Press Design

[Richuk]

Some interesting features:



The cat-track cannot move laterally. Linear activators pre-position the track and assist in ensuring positive pressure is maintained at the tips. We don't need to independently heat the tips, as our ramp rates are slower.

Linear activators are not so expensive, especially when you use bicycle pumps. Inserting springs that resist compression within the pump means they are able to assist in raising and lowering the cat-track. Semi-rigid posts will ensuring the cat-track cannot move laterally or longitudinally. Limiting the amount of resin to the correct value is the final step in ensuring the core, fibre and topsheet remain in position, as 4-6 linear activators will pin the parts in place before the hose is inflated.

[twizzstyle]

Forget the press, those skis are awesome!

Never seen anybody do CNC flash removal and sanding either, that's pretty slick (if not overkill)

[OAC]

Forget the press, those skis are awesome!

Never seen anybody do CNC flash removal and sanding either, that's pretty slick (if not overkill)

That happens when you have money! :-)

[Richuk]

Haha, it's crazy stuff, http://exoticskis.com/exoticskis/home.aspx : see RTC, but not uncommon: (inc water jetting)

[MadRussian]

Some interesting features:



The cat-track cannot move laterally. Linear activators pre-position the track and assist in ensuring positive pressure is maintained at the tips. We don't need to independently heat the tips, as our ramp rates are slower.

Linear activators are not so expensive, especially when you use bicycle pumps. Inserting springs that resist compression within the pump means they are able to assist in raising and lowering the cat-track. Semi-rigid posts will ensuring the cat-track cannot move laterally or longitudinally. Limiting the amount of resin to the correct value is the final step in ensuring the core, fibre and topsheet remain in position, as 4-6 linear activators will pin the parts in place before the hose is inflated.

I liked an idea. Not sure what the story with bicycle pump.
Linear actuators they are on air o just connect them compressor with their own pressure regulator because usually they require no more than 20 PSI.

[Richuk]

Bicycle pump - add an additional spring inside the pump to aid the return (raising) of the cat-track. It would be a balancing act, as would the number of pumps required to maintain the whole cat-track.

[MadRussian]

Bicycle pump - add an additional spring inside the pump to aid the return (raising) of the cat-track. It would be a balancing act, as would the number of pumps required to maintain the whole cat-track.

I see benefits to use this system to pinch cassette in place evenly at the same time.
What you describe to raising the cat trucks sounds too complicated.. btw dual auction cylinders can be used instead of bicycle pump but balancing possibly not going to be simple. You may need whole bunch of air regulators, controllers and such… . Don't take me wrong it looks cool and if you want to do it all power to you.... But in our hobby environment not sure if it necessary
There is a simpler ways of raising the cat trucks

[Richuk]

Dude, it's an idea for those who are considering how to resolve the issue of core shift and or issues with poor tip compliance/excess epoxy at the tip and tail.

I have a variation up and running using a few additional bits and pieces. As pumps are not designed for this purpose, a relief valve should be included.

I don't understand this notion of hobbyist environment/necessary ... the fact that people can rock up, read the forum and build with a solid understanding of what they are doing is the name of the game - where you go from there is up to you. Personally I hope it promotes a little more lateral thinking.

[MadRussian]

for now I have a problem with core shifting. Not sure why. Will do few changes next time around. Maybe even add a couple of those linear actuators will see.

to me hobbyist environment/necessary is volume of production and everything what going with it.
I'll use different example of my thought.
In one at a time pair skis/board biulding heat blankets is not necessary, can be done without. In my personal case I have to because of the shop location in unheated garage. At same time hot water heating/cooling system is not necessary because it designed for large volume production and cost lot more compared to diy silicone blankets/controllers. can I build this kind of system for my press? Yes. Do I need to? No.

[Richuk]

There's a distinction to be made between quality and quantity.

[falls]

1.8kg for a 184cm pow ski! Yikes.

On3p has been using linear rams (pneumatic) in their tips/tails for a few years now. More to help with tip compliance than anything else I think.
I think its a good idea.

I think the idea to have the cat-track constrained to up and down movement is also good. Stopping any sideways movement. You can use simple method of bracket with hole in it and a post and spring to prevent shift and also allow retraction of the cat track. Bit less work than air powered maybe. I have seen it on some presses I think.
In practice my cat track is suspended by bungees laid out identically left and right in terms of position and length so cat track tends to come down evenly. Identical fill rate of bladders is essential too for this.
I do like the idea of linear actuators in the tip/tail to enhance tip conformity and stop the cat track pinching the cassette to the mold before it fully conforms to its shape.

[falls]

http://windells.com/2009/news/windells- ... 2lineride/
Link for you to a Line skis press.

[MontuckyMadman]

8lbs for the pair is a good weight. Depends on dims but at like 156-123-145 and 184cm 4 lbs per skis is fine.

[falls]

I thought it was 1.8kg for the pair? That would be super light.
3.6kg for a pair isn't all that much lighter than the pow skis I have been making that are about 4.2 - 4.4kg a pair.

edit: no you're right it's 1.8kg a ski. 3.6kg a pair. Light sure, but not outrageously light.