1. I only have experience building snowboards but there is actually not that much to be gained here. I have build boards where I let ±45° layers pass behind the sidewall to connect the top and bottom laminate, thinking it would increase torsional stiffness. More recently I also included torsion in m...

Timw that was what i was thinking of doing. But can I do this with all the layers? so non of the fabric is going over the edge? maybe an opposite rabbet, so the sidewalls are thicker then te core it self, so there is no gap between the layers That will maybe not give a good bond between the vds tap...

So the flax is only lenghtwise placed UD? Then there is no structural reason to have it overlap with the edge. I suggest cutting the flax to stay between the edges and only have the carbon/kevlar 45s (the only transverse reinforcement) overlap with the edges. You will not need the rabbet anymore. If...

Most of my snowboards end up being 4mm wider than originally intended because I keep forgetting this when I have my templates cut.... . Luckily for snowboards that is not much of an issue.

Afaik setback typically refers to the center of the effective edge length. With full camber skis this used to be identical to running length. Now that running length and effective edge are often not identical anymore, the definition may differ between manufacturers, but I'd guess that effective edge...

I rub my base with a ski wax paste before pressing (if I don't forget). Drawback is that it warps the base upward a bit (because the wax swells the base) and... be careful, stay a bit away from the edges. I remove the epoxy with a paint scraper (the type that you pull) before grinding (also if I did...

For forming the UHMWPE to the shape of the ski I'd suggest first vacuum bagging it dry, and the apply heat to the UHMWPE to form it. Just heating locally along the 20deg bend with a heatgun may already do the trick, better if you have a way to heat to whole thing. Doing it dry will give you plenty o...

For torsion I am now using the paper below, seems to match quite ok for my snowboards. https://www.fpl.fs.usda.gov/documnts/fplrp/fplrp156.pdf I have written a script that calculates the core thickness profile based on a pressure distribution and longitudinal deflection pattern as input. Now adding ...

A small fan heater in a tent over your mould(plastic sheet or something) will easily give you 15 degrees extra. Just make sure nothing that burns can get too close to your heater( so no sawdust or plastic directly against your heater)

It's like this one: https://www.siliconesandmore.com/nl/vacuumpomp-evd-ve115sv.html Cheap and work well. Lowish flow though, but perfect for this job. They'll vaporize a bit of oil if the inlet pressure is not at vacuum yet, so not good for moving a lot of air. If you buy one, get an exhaust filter ...

Yes I did backcoat it.

The supplier gave me a new topsheet for free. Another customer had the same issue with a topsheet printed at the same time. They suspect there was something wrong with the ink.

I'd expect the same would work for skis. I would just do two in parallel and run the supply line also 30cm between the ski ends. IIRC the membrane is Dahltexx® SP-2 from Airtech (they sent me a generous sample for a PhD student's project) Don't know if there are other sources than directly from Airt...

I never had any issues bonding them. Material is PA12, which should bond decently without preparation. But as far as I know the bonding side has been corona treated to further improve bonding.

Are you bonding the right side? The top side has a protective film on it which releases easily......

BTW I just draw circles that I trim, I do not use the radius command

radii.png Maybe this makes it clearer. First draw the center section to where you want it to start and end. Offset it an amount equal to the next radius you want (in the case 1000 & 2000 mm), then draw the next radius with the endpoint of the offset line as centerpoint. (Centerlines indicate th...