Speed Measuring?
02-01-2011 | 05:54 AM
#4
Senior Member
RE: Speed Measuring?
Least expensive way to measure land speed for anything is with a stop watch and pencil and paper. pretty easy too. It is easiest to do with a friend but not impossible alone.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
02-01-2011 | 08:19 AM
#5
RE: Speed Measuring?
Last year I bought a Bushnell Radar gun. It was somewhere around $70 and I think it's the one in the link below. Not mentioned was it's ability to display either kph or mph, but it does do both. One word of caution, it's best to let someone use it who is NOT holding the transmitter.
http://www.amazon.com/Bushnell-CBV00...6576995&sr=8-1
There's another one on Amazon for only $70 as well. Not sure what the difference is.
http://www.amazon.com/Bushnell-CBV00...6576995&sr=8-1
There's another one on Amazon for only $70 as well. Not sure what the difference is.
02-01-2011 | 08:24 AM
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From: milbrae,
SK, BANGLADESH
RE: Speed Measuring?
ORIGINAL: DaveG55
Least expensive way to measure land speed for anything is with a stop watch and pencil and paper. pretty easy too. It is easiest to do with a friend but not impossible alone.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
Least expensive way to measure land speed for anything is with a stop watch and pencil and paper. pretty easy too. It is easiest to do with a friend but not impossible alone.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
02-01-2011 | 08:50 AM
#8
Senior Member
RE: Speed Measuring?
ORIGINAL: sloppyG
this is the best economical way, unfortunately I get the feeling most people would rather spend $100 than do 3 minutes worth of math
ORIGINAL: DaveG55
Least expensive way to measure land speed for anything is with a stop watch and pencil and paper. pretty easy too. It is easiest to do with a friend but not impossible alone.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
Least expensive way to measure land speed for anything is with a stop watch and pencil and paper. pretty easy too. It is easiest to do with a friend but not impossible alone.
For ground vehicles:
Put two lines on the ground 132' (44 yds) apart. Do this in an area large enough that you can be running at speed when you cross the first line.
Activate the stop watch when the vehicle crosses the first line and stop it when it crosses the second line.
Take the time on the watch (I'll use 2.5 seconds as an example) and multiply it by 40 - 2.5 x 40 = 100 (this number is how many seconds it would take to go 1 mile at that speed)
Now divide 3600 (seconds in an hour) by the number above (ex = 100) -3600 / 100 = 36 MPH
For land speed (not air speed) of a plane just use longer distances and change the multiplier. 176 yds (528') multiply by 10 or 88 yds (264') multiply by 20. The rest is the same.
Of course the accuracy you get will depend on the reaction time of the person using the stop watch but you will get a decent estimate of the speed w/o having to strap anything to the vehicle or buying any equipment.
I agree that the electronic devices are cool and all but I don't want to risk strapping $50-$100 worth of electronics to an rc going 30+MPH and there are a lot of things I want that I could spend $100 on.
02-01-2011 | 10:06 AM
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From: Aurora, CO
RE: Speed Measuring?
ORIGINAL: Argess
Last year I bought a Bushnell Radar gun. It was somewhere around $70 and I think it's the one in the link below. Not mentioned was it's ability to display either kph or mph, but it does do both. One word of caution, it's best to let someone use it who is NOT holding the transmitter.
http://www.amazon.com/Bushnell-CBV00...995&sr=8-1
There's another one on Amazon for only $70 as well. Not sure what the difference is.
Last year I bought a Bushnell Radar gun. It was somewhere around $70 and I think it's the one in the link below. Not mentioned was it's ability to display either kph or mph, but it does do both. One word of caution, it's best to let someone use it who is NOT holding the transmitter.
http://www.amazon.com/Bushnell-CBV00...995&sr=8-1
There's another one on Amazon for only $70 as well. Not sure what the difference is.
02-01-2011 | 10:53 AM
#12
RE: Speed Measuring?
i just count how many times it flips and cartwheels, lost wheels are atleast 70mph
i used to care about top speed, now im just happy with something i can barly controll
i usually use a therohetical speed formula and used distance/time before.
i used to care about top speed, now im just happy with something i can barly controll
i usually use a therohetical speed formula and used distance/time before.
02-01-2011 | 11:22 AM
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From: milbrae,
SK, BANGLADESH
RE: Speed Measuring?
also, consider what you're going to do with the info
are you going to be dissapointed if you find out your RC is only going 22 mph?
sometimes not knowing the answer is more fun
are you going to be dissapointed if you find out your RC is only going 22 mph?
sometimes not knowing the answer is more fun
02-01-2011 | 01:24 PM
#15
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RE: Speed Measuring?
ORIGINAL: Moontan13
I'd be doing this alone, and I'm not sure I could manage the stopwatch and transmitter at the same time.
I'd be doing this alone, and I'm not sure I could manage the stopwatch and transmitter at the same time.
02-01-2011 | 01:29 PM
#16
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RE: Speed Measuring?
ORIGINAL: moe7404
do you have to have a license to broadcast radar?
do you have to have a license to broadcast radar?
02-01-2011 | 01:42 PM
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From: milbrae,
SK, BANGLADESH
RE: Speed Measuring?
if you want a rough estimate, there are calculators online that will roughly gauge your speed based on gearing/battery/motor
http://www.scriptasylum.com/rc_speed/top_speed.html
http://www.scriptasylum.com/rc_speed/top_speed.html
02-01-2011 | 01:51 PM
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From: Los Angles, CA
RE: Speed Measuring?
ORIGINAL: 378
I'm kinda iffy on radar guns though. Police quality guns have been known to clock trees going 90MPH before, and they're way higher quality than the ones we have available.
I'm kinda iffy on radar guns though. Police quality guns have been known to clock trees going 90MPH before, and they're way higher quality than the ones we have available.
02-01-2011 | 01:59 PM
#20
RE: Speed Measuring?
ORIGINAL: sloppyG
if you want a rough estimate, there are calculators online that will roughly gauge your speed based on gearing/battery/motor
http://www.scriptasylum.com/rc_speed/top_speed.html
if you want a rough estimate, there are calculators online that will roughly gauge your speed based on gearing/battery/motor
http://www.scriptasylum.com/rc_speed/top_speed.html
The stopwatch is actually quite accurate as the delay in reflex in starting the watch is close to the same as the delay in stopping the watch. It's just that you need a very long straight stretch where you are doing WOT the whole time.
With a RADAR gun or Speed meter, you will record the peak speed which is probably what you want for bragging.....LOL.
Super-Cheap method (and you're wacky if you really try it): You could put sand in a funnel and attach the funnel to the back of the RC vehicle. The faster it goes, the thinner the trail of sand....less grains per inch. So count the number of grains over a 1" space. Compare the grains to those dropped from a full size car at known speed. Maybe the wife and kids can help? Would make quite the Youtube video......LOL.
02-01-2011 | 02:00 PM
#21
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RE: Speed Measuring?
ORIGINAL: Chuck Finley
Nothing wrong with that from the police's point of view [:@]
ORIGINAL: 378
I'm kinda iffy on radar guns though. Police quality guns have been known to clock trees going 90MPH before, and they're way higher quality than the ones we have available.
I'm kinda iffy on radar guns though. Police quality guns have been known to clock trees going 90MPH before, and they're way higher quality than the ones we have available.
02-01-2011 | 03:26 PM
#22
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From: poinciana, FL
RE: Speed Measuring?
try this http://www.eagletreesystems.com/Stan...standalone.htm
seen these and they seem to work well
seen these and they seem to work well
02-01-2011 | 04:07 PM
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From: Aurora, CO
RE: Speed Measuring?
ORIGINAL: cremation101
try this http://www.eagletreesystems.com/Stan...standalone.htm
seen these and they seem to work well
try this http://www.eagletreesystems.com/Stan...standalone.htm
seen these and they seem to work well
02-01-2011 | 05:27 PM
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From: milbrae,
SK, BANGLADESH
RE: Speed Measuring?
ORIGINAL: Moontan13
Interesting device! Works with telemetry and data logging too. Verrry nice!
ORIGINAL: cremation101
try this http://www.eagletreesystems.com/Stan...standalone.htm
seen these and they seem to work well
try this http://www.eagletreesystems.com/Stan...standalone.htm
seen these and they seem to work well
it's a pitot tube speed sensor, it's for planes
02-01-2011 | 06:05 PM
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From: Buffalo, OK
RE: Speed Measuring?
I have a Garmin Forerunner 201 wristwatch-like device that will record your track, set waypoints, record top speed, and distance traveled.
I converted a Goldberg Eagle II to electric. I put the Garmin inside the hatch. Flew the plane. 117 MPH!!! I wonder if Ishould have put the Garmin somewhere not next to my ESC.
I haven't had a chance to re-run the test, every time Iget to the flying field, I've forgotten to bring foam or something to secure it so it doesn't flop around inside the plane.
I converted a Goldberg Eagle II to electric. I put the Garmin inside the hatch. Flew the plane. 117 MPH!!! I wonder if Ishould have put the Garmin somewhere not next to my ESC.
I haven't had a chance to re-run the test, every time Iget to the flying field, I've forgotten to bring foam or something to secure it so it doesn't flop around inside the plane.
