Give the shape some rocker? Boom, under tension.
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Since the weight is in the center and being supported from the ends of the board (trucks), the bottom will always be the part under tension… It doesn’t matter how you change the shape of the structure.
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I see 2 reasons, lid on bottom needs to be much stronger to support all components, and wants to open instead of close during use. During assembly lid on bottom means all parts needs to be secured upside down firmly to deck or it will fall onto lid, alternatively parts are built onto lid and secured to deck, also annoying. Lid on top means drop parts in, close lid and done.
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I hear you but i disagree. All of the components should be secured to the deck in my opinion and merely supported by the enclosure/ lid.
Lid on top means water ingress and looks stupid. My two cents.
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I’d argue water ingress is easier with lid on bottom?
The seam would be way more exposed to splashback from the wheels.
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Water doesn’t usually travel upwards. It obeys gravity.
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I made a mould for an integrated deck a long time ago. I never made the deck but was considering using something like this in the core.
https://www.ecfibreglasssupplies.co.uk/category/nidaplast
No idea if it was going to be any use.
But capillary action disobeys gravity. I always secured components by sandwiching them between the lid/enclosure and deck with high density foam. Like the battery, can’t really secure it that well, just be sticking tape or whatever to the heatshrink. I always saw the lid or enclosure as a device to apply pressure to all parts so nothing can move. And I think the ESC should be secured to whatever is closest to air for heat, most of the time the bottom of the enclosure/deck facing the ground
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Ahh the good ol capillary action. I hate that guy. But yes it’s a valid point. Kinda moot tho if the components are attached to the deck with closed cell foam as support from the enclosure.
There’s plenty of ways to skin a cat, but if I was skinning this cat, it’s lid would be on the bottom.
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How bout the middle ground, enclosure is molded top and bottom and all components are inserted through the rear like a cassette lol
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You are one sick and twisted motherfucker.
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Man, that stuff will slice and dice your fingers. Use extreme caution. I don’t miss that stuff at all.
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You’re going to see minimal capillary action without a material that readily absorbs water. And if the water around an enclosure seal is slowed enough, the short term splashes most regular riders will see will dry before they become an issue. A bottom mount enclosure should have no issue being reliably splash protected, submersion would be different or long term exposure.
On top, we introduce a seam that traps water and that location is assisted by gravity.
I personally feel like a bottom access enclosure would be better for water.
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Without a vacuum bag you will get voids in the laminate. As far as sandwich panel cores go I would recommend cork. There are two readily-available materials for hex core. Aluminum and nomex. One corrodes when it gets wet and the other disintegrates when it gets wet. Neither are used any more on carrier aircraft because most times a sandwich panel had to be opened for rework there was no core left. Someone mentioned rohacell. That would also be a good choice from a durability point of view. It has another advantage in that it can be heat formed instead of machined - simplifying the production. If you do go with a hex core and need to machine it the trick is to fill the cells with wax first and then melt it out. Otherwise you will get a lot of tears and damaged core.
To add strength forget chicken wire. Use woven Kevlar.
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Practical question about Kevlar, against impacts should it be inner + outer layer (mixed with carbon)?
I’ve read on a boat forum that Kevlar was more useful when inside instead of outside. But what if I want to protect the carbon fiber itself + the core of the part.
Also, how much stress can epoxy withstand when soaked into Kevlar and carbon before breaking?
@Jordicious you can go on the cheap with a fish air pump… Hoses, stretchable wrap or trash plastic bag, gorilla tape, good scissors, and you got a good starter pack.
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@glyphiks currently working on a new design for the lid that will be a good middle ground between top and bottom lid styles…
And no, it’s not the @BluPenguin cassette deck.
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I call suspended top lid 
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Kevlar, more so than fiberglass, is weaker in compression than in tension. Your board not breaking is going to depend more on not getting any delaminations in it when you build it. A layer or two of Kevlar wouldn’t help with that. I wouldn’t bother. Get the correct stiffness for your weight and the board will be strong enough if built correctly.
The strength and stiffness of the laminate is a result of the combination of the matrix and the fiber. The relatively low strength of the resin is already considered. The only property that is dominated by the resin is the interlaminar shear. That is why limiting the size and quantity of the delams is so important.
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I vac-bagged my first enclosure with a Food saver and napkins. I tried the clothes bag method, mixed success. If I do this again I’ll try the vacuum skate deck press, ROAROCKIT
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So, what would be the minimum number of laminations then, with a foam core and 250gsm glass?
I weigh about 70kg for reference.
Btw is the general opinion on drop down vs drop through? (Possibly a controversial topic)
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