Ski Builders Forum

Hey guys,

I ve seen a couple of videos/pics where they (it seems to be so) use a fully adjustable bottom mold in a press. These are the videos:

www.youtube.com/watch?v=GUWvdTMjr6I
at 1:15

A similar construction seems to be used at Burtons
www.youtube.com/watch?v=546v1-rLftE
at 2:28.

A different approach can be found at Sisco Sports
www.snowboard-ski-sisco.com/sisco-sport ... pment.html
(scroll to the picture with the yellow press)

and again at Indigo Snow
www.indigosnow.de/manufactory/

This would be just awesome to have just think of prototyping etc. Any thoughts on the constructions above? Has anyone ever thought of building something similar?

Cheers

**Deleted**
Links are now in the post above.

a company called langzauner makes them. I don't doubt they cost thousands.
Otherwise fabricating yourself using a sheet of steel that can be bent to shape but will not be forced out of shape by the pressures of pressing. And worm drives/jacks that you adjust.
doughboy had a version using carriage bolts that he would adjust but it seemed time consuming and maybe hard to get really accurate

Langzauner presses start at 120,000€ for the manually adjustable press, 180,000€ for the automatic CNC adjustable press. I fully designed my own version of a manually adjustable Langzauner, but before I started building the press I built a autoclave instead. The autoclave also has a fully adjustable layup tool. Maybe someday I'll dust off the plans and get to welding up the press.

sounds like a project, any interest in sharing the plans?

in order to compute the thickness of the steelplate and the distance of the jacks in a langzauner type mold: what would you consider to be an acceptable amount of deflection in between the jacks? in other words what amount can be cleared up in the finishing process to get a dead flat base?

cheers

Minga wrote:in order to compute the thickness of the steelplate and the distance of the jacks in a langzauner type mold: what would you consider to be an acceptable amount of deflection in between the jacks? in other words what amount can be cleared up in the finishing process to get a dead flat base?

cheers

Nothing, it has to be flat especially front to back or it will end up bumpy even after a base grind.

I understand. But if you look at the langzauner mold where you form the camber out of ribs you always get a deflection of steel sheet on top in between the support jacks. The only thing one can do is to minimize it by using a thicker sheet/decrease the distance of the ribs until its not detecable anymore for all pratical purposes. For example, I roughly computed the deflection of a 5mm steel sheet supported by ribs 9cm apart and got a max deflection ~0.1mm in the middle of the ribs. So the question is from what amount of deflection on it just doesnt make any sense to go for further improvement? In my example above, is 0.1mm ok/too much/or I can even allow a bit more? What do you guys think?

5mm plate supported with a 9cm gap?
I would be very surprised if that only flexes 0.1mm. I could easily push 5mm plate 0.5 with one finger on it, but funny things happen in a press.

I would do a simple test of some ribs with a plate over it and measure the deflection before I started making such a big endeavor. I think you'll be looking for at least 8mm plate.

yeah, i'd do some testing for sure and it was a quick and dirty calculation to get a feeling for it but i guess it s not too far off. the force on a square cm isnt that huge. but the question remains. what amount of deflection should one aim for at least?

@rnordell: what kind of jacks did you plan to use in your mold?

My design has the top of the press open like the clam shell style presses. This was to be done with an air/hydraulic piston that is normally used in engine hoist. The gap on the hinge side is able to be adjusted with an eccentric cam (like what you see on a sheet metal brake). The bottom platten is adjusted with pillars every 10cm. The pillars have a series of internal inclined ramps allowing the heights to be independently adjusted. The platten is to be a weldment, 3 layers 3/16" thick, with a heating channel cut into the middle layer allowing heated oil or ethylene glycol to be pumped through. The cat track is also internally heated. I think there are photos on this site showing other heated cat tracks.

My crystal ball shows a big investment, bound to have lots of dramas, probably end up never being happy with it and scrapping it for a proven design.

Probably no more investment or drama than a 11'6" x 18", 2300 lb autoclave. Yes, the press as designed was going to cost around $11,000 in materials, but when you are accustomed to designing and certifying modifications on multi million dollar airplanes you tend to take that mentality into everything you do

you could look at chrismp's lower tech solution with vertical pieces of MDF of varying heights every few centimetres.

rnordell wrote: when you are accustomed to designing and certifying modifications on multi million dollar airplanes you tend to take that mentality into everything you do

You didn't even need to say it.