Ski Builders Forum

Found a good deal and bought some I-beam. Happy Monkey design would give me a cavity height of 14 1/2". This seems too high.

I would like to make the cavity big enough to get the job done, but not so big I have to build extra thick molds or fill out the extra space with a shim. I would rather get the cavity height close to start with.

Veteran ski builders, any recommendations?

Cavity will need to hold top and bottom molds, heaters, air hose, cat-track and cassette.

The question seems to come down to the desired thickness of the top and bottom molds and how much space to allow for the air hose to inflate. Insight here would really help.

Better too much then to little. You cant make it bigger but you can always make it smaller.

Yep, too small would be a problem. Trying to avoid an extra 3" of wood in every mold or shoving a stack of mdf in there every time to act as a shim.

I'm thinking somewhere between 10 1/2 and 12 1/2 inches would be the cavity height I would be looking for. Here are the components that put me in that range:

Top and bottom mold: 7 to 9 inches.
1 to 2" from top of lower I beam to bottom of camber (lowest point).
3" of ski tip rise.
2" to transition air hose back to horizontal above ski tip.
1 to 2" minimum thickness of top mold above ski tip hose transition area.

Gap between top and bottom mold: 3 1/2 inches.
1/4" Aluminum skin + bottom heater + aluminum skin.
3/4" Bottom of cassette + laminate stack (skis, uncompressed) + top of cassette.
1/4" Aluminum skin + top heater + 1/8" MDF.
1" Cat-track.
1 1/4" Aluminum skin + air hoses + aluminum skin.

(Maybe it's time I start thinking in metric).

This will be my first rodeo so these are estimates. Real world experience might indicate something different.

What cavity heights have you used and what do you recommend?

Fall Line wrote:Trying to avoid an extra 3" of wood in every mold or shoving a stack of mdf in there every time to act as a shim.

If you put them on the lower part of the press the shims can just stay in there forever, so don't worry about too big cavity height.

bigger opening give a option to make upper mold moving up and down for easy loading the cassette. I have 14 inches opening… if had to do it again I wouldn't go any less

My press has a 10" opening, if I were to do it again....and I will, I will go bigger...probably 14".

Sounds like 14 1/2" will work fine. Keeps things simple.

Thanks fellas.

MM, chrismp, and Mad are all correct. I'm at 14.25 and I would not go any smaller... not even .25". The more space you have to move the cassette in and heat blankets the better. the first time you shove it in there can be quite hard and the more space you have the better. I say make 30-50 skis then reconsider changing the space. Height is always "easily" adjusted; length and width are the ones that are more set in stone. You feel good with those measurements?

Cavity Width: 14 3/4"
Cavity Length: 9' 9"

Width could be a problem for some. I ski pretty narrow. Can always press one at a time if I get a wild hair.

As far as length, I do like longer skis - 190cm to 210cm.

If the press flexes too much, I can Phase II the design and use the extra length to create a moment connection. I think I'll be OK, the beams are pretty beefy.