Solar Car

[Archangel4life]

ok, here's the bit, Im a high school student working on a solar car project. ive made a frame out of 1 1/4 inch pvc, and i have a fiberglass seat and a solar panel from bp rated at 75 wats EDIT ( 12 Volts)

im having the darndest time trying to find a motor and a possible way to gear this crazy thing to get it to move.

i have a reedy modified rc car motor, its got the right wattage i think, but heh its 6 volts i believe and i dunno if thats wise to try and hook that up to the solar panel

anyway, this project is real rough and well im really having trouble trying to find a solution to that power problem all solar cars have.

my budjet is probably 500 bucks right now (i think thats what the school will pay ) anyway, if you guys can help me at all that'd be great.

 

[Nigel Goodwin]

Well you haven't filled your location in, so we don't have any idea where you might be!. As you mention 'bucks', presumably you are in the USA?, but that covers a huge amount of ground.

So, really you need to mention where you are, and how sunny it is, a solar panel rated at 75W requires incredibly bright sunshine to produce it's rated output (think Death Valley in the summer at noon!). Assuming you are not in Death Valley?, I would advise measuring the output of the panel under the conditions you are trying to use it.

 

[Johnson777717]

If I may add some suggestions?

Some other factors to selecting the proper motor would be:
1. How much weight are you planning to drive, using this motor. Basically, how heavy of any object? This will lead you to finding what kind of torque you need from the motor.

2. How fast, or at what speed are you looking to drive this car? This will clue you into how many RPM's you will need going to the drive shaft of the car. This will be based upon the torque as well.

3. Finally, given the torque and RPM's, this should give you a pretty good value as to what voltage and amperage motor you will need. But, this will be based upon any gearing that you intend to install between the motor and the drive shaft.

I wouldn't suggest pushing more volts than a motor can handle. While the motor may work for a short while, you may end up overheating the motor, or causing arcs between the armature(s), which will destroy the motor itself. It'll smell pretty bad too. Most motors, or motor manufacturers will tell you the max voltage and current the motor can handle, and usually, they will tell you what kind of RPM's and torque you can expect at a given voltage and amperage.

it may be easier to find a motor that will work with the voltage and amperage that your solar panel will deliver (given direct sunlight). Then see what kind of torque and RPM's the motor will provide. Then you can either adjust the pinion and spur gears to suit the needs of the vehicle, or go with a different motor. Either way, I suggest developing a gear system which will allow you to place different spur and pinion gears into the system, so that you can adjust the RPM's and torque. Take a look at an RC car system, which uses an electric motor. These systems are as basic as they get, and provide measures for adjustment. I used to race RC cars when I was 14, and racing involves adjustment of these factors to improve performance. Thus, this is why I suggest this in this type of system, which will allow you to cover some of the unknown factors.

if you have no clue what I'm talking about (With all due respect) I suggest looking at a mechanics book to find out how motors (RPM's and torque and gearing ratios) work. By mechanics I mean a book which discusses the physics behind mechanical items, as opposed to a vehicle mechanics guide.

I wish you good luck. It may be a little vague right now. A littl trial and error will help you figure the system out.

 

[Archangel4life]

alright well im not so incompetent in this subject as i may seem, i wrote that thing at like 12:30 at night so yeah sorry about that.

im in the chicagoland area,or midwest of the united states. and well now ive got a few more questions..

ive found a motor that MAY work alright, here's a link

https://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611762115&ccitem=

1/35 of a horse is a little bit small for how much power i will have out of this solar cell, but im assuming i wont have 75 watts to power this thing due to the angle of the earth relative to the sun. that and smog, and clouds.

Im looking to get this car moving with one person on it. im hoping for it to weigh no more than 200 pounds with the person on it.

right now i have casters with rollerblade wheels and abec 5 bearings, as i know inertia will be the biggest part of getting this thing moving.

as for gearing, i think it will be incredibly difficult for me to build a gearbox with the ratio i think i may require. from what ive been told ( and somewhat calculated) i need somwhere between a 600-700:1 ratio for the drivetrain.

thanks alot guys ill try not to respond when im tired i tend to type stupid and sluggish.

i hope this is a bit better than the first post

 

[Nigel Goodwin]

im in the chicagoland area,or midwest of the united states. and well now ive got a few more questions..

1/35 of a horse is a little bit small for how much power i will have out of this solar cell, but im assuming i wont have 75 watts to power this thing due to the angle of the earth relative to the sun. that and smog, and clouds.

My geography isn't very great, but I seem to recall that Chicago is well north in the USA?. Presumably the climate isn't tropical?, and probably more like that in the UK?.

I would suggest you really need to find out what the panel will deliver under the conditions you plan to use it - you could use a 12V headlamp bulb, an ammeter and a voltmeter to measure the output of the panel. Be prepared to be really disappointed!!!.