Ski Builders Forum

I'm getting ahead of myself her, but if anyone has any knowledge to share it would be appreciated. I need to know what I should allow for expansion, lengthwise? I'm about to trim it by the width of the tip plus 0.75 mm. I'm keeping the width tight, so I can load the edges - part of me thinks I should only keep it tight underfoot and then let the tension out and match the 0.75 mm. Is this right?

Making changes to the outline idea below is not a problem. I can pick up a few more bits from the scrap-yard if I need to. As you can see from the photo's just keeping it pretty simple. The tips (aluminium) are 2 mm, so the tip spacers can sit back on to the end of the pieces being used to retain the ends (3.5mm) - like a buffer. I will be adding a stop at the end of the tip to keep the tip spacer in place.

PM if you need more info - I will probably press at 80 degrees C at around 50 psi.

ANY help will be much appreciated!





Btw - I believe I have searched the forum, but if you know of a post that I have missed

how are you planning to cut the AL?

Create a form then mill it - PM sent.

You'll be bringing some heat at 80C and 50psi....keep those surfaces clean!

Yeah thanks for the info. You will definitely want a industrial mold release for a cassette.

The aluminium sheet has a mirrored surface and will be making sure the edges to the cassette are just as polished - thks.

Richuk wrote:The aluminium sheet has a mirrored surface and will be making sure the edges to the cassette are just as polished - thks.

Doesn't matter. You must use mold release or the epoxy will be a nightmare to get off of there.

Trust me, I have cleaned epoxy off of cassettes thousands of times. It sucks.

polished, clean, in addition to professional mold release

I'm thinking of setting the edge of the cassette to 89 degrees, maybe a peel layer of some sort will help?

This idea has been bouncing around my head for a while, but I don't really have the time right now. I might need to draw something out, but for the time-being, I hope this outline will do.

The goal is this - super tight edges without the need for glue, but with a bit more flexibility. I think it would be more applicable to 3/4 wrap and would make for a 'one stop' cassette perhaps?



I probably need to mock something up, but imagine sheet of AL, cut to size and ready to be used as a cassette. Add two lengths of AL strips (25 mm x 3 mm), fixed along the two longest edge of the cassette base. Each strip would be around the length of the edge set - these edges would act like a retaining wall for the ply. During layup, the ply is added into the cassette and become part of the flash. The ply would be shaped as per the photo and would create the same result.





The addition of the ply make the ski shaped cassette and because it is ply, (1) you can cut to exact size, as it will give a little and still pull from the cassette quite easily (2) allow different skis to be drawn from the same cassette (3) 3mm ply could be easily milled so that it held the core in place.



Unfortunately, the ply would become part of the flash - which is wasteful.

Anyone think this would work?

Ricuk, impresive work as always
is that ply runing around the tip and tail too?

Yes - 2mm, so it does get caught by the planner. I will extended the core to include tip spacers soon. The idea is just a variation of what I saw in the Blossom video. Although I have SHIF to thank - his whole setup looks really sharp.

I have thought about whether ply could be used to retain a full wrap, I'm not to keen to waste the material. by making it part of the flash. I can see this being a good solution for 3/4 wrap. The other reason for limiting the use is that a full wrap within a cassette means bending 3D edges and its tricky when party done by hand

Richuk, in the last picture, the dark strip to the left of the edge is just a gap and shadow? or there s something after the washer, i cant see it clear

did you find what allowance for expansion you need?

Hi fa, the shadow is the channel rebated out of the AL strip to allow for positioning of the core. I tried to do you a quick drawing ... Ctrl +, to zoom in : )

The gap appears to be 0.4 mm or less, or 0.8 in total. There is potential for variation depending on the thickness of the base material. So far I've used 1.2 and 1.3mm. If I was doing it again, I wouldn't be afraid of 0.3 mm.

I'm using this mold release http://polyfibre.co.uk/index.php?sec=prod&prod=27, this was the other choice http://polyfibre.co.uk/index.php?sec=prod&prod=212

Saw your base grind post - great graphics!

got it now,
thanks for the numbers!
and for the "quick dwg" too, very usefull indeed