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Hovercraft blues

NaTaN

New Member
Hi there. I am building (have built) a hovercaftf from old vacuum motors on a wood frame (I know, it's heavy). The motors are wired in series (have bypassed their original switch and go to a common switch and power source), keeping their original resistors in the circuit. My problem is this, with these (10) motors wired to one plug, the hovercraft is drawing to much power from the wall outlet and quickly trips the breaker. The engineering student next door recommends a resistor to each motor (which there already is). I'm wondering if a capacitor (either one for the whole thing or one per motor) is the way to go? I have about 8 capacitors from microwaves I could use. Or, is changing the power source from a wall outlet to a series of on board car batteries (weight) the way to go? Or should I switch from a standard outlet to one of those dryer outlets? I'm almost sure this many motors should provide enough lift (I've collected 3 more if need be), but, so far, I can't power them. I would love to see this thing work, and welcome any insight.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
First off they are in parallel, NOT in series - if they were in series they would take LESS power, so not blow the trip (but wouldn't work well enough).

If you did drop the power to them, performance drops as well, so you wouldn't be helping.

You've only got a certain amount of available energy from a mains socket - in the UK that's about 3000W - so for maximum 'blow' you only want 3000W of vacuum cleaners (less in the US where you can't get 3000W from a single socket).

How is your hovercraft designed?, and do you have a skirt?.
 

NaTaN

New Member
Yes, there is a skirt. My hovercraft is essentially a chair, with a flat round base (3ft wide, 4 ft long). The motors are placed around the chair (on the base) and wired to a switch. Behind the chair lies a fan with two ropes tied to it for steering (a left and a right). The fan swivels freely.

I'm not positive how it's been wired (I am disabled from a brain injury). I can include pics after I dig it out of the basement.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
You may be able to run more motors without tripping overloads, if you start them one at a time and allow each to get up to full speed before starting the next one.

[Motors can take several times more power when first turned on and starting from zero speed, compared to when they are running at full speed.]
 

gophert

Well-Known Member
Most Helpful Member
And all of it to the wall outlet as a power source.
How long is your extension cord?

also, an inflated inner tube from a tractor tire makes a great skirt for a demo hovercraft.
 

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