SpikeX

As most of you know, I am currently working on my Savage XDragâ„¢ Project, and I would like to make a video showing the speed of the truck before being modified, then the speed after modifications.

Someone mentioned on another thread that I had to draw two lines, and film the Savage going top speed from one line to the other with a video camera. He then said that I could use the video editing software on my computer to calculate how many seconds it took the truck to go from one line to the other, and that I could measure the vehicle's speed accurately based on that.

Can anyone elaborate on this method? Do you think this method would work, and would it be accurate?

Stablock

You don't need a video camera.

Draw two lines 100 feet apart. You'll need room on either side of the lines for braking and to reach your top speed. Do it on a nice level road. Then you'll need a stop watch and someone to time you. Get your truck up to operating temperature and do a run. You want your truck to be at top speed when you hit the first line and continue until you hit the second line. Get that someone to start the timer as soon as your truck starts to cross the first line. That someone will have to stop the timer as soon as your truck starts to cross the second line. Do it a few time. This will allow the time keeper to get some practice on the timing. Then, do it several time in both direction and record each time. Now, with your calculator, take 100 divide by your average time and multiply that by .68 and it will give you your speed in mph.

for example. If your average time between lines was 1.8 seconds.

then...

100/1.8x.68=37.77 mph.

If you record several times and take the avrage and then do the math, it will give you an accurate MPH. If you use a camera for one run, you will get an accurate MPH for that run ONLY.

amwhite2005

Using a camera only complicates the thing. I did mine in a field, with screw drivers stuck in the mud so you could see the lines easier. Get 1 person at the end to time it. Just make sure you dont hit the screw driver, they will go flying - mine did at 25MPH.

SpikeX

But when you use someone with a stopwatch, doesn't that make the speed unaccurate (due to reflexes)?

Ziggmiester

That's why you do it multiple times. The hope is that the person controlling the stopwatch gets the timing of your truck down, so he/she can hit the stopwatch with anticipation rather than reacting with reflexes alone.

Vigilante212

Any method will have its flaws. Your only going to be accurate to within +/- 3 or so MPH per run do 10 runs and take the average it will give you closest approximation of speed.

dracohowe

unless your timers are reeeeaaaaaaallllly slow lol

amwhite2005

Yes, but unless you want to go out and buy a top-of-the-range radar gun (£100s), then this is your best method.

itsnotskidding

i wonder if you sat on your savage and went past a camera over the limit.. say 30mph zone and you do 35mph.. would you get flashed or fined..ha ha...

SpikeX

Good idea; I should try that.

There was someone on the HPI Racing Forums who's Savage got caught by a speed camera in the UK. He posted the picture on the internet.

I have to admit, I've broken the speed limit many times with my Savage. I once went WOT (about 65km/h) with my Savage X in a 30km/h zone.

SAVAGEJIM

Try to get a set-up that nitro drag racers use at the track: laser speed traps! Lasers are accurate to the billionth of a second. Also, I would suggest what on-road racers use: transponders and sensors. This might be less accurate than the laser speed trap, but it is still way better than a camera, chalk lines, and stopwatches. Even on video, it will be a pain to go frame by frame on computer to determine just when the very tip of the front bumper crosses the first line and when it crosses the second line; especially if you are videoing from an angle!

Crzybri82

just go out and buy one of these

http://www.hotwheels.com/showcase/pr...&category_id=6

HAHAHA.......wonder if it would really work??[sm=50_50.gif]

rcnitrohead

Lol its worth a shot..[:-]

ned289

That's what I was going to say.... get a radar gun. LOL

Crzybri82

or just make friends with someone on the local police department and see if they will help ya out.

SAVAGEJIM

That is just a toy. I have a Bushnell and it is way better.

Check out the thrashing that Hotwheels folly takes in this thread:
http://www.rcuniverse.com/forum/m_53...tm.htm#5362981

Crzybri82

hahahaha yeah i know, my nephew has one and it clocked a regular car doing 25mph at 102mph in "regular mode", its a joke.