Automatic Spoiler - rise and unpack jsut like porche but with extras

tempgp · 07-16-2009, 11:01 PM

hey all i have another crazy idea.
I want to build automatic spoiler that sits inside flat surface of the trunk but then in needed it gets outside and unpacks itself.

Basically want to combine original idea from Porshe + aircraft wing folding technology + cool useless actions from transformers cartoons just for fun. Still want to keep car to look conservative (no sports) but if needed lets unpack.

Technically considering my aircraft engineering experience should be a peace of cake to build. Only problem i can not use gas tubes or oil based actuators as i don't drive truck. I have pneumatic compressor but its low pressure -- no good. So i have to stick with linear stroke actuators. good once are mad expansive, and cheap one too fast in motion so it will brake all mechanics ... so i probably will end up building my own version. Or maybe will use rotary actuators. if theu dont chop my fingers they can lift just about anything

So what do u think? Lets build a transformer car

trader007 · 07-19-2009, 04:49 PM

i would think a basic servo motor could work well. that would allow you to go at variable speed

Crinos · 07-19-2009, 05:03 PM

What would the pressure on the motor(s) be when the spoiler should unfold?

Since you have a spoiler, my guessings is that it will give some amount of downforce, and the downforce increase with speed.

tempgp · 07-19-2009, 06:00 PM

if we treat it as aircraft wing (tail eleron) then at speed 60mph temp 58F avarage pressure would be 14 PSI (under the wing) oh ye thats calculating at 0 agngle.
Now if u want get bette traction at the same speed we can force your rear part of the car down and get lift of -904 lbps at 8 Degrees (i used 8 from reference to speed boat standard) Of cause those 900 punds is what will be pressing on the frame... so i will need locking mechnizm. But for parts when wing is being actually released from the trunk we can keep angle at 0 % relative to the surface (we can use gyro to get surface level) in that case lift will be 0 lbs and only pressue thta applies is the wind pressure which is only 14 psi (just about any actaultor will be able to bare that)

I say interesting projject to play with... but now i need some one with carbon fiber trunk cover to put it in =)

I also builded concept actuator yesturday night. Now i need to improve it to be able to hande waights caz i builded it from icecreme sticks =)

tempgp · 07-19-2009, 06:09 PM

here are some simulations that i just run

csfile · 07-19-2009, 10:07 PM

subscribed...this looks like it can be a very interesting project.

tempgp · 07-19-2009, 10:33 PM

lol now i need some inspiration and budjet to finish it + good gas mask for all fabrcations =)

Welll will post few progress pix tommorow

DigitalVampire · 07-22-2009, 09:53 AM

Other than the SHOW-OFF factor, how much percentage of cars really needs a spoiler?

I don't understand why FWD cars ever need a rear spoiler at all.

soundman98 · 07-22-2009, 10:02 AM

Quote: Originally Posted by DigitalVampire

Other than the SHOW-OFF factor, how much percentage of cars really needs a spoiler?

I don't understand why FWD cars ever need a rear spoiler at all.

while the effect is better enhanced by having a car with awd, or rwd, the spoiler on fwd cars helps keep the rear wheels planted, to an extent(without it it sometimes feels like the back of the car is on marbles). i think that there is a argument though that a 6ft tall, 6 foot wide 'show' spoiler has no better effect than a standard 2 foot tall 4 foot wide performance spoiler has.

tempgp · 07-22-2009, 12:07 PM

to me spoiler is just a wing that perfoms regular airdynamic functions. If you have RWD then if you have - angle (negative) then there is more traction to your tires. So if you want to make quick turn you a** wont get losesn. Sure you can do norvegian turn and you wont loose control.

Alsio iffor any reason you want you rear to loose friction you can set angle to + and all liftpower will apply. Look at rendering charts on how much friction/lift can get

Get your car waight and see Lift value... Lift is how much wight wing can lift at any given spees, ange combination. POsitive value you r trying to take off the ground. Negative presses u in the graound.

Persinally I dont need spoiler, i just wanna build something cool abd cheper then self maid aircraft =)

malcom2073 · 07-22-2009, 06:14 PM

Wasn't there an article somewhere which proved negligible gains for spoilers below 100mph or something?

tempgp: I mean no offense by this, but I suggest proofreading your posts or getting a browser with a spellchecker before posting. People might take you more seriously if your posts don't look like they were written by a 12 year old.

tempgp · 07-22-2009, 08:55 PM

oh sorry im just 7 y/o so your comenta is N/A, but if you relly prefer so I can post it in Russian

As to 100mph efficiency. Thats all depands on your angle of the wing. If you dont plan to travel more then 80 you can safly put say 14-18 degrees (but if you hit 100+ speeds you will feal that back of the car is pressed down to the ground) and if you go to say 135 (or more if you dont have governor) then you may brake strings or lover the car to the level of the ground and get lots of spartks =)

In another words speed + angle = derectly propostional to efficiency. Min speed though is 60mph. You can try yourself, get 40+ mph and put your nahs outside the window, make sure your fingers are close togather then play with different angle position, then go to ~60-80 mph and see the difference. (Airctaft take off speed is 60-80mpg. 60 for small propeler one, 80 for jets... or hmm well thats in should be in km/h, russian Mig29 takes of at 80Km/h with flaps extended)

Crinos · 07-23-2009, 05:19 AM

Quote: Originally Posted by tempgp

to me spoiler is just a wing that perfoms regular airdynamic functions. If you have RWD then if you have - angle (negative) then there is more traction to your tires. So if you want to make quick turn you a** wont get losesn. Sure you can do norvegian turn and you wont loose control.

What the **** is a "Norwegian turn" ???
Just curious, since I'm a Norwegian myself....

Crinos · 07-23-2009, 05:25 AM

Quote: Originally Posted by tempgp

oh sorry im just 7 y/o so your comenta is N/A, but if you relly prefer so I can post it in Russian

As to 100mph efficiency. Thats all depands on your angle of the wing. If you dont plan to travel more then 80 you can safly put say 14-18 degrees (but if you hit 100+ speeds you will feal that back of the car is pressed down to the ground) and if you go to say 135 (or more if you dont have governor) then you may brake strings or lover the car to the level of the ground and get lots of spartks =)

In another words speed + angle = derectly propostional to efficiency. Min speed though is 60mph. You can try yourself, get 40+ mph and put your nahs outside the window, make sure your fingers are close togather then play with different angle position, then go to ~60-80 mph and see the difference. (Airctaft take off speed is 60-80mpg. 60 for small propeler one, 80 for jets... or hmm well thats in should be in km/h, russian Mig29 takes of at 80Km/h with flaps extended)

Takeoff speed for a MIG-29 is 260-280 kph (aprox 481 - 518 Km/h).

http://www.saunalahti.fi/fta/MiG-29-2.htm
http://www.zap16.com/mil%20fact/mig-29.htm
http://warfare.ru/?catid=255&linkid=1600

malcom2073 · 07-23-2009, 05:48 AM

http://www.aerospaceweb.org/question...ce/q0088.shtml

That's way faster than 80mph tempgp. You still sure they are effective at such slow speeds?

Quote:

As to 100mph efficiency. Thats all depands on your angle of the wing. If you dont plan to travel more then 80 you can safly put say 14-18 degrees (but if you hit 100+ speeds you will feal that back of the car is pressed down to the ground) and if you go to say 135 (or more if you dont have governor) then you may brake strings or lover the car to the level of the ground and get lots of spartks =)

So you're saying that yes, wings at any reasonable angle are not effective below 100 mph?

On a side note, if your springs break before bottoming out, you need to get new springs. The average passenger car probably would require 600+lbs of force to bottom out on the suspension hard stops. Are you saying a normal sized aftermarket wing (eg not something sprint-car sized) puts down that much force at 135mph? Please tell us where you found this information. Your simulator does not take into account the aerodynamics of a car, only for freestanding wing shapes which is an entirely different ballgame. You as a self proclaimed aircraft engineer should understand this.

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