Hello everyone,
It looks like that an altimeter is 'mandatory' around here .
I searched many stores here in my country but they don't sell altimeters. Then I found a website that sells the most popular rocket altimeter: the AltimeterOne. http://www.apogeerockets.com/Electronic ... 12f4oktnm2
Is this site trusted to buy online?
I found some water rockt videos on youtube about altimeters that 'whistled' or blinking an LED. Can you give me some links about these altimeters?
I have another question: can I find one of these altimeters in aeromodelling store?
PTrockets wrote:Hello everyone,
It looks like that an altimeter is 'mandatory' around here .
I searched many stores here in my country but they don't sell altimeters. Then I found a website that sells the most popular rocket altimeter: the AltimeterOne. http://www.apogeerockets.com/Electronic ... 12f4oktnm2
Is this site trusted to buy online?
I found some water rockt videos on youtube about altimeters that 'whistled' or blinking an LED. Can you give me some links about these altimeters?
I have another question: can I find one of these altimeters in aeromodelling store?
Ptrockets
That is a reputable store. I believe a few of our members have the model you mentioned. That altimeter is what is known as a "peak altitude" altimeter. It will only store and display the highest altitude the rocket went. These altimeters are not eligible for our class A and B competitions (you would need what is called a "logging" (stores data for the entire flight which can be downloaded and graphed) altimeter to enter those classes.
I started with a peak recording altimeter. I don't really regret it, because I didn't really have a robust parachute system at the time, and almost destroyed it in a crash. However, I've since moved on to logging altimeters, and I'd highly recommend one, if you already have a robust recovery system. Even if you don't compete, the altitude vs. time plot is pretty cool and can have useful information. I have two perfectflite altimeters and I'm really pleased with them. As far as I can see, they are cheaper than anything else with similar features. It's cheapest to buy from them directly. Their Pnut altimiter looks like a great basic logging altimeter (I don't have that one. I have it's predecessor the Alt15k), and it's not much more than a basic peak altimeter. To see anything more than just the peak height, though, you also need to buy their data transfer kit for another $30.
I recently bought a logging altimeter from hobbyking, don't have the link right now but I think it cost me only $ 25,-
Haven't tried it in a rocket yet but did some testing with a rc glider and seems to work perfect. I think this is the cheapest logging altimeter you can get. Just go to the hobbyking website and search for altimeter.
PTrockets wrote:Hello everyone,
It looks like that an altimeter is 'mandatory' around here .
I searched many stores here in my country but they don't sell altimeters. Then I found a website that sells the most popular rocket altimeter: the AltimeterOne. http://www.apogeerockets.com/Electronic ... 12f4oktnm2
Is this site trusted to buy online?
I found some water rockt videos on youtube about altimeters that 'whistled' or blinking an LED. Can you give me some links about these altimeters?
I have another question: can I find one of these altimeters in aeromodelling store?
Ptrockets
That is a reputable store. I believe a few of our members have the model you mentioned. That altimeter is what is known as a "peak altitude" altimeter. It will only store and display the highest altitude the rocket went. These altimeters are not eligible for our class A and B competitions (you would need what is called a "logging" (stores data for the entire flight which can be downloaded and graphed) altimeter to enter those classes.
First of all, thanks for your help.
I want a simple altimeter (the simplest possible), cheap (the cheapest possible), reliable (as reliable as possible) and sold by a trusted store. I saw your links and which one you think is best? The altimeter APRA is the cheapest, is an altimeter that indicates the apogee by sound signals, but is it the best? All the others are a bit more expensive ...and it's a pity that the AltimeterOne isn't allowed: it is so simple and good.
I'm waiting the answer. And once again, thank you.
arjan wrote:I recently bought a logging altimeter from hobbyking, don't have the link right now but I think it cost me only $ 25,-
Haven't tried it in a rocket yet but did some testing with a rc glider and seems to work perfect. I think this is the cheapest logging altimeter you can get. Just go to the hobbyking website and search for altimeter.
Thank you for your help.
Well, it seems to be a good altimeter and it's similar to AltimeterOne. It is very cheap!!! And is it allowed in the compititions of this site? Is it equal to your?
I'm waiting for your answer.
The rules say "Rocket must carry onboard a commercially produced recording ("Logging") altimeter to document the entire flight on a Time vs. Altitude Graph to nonvolatile logging memory or telemetry to relay the altitude information to a remote logging receiver"
It sure is a commercially produced altimeter, it records the flight data and you can view the data on a time vs. altitude graph.
graph from hobbyking altimeter
140feet.jpg (211.42 KiB) Viewed 116 times
So I think this altimeter would be allowed in the WRA2 competitions (I hope it will be allowed because that's why I bought it.)
I'm going to try it in my new rocket within a week.
DogLover wrote:So altimeters that only record peak altitude are not allowed according to the official rules? That is kind of odd.
They are allowed in the altitude challenge, but that class is probably going to be replaced by the "Pop Bottle Altitude" class.
The reason why they aren't allowed in class A and B:
(coppied from the WRA2 competition rules)
"So-called "Peak Altitude" altimeters are also unacceptable because they are subject to false peak readings caused by external factors such as:
· Recovery system deployment.
· Landing impact.
· Improper installation.
· Unstable flight characteristics."
arjan wrote:The rules say "Rocket must carry onboard a commercially produced recording ("Logging") altimeter to document the entire flight on a Time vs. Altitude Graph to nonvolatile logging memory or telemetry to relay the altitude information to a remote logging receiver"
It sure is a commercially produced altimeter, it records the flight data and you can view the data on a time vs. altitude graph.
140feet.jpg
So I think this altimeter would be allowed in the WRA2 competitions (I hope it will be allowed because that's why I bought it.)
I'm going to try it in my new rocket within a week.
Wow! That's awesome! I'm interested on this altimeter and I think that i'm will buy it.
PTrockets wrote:
Wow! That's awesome! I'm interested on this altimeter and I think that i'm will buy it.
Some notes before you're going to buy it.
1. The altimeter needs a seperate battery, I use a single cell LiPo battery for this but you can use any kind of battery as long as it's between 3.7V and 8.4V
2. The software and driver don't come with it, you need to download them yourself from: http://www.fd-rc.com/rjxz.asp?boardid=214
3. Getting it to work on Windows Vista and Windows 7 can be a bit of a hassle (but it's possible). If you're on Windows XP, like me, it should be no problem at all.
arjan wrote:The rules say "Rocket must carry onboard a commercially produced recording ("Logging") altimeter to document the entire flight on a Time vs. Altitude Graph to nonvolatile logging memory or telemetry to relay the altitude information to a remote logging receiver"
It sure is a commercially produced altimeter, it records the flight data and you can view the data on a time vs. altitude graph.
140feet.jpg
So I think this altimeter would be allowed in the WRA2 competitions (I hope it will be allowed because that's why I bought it.)
I'm going to try it in my new rocket within a week.
Looks good to me. Altitude vs. time for the entire flight.
Lisa Walker, Forum Administrator. The Water Rocket Achievement World Record Association
DogLover wrote:So altimeters that only record peak altitude are not allowed according to the official rules? That is kind of odd.
They are allowed in the altitude challenge, but that class is probably going to be replaced by the "Pop Bottle Altitude" class.
The reason why they aren't allowed in class A and B:
(coppied from the WRA2 competition rules)
"So-called "Peak Altitude" altimeters are also unacceptable because they are subject to false peak readings caused by external factors such as:
· Recovery system deployment.
· Landing impact.
· Improper installation.
· Unstable flight characteristics."
For the class A and B competitions (also called single stage and multiple stage) It was decided that flights could be compared to the onboard video footage as a further check/verification to validate record. With a "peak" altimeter you would only have the one data point (the max altitude). With the entire flight curve, it can easily be compared to the video.
As far as the other reasons chute deployment can cause sudden changes in pressure where the altimeter senses the barometric pressure. The wind blowing on the sensor hole will cause the pressure to read higher and the altitude lower but if the sensor faces away from the wind the pressure will drop (the air moving over the round rocket body will cause a low pressure at the sensor and thus read higher. Impacts and vibration will also cause false readings. With an entire flight vs. time the bogus values are easily identified and discarded.
It is good to make this clear before a competitor goes out and purchases the wrong type.
I believe that once the rules are drafted for the new pop bottle competition, "peak" altimeters will be allowed in the "unreifnorced" division. What we did for the altitude challenge is require the record be the average of 3 flights in 3 hours as opposed to two flights in two hours for "logging" altimeters. I think that is a good compromise and allows the lower cost altimeters into that competition while accounting for false readings by requiring 1 more flight to average. That requirement would remain for the "unreinforced" division.
Lisa Walker, Forum Administrator. The Water Rocket Achievement World Record Association
PTrockets wrote:
Wow! That's awesome! I'm interested on this altimeter and I think that i'm will buy it.
Some notes before you're going to buy it.
1. The altimeter needs a seperate battery, I use a single cell LiPo battery for this but you can use any kind of battery as long as it's between 3.7V and 8.4V
2. The software and driver don't come with it, you need to download them yourself from: http://www.fd-rc.com/rjxz.asp?boardid=214
3. Getting it to work on Windows Vista and Windows 7 can be a bit of a hassle (but it's possible). If you're on Windows XP, like me, it should be no problem at all.
My HK-A just arrived. I noticed there is a mess of file versions on HK's site. Nice to have this link.
I got my HK-A yesterday. Actually, it's an FD-A relabeled for HobbyKing as the HK-A, but that's another story. I also got 2 key chain cameras (and a couple servos)... downloaded the Win7 (64bit) Driver and the interface software. Install was flawless and only took a few minutes. It took longer to realize I needed to use a Google Search to obtain them than it took to get everything installed. I hooked the battery up and tested it this morning. The base altitude is incorrect (it's in the ballpark, though not exactly correct), but the distance traveled seems to be dead on. I don't know if it can be re-calibrated, but I'm not looking for the exact elevation, just the difference between launch pad and apogee, so I don't know if I'll even bother looking to recal.
I hope there is no wind on my next day off.... I have a few new toys.
.
