| Author | Message | ||
     Anonymous |
why not make a homercraft. take apart a small hair-dryer and get the fan out of it. if the fan has a shroud(plastic ring around propeller) stick it into some foam and use a plastic bag to make a bag type skirt(glue bag onto foam to seal). to power it use 2 or 3 9 volt batterys. i made this and it works great but i never really centered the weight and it went out of control. | ||
| Simon Quellen Field (Sfield) |
A hovercraft is a fun project. To power it with batteries, you would want to use a DC motor, not the AC motors used in hair dryers. One trick to remember about hovercraft is that they work best when they move large amounts of air at low pressures, rather than smaller amounts of air at high pressure. This means that you would want to use a fan with a large diameter. A motor running a 2 foot fan will work better than the leaf blowers that most beginners start out using. A leaf blower usually can't lift an adult, but the same motor running a large fan can do it easily. | ||
| Matthew |
If you want to use a AC motor with DC power you could just put a ceramic capacitor in series with it. You may have to fiddle with diffrent ones to get the uf right. Or you could get a variable capacitor, you can find these in any almost any kind of radio, it is the part attached to the tuning knob. | ||
| Simon Quellen Field (Sfield) |
A capacitor looks like an open circuit to DC power. No power would get to the AC motor. To power an AC motor from DC, you need an inverter. An inverter is an oscillator, usually designed to oscillate at 60 hertz in the U.S., and sometimes extra care is taken to make it output a sine wave or near sine wave, instead of a square wave. Be very careful to make certain you know your subject well before making statements here. Your words may be here for quite some time. | ||
| Matthew |
hmmm, seemed to work for me once.... oh I said in series didnt I, I mean parrallel. | ||
| Simon Quellen Field (Sfield) |
It still won't work. Get a good book on basic electronics. An AC motor generally requires the current to vary with time. A capacitor, in series or parallel, will not cause DC to become AC. Perhaps you actually had a DC motor. Connecting a capacitor in parallel with it would not prevent it from working with a DC source. | ||
| Matthew |
I thought the capacitor was suppost to form an occilator with the motors coils. | ||
| Simon Quellen Field (Sfield) |
Passive components have losses. You need active elements to make an oscillator. Something like transistors, tubes, or negative resistance diodes. | ||
| Dan C. |
I once built a hovercraft out of plywood(4 foot in diameter circle), powered by a leafblower. It used a tablecloth as a skirt. Do a google search for X Inventions and you can find plans for it. Its safe, easy, cheap, and fun. It can also lift 100's of lbs. | ||
| David S |
http://www.xinventions.com/main/hovercrafts/second.htm here this site has a great, cheap, easy to build hovercraft i built it and it works great (if you know what your doing) | ||
| David S |
Dan C. that will lift 100lbs. depending on the power of the leaf blower you put on it, weight, how good you seal everything, and how much you know what your doing in the "area of hovercrafts" | ||
| David S |
great news im in a class where we are learning how to wire houses and my teacher and the 30 students in the class are all going to help me build the hovercraft in the link below. http://www.xinventions.com/main/hovercrafts/second.htm man i cant waight till tuesday oh and for warmer temps. (here in NJ its 10F now) | ||
| David S |
the hovercraft is in testing stages now it can lift up to 250pounds and the back propeller is driven by a goped engine(direct drive)which makes the craft go up to 30 MPH. ill keep everyone here updated on the work in progress. here are some photos of what the craft will liik like http://www.xinventions.com/main/hovercrafts/second.htm | ||
| Tony |
If I were to make an oval shaped hovercraft, similar design to the one on www.Xinventions.com , powered by one leafblower at either end, would it work or would it put to muich strain on the skirt? Also, how does the skirt work? Should it be just a rim around the edge with a large space inbetween or does it have to go back on itself so that it comes between the hovercraft chassis and the ground? | ||
| Tony |
In response to Simon Quellen Field's comments on DC to AC power, Matthew's idea does actually work, i'm not 100 percent sure why but it seems to be able to act as an alternating clock pulse. The only draw. back is that at higher currents, most ceramic capacitors cant take it | ||
| Simon Quellen Field (Sfield) |
It's easy to do the experiment to convince yourself that the physics and electronics books are right. Take a battery, and place a capacitor either in series with it or in parallel, and try to detect an AC current. In parallel, you will see the same DC as without the capacitor. In series you will see no current. | ||
| William Beaty |
I think Matthew is remembering that we can change an AC motor into an AC generator by connecting a capacitor in parallel, tuning for 60Hz or whatever, then cranking the shaft at 3600RPM (or 1800, depending on rotor poles.) It will generate around 120V, and can power small appliances. AC induction motors behave as generators only when connected to an AC power supply. The coil and capacitor combine to become an AC power supply that triggers the generator effect, and the generator effect keeps the oscillator going. But only as long as someone is doing work in cranking the generator shaft. Nikola Tesla and his magnetic vortex technology with energy coupling by phase-lag trickery. But this has nothing to do with batteries. See: http://www.qsl.net/ns8o/Induction_Generator.html | ||
| Anonymous |
I have an AC motor. It has a total of 10 wires coming out of it. 2 pairs of wires are connected, and I have figured out that you can switch the connections to create a different motor, or something like that. And I know which one of them is ground. That leaves 5 wires, and I have no idea what they are for. Does anyone know anything about this? | ||
| William Beaty Unregistered guest |
> I have an AC motor. It has a total of 10 wires coming out of it. Is it a stepper motor? Turn the shaft slowly. If it goes "thump thump thump" as it turns, then it's not a normal AC motor. Some steppers can run on 120V AC though, but they need a capacitor. I don't know how you'd hook such a thing up. | ||
| Anonymous |
Im thinking of building a hovor craft but dont have much funding. I think that a gas string trimmer motor would be about right, one to power a large fan (Like Simon suggests) and one to power the fan that pushes the hovorcraft forward. Is there a place I could get this size of motor cheaper than a string trimmer? I was also thinking of having a kind of small helium filled inner tube around it to make it weigh less and keep it from sinking when you turn the engine off over water, it would also act like a bumper to keep it from being damaged. The steering would be 3 fins infront of the thrusting fan controlled by a steering wheel. Do you think it would be safe to connect the gas lines to a main tank and gas pedal? I could also connect the exaust to a pipe that leads to the back of the craft so it doesnt hit the drivers face. Also Tony had a good question about the skirt "Should it be just a rim around the edge with a large space inbetween or does it have to go back on itself so that it comes between the hovercraft chassis and the ground?". I think a hovorcraft would be a really neat project because it can go a fair speed over both land and water. | ||
| Anonymous |
hello everybody i built a hovercraft and it went around 20mph it was crazy and then i fell off and it crashed lol! | ||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 196 Registered: 12-2004 |
Neat! Post the construction details, and some photos! | ||
| lysdexia Unregistered guest |
They should really use clear skirts. I never see the hovering. | ||
| Anonymous |
Just wanted to correct you on one thing, Simon. The motor in a hair dryer is DC, connected using the heating coils as ballast and then going through a bridge rectifier before powering the motor. Just thought you'd like to know. Its easy to see where the confusion is. As far as the stepper motor goes Bill, the average stepper can even run without any cap on AC as long as the motor is syncronized first. They wont, however, have very much torque, and behave very irratically (reversing direction) when even a moderately light load is placed on them, and they generally dont run at very high speeds at 60Hz, so, they would make very poor hovercraft motors. They make good mechanical clock motors, provided you limit the current so that they run cool. | ||
| Anonymous |
Hey, just starting and dont get one thing... if you just propell air into the skirt/cushion, where does it go? I mean if you just keep proppelling air into it it will blow up! So for example if Im using a simple bag as the cushion do I have to make holes in the bag to let the air out? Please clarify it abit for me  | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 559 Registered: 12-2004 |
The bottom of the skirt is open. The air forms a cushion under the vehicle, and exits out all sides. | ||
| Anonymous |
ah.. sorry for my unintelligence (only starting), but Im not really understanding it correctly still  So the skirt thing has to only goa round the perimeter? So there is a gigantic hole at the bottom of the whole hovercraft? Also, was just wondering if computer fans are powerful enough (i doubt it really) to life its own weight uplet alone the whole hovercraft? I want my hovercraft to be very very small though :p (about 1/2 meter in length, a bit smaller in widthand not sure about height..) Thanks for any information in advance | ||
| travyp Unregistered guest |
im just starting and i was wondering what kind of battery to use for the fan. it's going to be a small single seater so it won't need to be much. thanks | ||
| Smartkid (Smartkid) Junior Member Username: Smartkid Post Number: 6 Registered: 6-2005 |
http://www.amasci.com/amateur/hovercft.html | ||
| jayson (Unregistered Guest) Unregistered guest Posted From: 71.112.90.195 |
You don't put an entire hole in the bottom. Just about 6 ,1 inch diameter holes around the center | ||
| justine aquino (Mnado) Member Username: Mnado Post Number: 20 Registered: 12-2005 |
you can also use cooling fans from computers.but it think its acputting an oscillator with a series of battery might weigh much for the fan to carry,my solution dont put a bag with holes put a styrofoam plate this will spread air more equal because when you use a bag it needs much more powerand one thing to the craft maybe adding a heating coil from the blow dryer might do some help,heat rises up right?maybe if you use that with a fan i might do some help this will onlt work good on a nice,smooth,large,glass table top my calculation for th height is maybe no more than 2 mm(when you use a plastic skirt it doesn't hover it just rises its like the plastic is blown then whenthe plastic grows it pushes the body up but not causing it to hover(the plastic skirt is like an inflatable stand for short) | ||
| Velociraptor invictus (Unregistered Guest) Unregistered guest Posted From: 139.184.30.17 |
Hi all.... i am actualy trying to see if a it is posible to make a combo between a hovercraft and a heleum blimp.....think of a small craft having its weight reduced by heleum..(but not completely)...just enough to have a small engine lift it off the ground.....any one have any info or ideas??...thanx Raptor | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 921 Registered: 12-2004 |
That should work. It will have a pretty high cross-sectional area for the wind, so it might work best indoors, and will not go as fast as one that did not have as much volume, but aside from that I see no problems. The calculations for lift are mentioned in another message for helium and hydrogen and for hot air. | ||
| Sandro Duarte (Sd10) New member Username: Sd10 Post Number: 1 Registered: 4-2006 |
It seems I'm a little bit late here but: About the hairdryer, Hummm:the motor is ac current(self exprience,i burn one once when i connect it to a 220v without the the resistent(wire that is supouse to creat the heat as the current pass by:it start moving for some seg. but them it was too much Volt to it,in my country the standart voltage is 220, i know that america is 110v)so forget about it... And about the DC to AC:you definely need an inversor none of those exprience you say seems to work properly... The INVERSOR:I create one based on a "Relé"(it's portuguese,i don't know how to say it in english);with a electroiman and a contact: the electroiman start pushing the contact to it and when it does it the switch opens and the electroiman can no longer push it so the contact goes back to the 1ºposition and close the switch again:it repeats again and again...Theres when the inversor starts: on the 1º position, the negative pole of a dc battery its connected to (let's call it)pole "x" and the positive pole its connected to pole "y" And on the 2º position(when the contact comes down)the negative pole its connected to "y",and the positive pole its connected to "x" So here you have:you'll get a square AC wave...with the same volt as you input it... TIP:After invert the current use a adapter to make it higher(How?) 1º-An adapter only works with ac 2º-when the power is inputed it goes to the 1º bobine and create a current on the 2ºbobine(smaller Volt because it have more wires then the 1º)but it stills ac 3º-it have a circuit made of 4 diods to convert th ac to dc. OK now let's do it: 4º-take the circuit of(you'll not need it) 5º-connect the ac current you got from the inversor to the 2ºbobine(the one with more wires) 6º-you'll get a very higher voltage in the end of the 1ºbobine(be carefull, i already took a shock from it..) -=And it's done=- Now all you have to do is see how much volt you want and how much wire it needs  | ||
| Justin (Commander_bob) Intermediate Member Username: Commander_bob Post Number: 42 Registered: 10-2006 |
I have made two hover crafts with hair drier motors, one with 2 9Vs and one with a li-po form my helicoptor. The motor is a DC motor but has a diod bridge on it to convert the AC to DC. Here is a video of my most recent one. It is RC and uses a PIC16F767. http://www.youtube.com/watch?v=UydSmqp9JOY | ||
| Justin (Commander_bob) Intermediate Member Username: Commander_bob Post Number: 43 Registered: 10-2006 |
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