. Skin it with al above and below. Ur talkin about very little shape if u want to spoon tip and tail. You will have to cnc 3d the core anyway.
Use masonite or thin mdf.
Use masonite or thin mdf.
sammer wrote: I'm still a tang on top guy.
An inner tube will, indeed, simply bulge out of the frame. However, all you need it to do is to be the airtight part of a pressure vessel; it would seem to me to be relatively trivial to make a fabric sleeve to hold it in shape. I hypothesise, in fact, that you may not even need to sew such a sleeve - by wrapping the tube a few times, friction between layers might well be enough to hold it all together (and the press itself should stop it unravelling).chrismp wrote:However, I'm not sure about how the inner tube would behave inside a press frame. I.e. will it just bulge out on the sides of the press and exert very little force onto the laminate? Is so, are there any feasible methods to fully contain the inner tube inside the press?
What about a slice of thick (4-5 cm) of semi-hard rubber inbetween cattrack and ski/board. maybe with a slice of HDF inbetween to even out the pressure. I got a sample of some for another project that I think could work. If you press your finger into it as hard as you can you can depress it about a cm. Softer than "normal" rubber but still hard. It should comform around a 3d shape i think.
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NinetyFour
- Posts: 66
- Joined: Fri Jun 01, 2012 5:54 pm
<iframe src="//player.vimeo.com/video/36665133" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href=" Skis: LAB POW 01</a> from <a href="http://vimeo.com/freeskibrands">Freeski Brands Productions</a> on <a href="https://vimeo.com">Vimeo</a>.</p>
<iframe width="560" height="315" src="//www.youtube.com/embed/6trW0411v4c" frameborder="0" allowfullscreen></iframe>
Here's some enlightenment on Surface's take on shaped bases. The core is flat across the top and the convexity is milled into the bottom of the core. How they're milling it then pressing it though, who knows...
I wonder if a guy could CNC a bottom ribbed style mold with two sides dished identically, but the dishes were exaggerated in their width and depth, so if you weren't perfectly aligned then skis would still press just fine. Plus, you could always build with templates of different widths to experiment with ski shape, the rocker camber and dish profile are the only things you couldn't change. As long as you CNC'd the bottom of your core with the same profile that's in the mold, then it would likely work just fine. You would be limited to a nice smooth shape like the Lab 001's here though, no fancy cleats like the DPS spoon.
That probably makes zero sense in words so I'll see if I can transform my thoughts into an AutoCAD drawing...
Edit: It's late and I'm not sure how to embed on here... I'll fix it within the next few days.
<iframe width="560" height="315" src="//www.youtube.com/embed/6trW0411v4c" frameborder="0" allowfullscreen></iframe>
Here's some enlightenment on Surface's take on shaped bases. The core is flat across the top and the convexity is milled into the bottom of the core. How they're milling it then pressing it though, who knows...
I wonder if a guy could CNC a bottom ribbed style mold with two sides dished identically, but the dishes were exaggerated in their width and depth, so if you weren't perfectly aligned then skis would still press just fine. Plus, you could always build with templates of different widths to experiment with ski shape, the rocker camber and dish profile are the only things you couldn't change. As long as you CNC'd the bottom of your core with the same profile that's in the mold, then it would likely work just fine. You would be limited to a nice smooth shape like the Lab 001's here though, no fancy cleats like the DPS spoon.
That probably makes zero sense in words so I'll see if I can transform my thoughts into an AutoCAD drawing...
Edit: It's late and I'm not sure how to embed on here... I'll fix it within the next few days.
Are you sure you need to change the mould? I would have thought an initial prototype could be produced by controlling the heat being applied and cooling of the final product.
A wood core can be pre-shaped to approximate the final shape when it is dried before use - apply heat from above. Book matched cores seem best option. Vary the wood species to adjust the initial results ... they need to remain able to orientate over the base material and the binding area needs to remain flat. The exact moisture content of the core is important, but could be overlooked in this instance. Bringing just the top section of the core down to the required 6 - 7% should be fine. This isn't imagined, it happens if you heat from above only when drying your cores. I would do this to de-stress the wood ... although not so much so that the core fractures during initial stages of the pressing.
Using quadaxial glass on the top, tri-axial on the bottom should give the desired end result. I wouldn't mess around with the cure cycle at this stage. How the skis are cooled is an easier way to tweak the final result, it should be possible to emphasis the effect of the choosen fabrics this way. If you are not using a 3D cassette, it might be advantageous to cool within the press - backing off the pressure and creating a uniform gap, allowing the top laminate to cool at a quicker rate than the lower. It's not the most commercial option. Alternatively, assuming the temperature of the workshop is around room temp, remove when the skis are hot, hot, hot and allow to cool in a hot box. The box would need be to use a programmable timer so that you can go from hot to cold at a controlled rate. Open air cooling would be OK on a trial basis, provided its room temperature. The end results would vary unless the temperature of the workshop is kept constant - this approach is a bit technically rough and ready though. If the results provided by cooling are too shallow, look again that fabric - add wieght on the 90 degree axis, before looking at the cure cycle or the relative temperatures between top and bottom heater.
The downside of this approach is the unusual stress and strain ...
A wood core can be pre-shaped to approximate the final shape when it is dried before use - apply heat from above. Book matched cores seem best option. Vary the wood species to adjust the initial results ... they need to remain able to orientate over the base material and the binding area needs to remain flat. The exact moisture content of the core is important, but could be overlooked in this instance. Bringing just the top section of the core down to the required 6 - 7% should be fine. This isn't imagined, it happens if you heat from above only when drying your cores. I would do this to de-stress the wood ... although not so much so that the core fractures during initial stages of the pressing.
Using quadaxial glass on the top, tri-axial on the bottom should give the desired end result. I wouldn't mess around with the cure cycle at this stage. How the skis are cooled is an easier way to tweak the final result, it should be possible to emphasis the effect of the choosen fabrics this way. If you are not using a 3D cassette, it might be advantageous to cool within the press - backing off the pressure and creating a uniform gap, allowing the top laminate to cool at a quicker rate than the lower. It's not the most commercial option. Alternatively, assuming the temperature of the workshop is around room temp, remove when the skis are hot, hot, hot and allow to cool in a hot box. The box would need be to use a programmable timer so that you can go from hot to cold at a controlled rate. Open air cooling would be OK on a trial basis, provided its room temperature. The end results would vary unless the temperature of the workshop is kept constant - this approach is a bit technically rough and ready though. If the results provided by cooling are too shallow, look again that fabric - add wieght on the 90 degree axis, before looking at the cure cycle or the relative temperatures between top and bottom heater.
The downside of this approach is the unusual stress and strain ...