Rotax Engines

This sounds like an episode of Junkyard Wars (aka Scrapheap Challenge). I wish you the best in trying to make a hovercraft with only a 2.5 horsepower motor. That's less power than what Briggs & Stratton claim for my lawnmower. The Rotax engines I looked saw on the web are much larger than my lawnmower engine. So I suspect you have much more power available than just 2.5 horsepower.

A hovercraft can be a very difficult machine to control. Please be careful.

Google to BRP Rotax, 4 strokes and 2 srokes engines. The 2,5 hp outboard is for failed main engines event or short distance dingy runs , i have a 2 strokes 20 hp but it will take a chunk out of the payload available. But the 20 hp outboard pushes well my existing dingy. I am thinking about using fins as dagger boards and rudder also. At slow speeds in very shallow wet areas, even on sand, i am considering slim or fat light low pressure tires.

For hoverflying mode, this is in a medium term project, the ground effect is a hazardeous phenomenom, weather forecast is to marine what location is to realestate. In our kiting experiences, security is allways at the forefront. We have some chills at times, but it is part of the fun, as long as one stays in control. A car may seem easy and safe, but ... yes we get used to it, texting, phoning, etc.

i'll see what comments come up from people that have tried the Rotax vs others.

Thanks

Having done both catamarans and hovercraft (18bhp Briggs&Stratton boxer) I wish you luck. There are a LOT of evil characteristics of both. Central hull clearance is paramount, often dismissed until the first square chop is sailed through. The plow-in, where the hovercraft loses lift while moving forward, will rip the propulsion engine right off its mounts. There's a reason the Army gave up on personal hovercrafts: slit trenches. Lose the lift = plow in. Worse on water when the skirt hooks the water. Damn square chop again. Catamarans in shallow water don't point too well. You need rotating airfoil mast because the lateral lift to drag ratio is hard to square with ease of driving and weight/displacement/draft issues. Dagger boards dig in, leeboards rip off, lightweight hulls don't do local stresses well. Poptops are fun in heavy storms, and ALL boats have to be able to handle heavy storms.

Yes you summarised well alot of the contraints for cats and hovercrafts.

This is why each program is paramount to the succes of such endeavor. Often i see such low clearance under cats it makes me mad. In this thred i wanted to discuss primarely the engine aspect of the internal engine Rotax.

Volvo IPS system is an option especially with the reliability of diesel, but the option is fading out for many reasons. Could make a come back though. It's really seperating the salesman pitch with a good clean scientific comparison. For one thing only, if the pod would be twin prop with an outboard vertical lift possibility it would gain points.

$ purchase and $ maintenance (availability) (we are in BRP heaven) . In other words, if the trusted repair guy on your island is an Evinrude for example, you probably allow more points for that.

As for hovercraft, it is a debate untill it is a choice. I fly kites and pretty much gave up waiting lines at the 15 mins away ski resorts, more risky business but we chose it, i am a chicken though when it comes to jumping above iced lake ...

Got to go.

Thanks for your inputs , a little seemingly not important argument can make a difference.

You have write vividly about your dingy, but without saying anything! You must be a salesman by profession as those guys always do that. Did you already built your mother ship? so you only need to add the dingy? Or you are one of those who read something about hover and wants to combine it with ... mother ship that is not the "Enterprise capt Kirk?

Actually the dingy need some kind of power to fly, but the power can come out from.. what? 2Hp engine that you have? or the cable connected to your "Enterprise"? What would be the range of navigation of your dingy? and paddles to do what? flipping air like birds do?

Did you described a concept and calculation of needed air cushion under the dingy? Did you think about how much air has to be pumped to compensate air leaks from the air cushion? What would be the thickness of air cushion to move over 10 feet waves?

Are you a kid or just a s...disturber?

We have to be kids in our mind to develop new products. I am designing my "mothership" but we , architects, like to know what and where things will be located.

I still have my dingy it is a 1994, so a bit old, but the 2,5 and the 20 hp outboards work well, they are 2 strokes , but i keep them just in case and i don't want to buy a new outboard engine just in case. I considered the Torquedos and will keep an eye on them. I plan to build a new dingy and i like the idea of a flying hovercraft, for many reasons. The area where the "mother cat" will be mostly located is (both summer and winter) somewhat hazardeous because of tidal effects, but we are used to that, and as you probably know, it leaves large strands and we don't want to be stranded in shallow waters surrounded by rocks, sand, algeas, etc. in one area we like to go the strand is almost a mile wide at low tide and about 40 miles long both sides of the river. But such strands are perfect spots for fishing, flat water surfkiting , canoeing, kayaking, swimimg, and more. We use the ATV 4 wd vehicles for going places but the GVT is not thrilled about it, marine life neither, so the hovercraft looks like a good idea. In Cayo Guillermo, a paradise for surfkiting, one had a dingy with a deltaplane above it, you can see it on youtube, he flew this thing 1000 feet in the air ... he crashed it and people died (from rumors) , so i prefer hovering and low flying with ground effect. Great strand there too, different blue tones water colors so it is out of this world. Playa Pilar is one of the most perfect beach i have seen. It is advertised as THE prettiest beach in the world, Ok for the beach but the surroundings is very wild and dry.

For the rest of the stuff, forget about it, it will be in my R & D projects for subsidies from GVTs.

would love to see some pics... (or collaborate making drawings)

as that sounds somewhat like my fantasy roadable.

cheers,

Chris