GOAL: Design, engineer, and fabricate a battery-powered vehicle that covers an obstacle course in the shortest amount of time.
I am in TSA and I am building a hovercraft, the requirements are:
Vehicle
-does not exceed 8" wide/ 8" tall/ 12" long
-encouraged to design and fabricate the vehicle using common items such as paper, wood, plastic, metals and composites
-no commercial model kits or pre-assembled vehicles
-use of pre-assembled gear trains, drive trains, or other commercial systems is prohibited
-no wheels are used to support the hover craft. Lift is to be provided by air.
Power Train
-two AA batteries supply electrical power
-a single 1.5-3 VDC motor
-motor must not be disassembled or altered in any manner
-no additional energy sources, such as rubber bands, springs, solar cells, ect., are permitted
Obstacle Course
-27' long/ 12' wide @ start line and 3' wide @ finish
-course may be a variety of surfaces, such as carpet, concert, tile or wood.
-sidewall is 3"-6" above the surface
-fabricated to allow a straight run through the center of the course
-course is littered with 30 obstacles that do not exceed .75 inch tall by 3" by 12". Some may be stationary and others movable.
Can you use wireless remote control servos? or do you just point in the general direction and Hope for the best?
it isn't remote controlled you just turn it on and let it hover
I'll take a whack at it, (but don't blame me if you loose). For this application you don't need a bunch of engineering,, just build it, test it,, and if needed modify it.
EBay for the highest rpm 3v DC motor you can find , get one or two ~4" model airplane propeller (Carbon fiber if you can find one),, A small toggle switch, some telephone cable (wire) A 2 cell battery holder,, one 0 -1000 ohm variable resistor (pot) Mount this all on balsa wood cut to an oval shape. cut 4 struts and make small skis to put under the board. Put 1 on each side and 1 at the front and back. (don't forget to bend the skis up at their front edge) Brace the struts very well. The struts should hold the base only about one inch above the floor. Wrap a ~ 1 1/2 inch flexible black plastic (12 mills should do fine) around the outer edge (make sure to mount the front strut far enough back so that the plastic won't touch it) Now I would mount the prop to point straight out the back (like an air boat) But just in case that's not allowed mount it above a hole in the balsa board and use the placement of the battery pack to balance it just a bit nose heavy. You will of course need some duct tape. <grunt,,, grunt, grunt>. Balancing it will be the hard part. Keep everything as light weight as you can (ie: glue instead of screws) If wiring is an issue let me know and i can give you a drawing. If you mount the motor pointing down you will need to fold the plastic and put some type of weight in the bottom of it ( a small chain)
EBay for the highest rpm 3v DC motor you can find , get one or two ~4" model airplane propeller (Carbon fiber if you can find one),, A small toggle switch, some telephone cable (wire) A 2 cell battery holder,, one 0 -1000 ohm variable resistor (pot) Mount this all on balsa wood cut to an oval shape. cut 4 struts and make small skis to put under the board. Put 1 on each side and 1 at the front and back. (don't forget to bend the skis up at their front edge) Brace the struts very well. The struts should hold the base only about one inch above the floor. Wrap a ~ 1 1/2 inch flexible black plastic (12 mills should do fine) around the outer edge (make sure to mount the front strut far enough back so that the plastic won't touch it) Now I would mount the prop to point straight out the back (like an air boat) But just in case that's not allowed mount it above a hole in the balsa board and use the placement of the battery pack to balance it just a bit nose heavy. You will of course need some duct tape. <grunt,,, grunt, grunt>. Balancing it will be the hard part. Keep everything as light weight as you can (ie: glue instead of screws) If wiring is an issue let me know and i can give you a drawing. If you mount the motor pointing down you will need to fold the plastic and put some type of weight in the bottom of it ( a small chain)
Power is just 2 AA batteries?????
YIKES
BUILD IT AS SMALL and LIGHT AS FRIGGIN POSSIBLE.
You need to use some of the thrust to propel the vehicle forward and the rest to make it hover and you've got only a very small amount of power to work with.
Arthur
YIKES
BUILD IT AS SMALL and LIGHT AS FRIGGIN POSSIBLE.
You need to use some of the thrust to propel the vehicle forward and the rest to make it hover and you've got only a very small amount of power to work with.
Arthur
QUOTE (adoucette+Mar 15 2008, 03:11 PM)
Power is just 2 AA batteries?????
YIKES
BUILD IT AS SMALL and LIGHT AS FRIGGIN POSSIBLE.
You need to use some of the thrust to propel the vehicle forward and the rest to make it hover and you've got only a very small amount of power to work with.
Arthur
Thats why I said I would point the motor out the back like an air boat.
It would skid along on the skis and just look like a hovercraft.
YIKES
BUILD IT AS SMALL and LIGHT AS FRIGGIN POSSIBLE.
You need to use some of the thrust to propel the vehicle forward and the rest to make it hover and you've got only a very small amount of power to work with.
Arthur
Thats why I said I would point the motor out the back like an air boat.
It would skid along on the skis and just look like a hovercraft.
QUOTE (bigideas82654+Mar 12 2008, 09:28 PM)
-no wheels are used to support the hover craft. Lift is to be provided by air.
i think it actually has to hover
i think it actually has to hover
it's also going to be inspected by judges who probably don't know much about hovercrafts.
Tell them that the skids are there in case the motor fails,, 
thanks but i think that they will notice
Hey bigideas
Sounds like fun.. I would start with a disposable aluminum pie pan for the body.. with a skirt made of disposable plastic bag.. (the bottom perimeter must be smaller than the top) the prop would be mounted forward with the fan blade vertical and the air ducted into the body.. the forward mounting should provide forward propulsion as well as lift. A rudder can be one or two playing cards positioned where desirable.
Good Luck
Jack
that's a great idea i'll try it out. thanks Jack. 
You're welcome..
BTW... if the pie tin weighs too much... try a styrofoam plate instead.
Jack
Thanks everybody for your ideas. Any others would be wonderful.
You haven't won yet?
I'm going to compete Friday 25th. I'll let you know how it goes.
Alright,, Go get um,,
Can you post some pics of the project?
Can you post some pics of the project?
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