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Thank you very much!

Thank you Russ! It really means a lot to hear that from a such a highly experienced expert. I generally try to avoid mentioning horsepower since those new to hovercraft always assume "more" automatically has to be "better". However, I think you'll be amused to hear that the prototype in this video only has 31hp for thrust AND the throttle is hooked up through the factory governor. I have been really amazed by how well the Kawasakis perform. I hope you and your family are doing well!

@@Hoverstream I used to really want those Kawasakis - the build quality is far better than the equivalent Briggs or the horrible Coca Kohlers. Plus it's a much sexier brand name! But they just weren't available in the UK.

It's camera effect - 'Rolling Shutter' I believe it's called, or vibrations from the camera being mounted on the fan assembly. Used to see the same effect on my own.

@@russpullen Thanks - makes sense.

yeah, you can see it in the pilot's body as well.

Russ nailed it. Which is to be expected since he is an expert with hovercraft as well as a professional photographer! I had an older gopro stuck on top of the duct and the minor vibration there makes that weird effect. This is just a hunch, but I also think the gopro is trying to use its algorithm to "stabilize" the motion on the fly and instead makes it worse!

That engine will ultimately be mostly enclosed with a cover over it to prevent direct spray. As for traditional atmospheric venturi icing like on aircraft, I've personally never had it happen on a big EFI engine like this (though I know it is theoretically possible). The only time I have experienced it is on the carbureted single cylinder Briggs lift engines we used on the CP2. Thankfully, it was a rare thing and required a very specific atmospheric conditions. We later modified the air intake as a result. The EVO is using an immensely higher quality twin Kawasaki for lift, and that intake does draw warm air from over the cylinders through a far better airbox design. Time will tell whether that's sufficient, but I don't think it will be a problem.

It would be fun to do so someday, but is not currently planned. Many of our customers are operating on ice at least part of the time and the advantages of a twin engine setup on ice are enormous. Although I personally enjoy single engine integrated machines, they're usefulness is almost entirely recreational. For the majority of our customers, recreation is a side benefit and not their primary goal.

Those are foam core ribs we added to stiffen the flat areas where metal wasn't touching. They are made from a light polyiso foam (I think it was 4lb) we just happened to have on hand from an old project. It's a very easy sanding foam great for this kind of thing, but doesn't do well as a core in real parts. The foam that will melt with solvent is polystyrene like you'd get at the home improvement store.

One of the most difficult challenges with doing this stuff as a small company like us, or especially as an individual, is finding good suppliers. Especially if you want bulky items that require truck shipping; most core materials, for example. The right combination of willing to work with you, not so far away that freight costs are unreasonable, has what you want, AND will sell at a reasonable price... that is tough to find. Unfortunately, the vast majority of composites companies are still stuck in the 1980's. Getting a list of WHAT they sell, let alone a price for it, involves lots of phone calls and middle men, usually with a sales person who isn't too interested in dealing talking to you because your volume isn't high enough. If you can solve that problem, the actual work itself is totally doable (though extremely time consuming).

@@Hoverstream Thank you! That makes sense. How does XPS from home improvement stores compare in price and stability to the modeling foam used in the video?

@@wwindsunrain Massively less. 2" x48"x96" XPS (at least where I am) is way more than it was a few years ago, around $45-50/sheet. We use it for support structure on some plugs underneath the urethane board. XPS comes in various densities but most common is 2lb. 2lb urethane board is roughly double at $110, but honestly 2lb urethane is so soft it's fairly useless. We're using 8lb which is still considered way too soft for what we do but we make it work. Fine for a one-off plug, but you're not going to get multiple pulls very easily. It's roughly $400 a sheet though we got lucky and snagged a clearance price on oddball 1.75" stock. The "real" model board for high definition, high accuracy tooling is 30-50lb density and very pricey. It comes in smaller sheets, but using the 2x48x96 size for comparison it would be in the $1000-2000+ per sheet range. The real question on what you need is how accurate/detailed you want and whether it's being CNC cut or hand shaped. If you wanted to do a 3D profiling operation on a CNC like we have in the video that would be impossible with XPS. Also, with the higher density "real" tooling board, those can be thought of more like you would a sheet of aluminum. They can be highly detailed, extremely durable, and you can directly machine your mold in one step.

Yes, stiffer panels will eliminate most of that. Gel coat has to be hard for scratch resistance and durability, but hard also means the gel is brittle. A fiberglass panel can safely flex much more than the gel coat can tolerate so you eventually get spiderweb cracks. Minimize flex in the panel and you minimize the stress cracks in the gel coat.

Thanks Russ! 👍