After seeing the hovercraft in the auto section I had a great idea for my Sr. design project, make a paddle boat! But no one in my group wanted to… So one of the choices that were on the board were a hovercraft.
My design would like to accomplish the following:
Hold one person
Be able to steer
Divert air to both the skirt & for propulsion, not one of those faggy HC’s that just float and someone pushes you
Float at least 6"
I’d like it to go at least 10mph
Use about a 8-10hp gas engine
I never took propulsion because it wasn’t part of the mechanical course schedule. I have been studying my dick off on designing this thing but my mind is boggled trying to design a skirt! Diverting the air to both propulsion and lift doesnt seem too bad.
If anyone knows anyone that sells or builds these and are willing to give me some advice, that would be great. Thanks!
What exactly are you looking to buy? We are just about finished rebuilding / upgrading ours. We researched and purchased more efficient skirts and fan also.
We’ll be out testing it probably this Saturday. And then it will be out a lot after that if you want to check it out and learn more about how it works.
there was once an episode of Junkyard Wars on hovercrafts, I suggest looking it up because everything right down to the skirts was DIY from junkyard materials.
I’ve built a few leaf blower hovercrafts with students before, The trick is to get the air flow directed out evenly on all sides, we used CAD to draw up the design, then a CNC router and vinyl cutter to get it all within spec. The skirt needs to be overlapped in such a way that it allows it to balloon out, but not bulge at the bottom, using a system of slits and circle cut outs, we got the right amount of air released/air inflated by using washers to hold down a symmetrical pattern of washers to the bottom platform.
Lemme go through some of my stuff and see if I can find the CAD drawings we made for the skirt.
Hopefully Dr. Soom likes you, because if not he can be a tough grader on senior design projects. Luckly I was on his good side, so it made my project pretty easy.
A whole vehicle is pretty ambitious but just show that you put thought into things, follow the design process, do some calcs and you’ll be fine. You really shouldn’t have to buy anything. I think the first step would be to take a look at camarojoe’s craft and any parts he has. Pick some things that you’d like to improve upon or change from that design.
Well our craft is just for one person but im sure I can scale something down, the biggest thing im thinking of right now is how to divert air for propulsion and lift, some crafts use two motors some one
if anyone has a 7-10hp motor for sale let me know!
OT. I had Soom for my senior design project. I was doing Battlebots anyway at the time, so i just wrote a report on it as if my sole purpose of competing was for the senior design project. win/win.
why not use one motor for 2 blowers…own that down feeds into the skirt the the other that swivels allowing you to steer?
Awh you have four guys, which is a huge help. For my project it was just two guys. We did a self dispensing flow rate monitored filtered water dispenser for people who where bed ridden.
Aka a Britta water filter, with a Jeep windshield washer pump, and an integrated plc to monitor rates with a camel pack style feed tube and a vacuum sensor.
Plus with a motor capable of powering two blowers, you add weight, which can exponentially cause effects in other areas of design.
For the one hovercraft we designed a system in which you diverted the air between a tunnel and exit port, the tunnel filling the skirt and the exit port providing thrust. The problem we ran into was that the ratio between air diverted and air exited was either too much or too little for each direction. That is, if you divert too much into the skirt, you dont move, just float. But if you divert too much air for thrust, you don’t achieve the proper lift cushion and end up tearing your skirt. It was a lot of trial and error, and we considered using the two blower suggestion but it wasn’t practical to redesign everything at that point.
I’ll give you a hint at what we did…Gas powered thrust…electric powered lift…(think treadmill motor)
Also, when looking at fan blades (airfoils) you need to be very careful you chose the correct angle of incidence and angle of attack in relationship to the thrust you are seeking to achieve, both for the skirt inflation and for the thrust/directional force.
If you have any question, shoot away. I went through the entire trial and error process and I THINK that I have a good grasp on this topic. I’m gonna look at my files at school to see if I still have the designs, if I do find them I can email them to you.
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Also, reconsider your goal of floating 6 inches lol. That is far beyond the capability that you are going to even come close to. For this, you’re going to be lucky enough to get the thing 1/2 an inch off the ground once fully inflated let alone achieve proper even lift lol.
The design I keep picturing in my head is a basically flat deck with a skirt attached. Motor/fan shroud in the back mounted on a pod. The pod has a section cut out to direct some of the air down through a hole in the deck, filling the skirt. It took me a while, but I found a model of what I had in mind.
You’d have to do some calculations based on lift/HP/thrust to figure out how much air you would need to divert to get lift. What ever you’re left over with provides your propulsion. As a design project it’s not like it has to go very fast. Add a pair of steerable rudders behind the fan much like an airboat and you should have a functioning hovercraft.
You also have to consider the significant amount of danger involved with swinging a propeller of this size behind a gas engine. Should your design fail, like say in the motor mount area, this project could easily kill someone. I’ve been around RC planes most of my life and even a wood prop behind a .40 nitro RC plane engine will take a finger off as quick as any circular saw. Move up to full scale and you’re talking head/limb removal.
Interesting thing to think about though. If you’ve got a 200 pound dude sitting on a weightless 3’ x 3’ platform you’d have to maintain 0.154 psig with 12 feet of interface for the compressed air to leak out of. On a 2’ x 2’ platform you’d only have 8’ of interface but you’d need to maintain 0.347 psig. So it’s an optimization problem: the bigger the platform the less pressure you need, but the bigger the platform the more area you have for leakage so the more flow you need. Some curves showing the optimum point for the size of your shit oughta show up somewhere in your project.