Altimeters: Thumb Drive Sized - Jolly Logic / Estes / Etc. - Share Your Techniques & Stories.

[lakeroadster]

I just received my 1st altimeter Flight Data Recorder, a Jolly Logic Altimeter Two and have zero experience with these.

Could you folks that have experience with these types of altimeters share:

• how and where you typically attach these to the rocket,
• Your experience with them in regard to how well they have worked,
• how durable you have found them to be.. do they survive hard landings? Lawn darts?
• any tips, tricks, or techniques.

Thanks in advance.

 

[techrat]

Ha! I just got one of these as well, but second-hand. I was going to fly it on Sunday in an Estes Olympus kit, but the high winds that day made me chicken out and leave it in the range box. I did lose one rocket that drifted too far into the rocket-eating trees, but it wasn't the Olympus that disappeared (Olympus had a picture-perfect flight). I've looked at the instructions, and the altimeter is pretty easy to use. Drill holes in your rockets (in the payload bay if you have it), for good readings as it has to read the air pressure. and keep some bubble wrap handy. If you can fly an egg-lofter without making an omelet, the Jolly Logic should survive.

 

[mh9162013]

The JL AltimeterTwo was my first altimeter and it worked well. Two things I noticed.

One, it'll work without the case (and fit inside BT-20 tubes), but it's less durable and won't survived quasi-ballistic recoveries as well...but they should still survive. I had a few Estes Wizard flights where the parachutes didn't fully deploy (think tiny ball of plastic) and the apogee was about 100-150 feet. After these flights, the altimeter would work, but only with the original case installed.

Two, the battery meter has been fickle for me. Whether's fully charged or half charged, the battery % would fluctuate a lot.

I attached mine directly to the end of the nose cone with a snap swivel. Ideally, I'd put it in a payload bay or make a small little pouch for it.

 

[Voyager1]

I attach mine at the nosecone with swivel clip. Make sure you have the appropriate pressure vents in the forward section just below the NC coupler. Using a protective bag is a good idea, or a small wrap of Nomex.

 

[teepot]

I have an Altimeter 3 and a 2. The three stopped working after being dragged across the dry lake bed. A dust storm blew through just after lift off. I would just attach it to the shock cord and let it dangle. From now on I going to not going to let it dangle.

 

[neil_w]

My #1 tip: remember to turn them on.

 

[cerving]

My #1 tip: remember to turn them on.

Good tip for ALL altimeters... especially if they're doing deployments.

 

[dmaaero]

That"s a great idea, an a good project for today. Make a small nomex altimeter case.

 

[bibbster]

I have used a Perfect flite Firefly for a few years now. I attach it to the nose cone via a short length of kevlar line and a swivel. It rides inside a Dinochute protector.

It's a different brand but the use tips apply to the JL version

 

[Antares JS]

I have a dinochutes protector for my AltimeterThree. I put it in the protector mounting loop first and tie it off to the shock cord or parachute shroud lines, making sure the kevlar string goes through both the hole in the protector AND the mounting loop on the altimeter to prevent it from falling out of the protector.

 

[Steve Shannon]

I suspect the single greatest use case of small, non-deployment altimeters is TARC. They are limited to a couple models of PerfectFlite altimeters. They have been included in rockets for many years now without any particular care. I’ve seen them wrapped in cloth and wedged into a payload tube and sandwiched between porous foam.
The PNut has full flight logging.
Beware, they’re sometimes difficult to obtain.

Altimeters

PerfectFlite: Electronics for Rocketry - ...Affordable instrumentation for (sm)all rockets...

www.perfectflite.com

 

[rocketman328]

I just received my 1st altimeter, a Jolly Logic Altimeter Two and have zero experience with these.

Could you folks that have experience with these types of altimeters share:

• how and where you typically attach these to the rocket,
• Your experience with them in regard to how well they have worked,
• how durable you have found them to be.. do they survive hard landings? Lawn darts?
• any tips, tricks, or techniques.

Thanks in advance.

View attachment 554343

These are really miss named, its really a flight data recorder. The Alt2 is easy to use and seems very durable, I use the snap in mount available from JL.

 

[BEC]

Since you also mentioned the Estes device (which is essentially a reverse-engineered first-generation AltimeterOne), most of what is said above applies to it as well. It is more finicky about detecting a launch, though I have yet to successfully figure out exactly why. It gives good results if you get a reading (and you don't expose it to lower pressure after a flight, as it does not lock in an apogee ever.

AltimeterTwo and Three use the accelerometer for launch detect, so are less fussy about static port size, but it is good to have some, dedicated payload compartment or not.

 

[dr-ws]

I just received my 1st altimeter Flight Data Recorder, a Jolly Logic Altimeter Two and have zero experience with these.

Could you folks that have experience with these types of altimeters share:

• how and where you typically attach these to the rocket,
• Your experience with them in regard to how well they have worked,
• how durable you have found them to be.. do they survive hard landings? Lawn darts?
• any tips, tricks, or techniques.

Thanks in advance.

View attachment 554343

May I suggest:
1. Read Mr. Beans' manual through multiple times.
2. Unless you did not pay the $70 that I did, don't count on a cheap swivel - use appropriate Kevlar to a metal or Kevlar anchor (mine is usually tethered inside of or near the base of my nose cone) - not a snap swivel. Use good knots.
3. TURN IT ON just before inserting your igniter - be aware a wind gust on the pad may be enough to trick the device into believing it's been launched, too.
4. Don't, as I did, count on the Dinochutes protector. While helpful, it wasn't enough to keep my Alt. Two's LCD from interacting with an internal piece of metal (a screw eye?) under acceleration, making data collection from a very nice flight unobtainable, even once I'd replaced the LCD. I now add bubble wrap, foam, or use JL's snap-in mount to protect the device.
5. Yes, it's durable, thanks to its polycarbonate case (don't remove it just to fit a BT-20 airframe - get a PNut altimeter for that!).
6. DO add (usually three, at 120 degrees around the airframe's circumference) static ports (holes) to compensate for changes in air pressure in and out of the rocket on its way to apogee.

Ownership of these devices inspired me to develop an Excel spreadsheet on (in?) which to record all my flights, including all data obtained (from those flights that allow use of the Altimeter Two) from my devices. The Fun Factor has increased substantially from the flights of my youth where we'd guess (!) altitude, or succumb to the tracking of quasi-vertical flights via large-error single protractor-assisted homemade theodolites. Just wish Altimeter Two had been available back then to stuff into those B14 flights. . .

 

[Rocketclar]

I just received my 1st altimeter Flight Data Recorder, a Jolly Logic Altimeter Two and have zero experience with these.

Could you folks that have experience with these types of altimeters share:

• how and where you typically attach these to the rocket,
• Your experience with them in regard to how well they have worked,
• how durable you have found them to be.. do they survive hard landings? Lawn darts?
• any tips, tricks, or techniques.

Thanks in advance.

View attachment 554343

I use 100 pound nylon cord and attach the altimeter to the NC in a vented payload bay for low/mid power flights using a loop method. Seems to work. One caution: remove the NC very slowly. One time I removed it too fast and saw the altitude change on the Estes altimeter! I had pulled too big of a vacuum too quickly.
Rugged; however, most of the time they ride in a small, vented (3 holes) bay.

 

[BEC]

I use 100 pound nylon cord and attach the altimeter to the NC in a vented payload bay for low/mid power flights using a loop method. Seems to work. One caution: remove the NC very slowly. One time I removed it too fast and saw the altitude change on the Estes altimeter! I had pulled too big of a vacuum too quickly.
Rugged; however, most of the time they ride in a small, vented (3 holes) bay.

As I noted in my post above, the Estes altimeter never locks in an apogee. That is not true of the Jolly Logic devices. After a short period of time of the altitude not changing (info in the manual, I don’t remember the number right now), they will lock in the apogee reading.

3. TURN IT ON just before inserting your igniter - be aware a wind gust on the pad may be enough to trick the device into believing it's been launched, too.

Not correct for AltimeterTwo or AltimeterThree as they use their accelerometers for launch detection. However, don’t drop the rocket on the way to the pad…or down the rod/rail. Barometric-only altimeters are subject to this in varying degrees, though most anything you can buy now has pretty good software to figure out when/whether it’s flying or not. This is also a reason not to use just one vent hole in the compartment where the altimeter is riding.

5. Yes, it's durable, thanks to its polycarbonate case (don't remove it just to fit a BT-20 airframe - get a PNut altimeter for that!).

Or a FireFly. For either one there is no room to wrap any protection (save maybe a sheet of wadding) around them in BT-20. Pictures showing Pnut and FireFly in a piece of PST-20.

6. DO add (usually three, at 120 degrees around the airframe's circumference) static ports (holes) to compensate for changes in air pressure in and out of the rocket on its way to apogee.

YES!

Ownership of these devices inspired me to develop an Excel spreadsheet on (in?) which to record all my flights, including all data obtained (from those flights that allow use of the Altimeter Two) from my devices. The Fun Factor has increased substantially from the flights of my youth where we'd guess (!) altitude, or succumb to the tracking of quasi-vertical flights via large-error single protractor-assisted homemade theodolites. Just wish Altimeter Two had been available back then to stuff into those B14 flights. . .

Indeed. I have hundreds of altimeter flights now and just keeping all of the data straight is a project….

 

[dr-ws]

Not correct for AltimeterTwo or AltimeterThree as they use their accelerometers for launch detection. However, don’t drop the rocket on the way to the pad…or down the rod/rail. Barometric-only altimeters are subject to this in varying degrees, though most anything you can buy now has pretty good software to figure out when/whether it’s flying or not. This is also a reason not to use just one vent hole in the compartment where the altimeter is riding.
I have experienced several "false launch" records on my Altimeter Twos, all (3? 4?) on rather windy days. What, then, occurred? (Dropping and rough handling did not.)

Or a FireFly. For either one there is no room to wrap any protection (save maybe a sheet of wadding) around them in BT-20. Pictures showing Pnut and FireFly in a piece of PST-20.
Thank you for reminding me of the FireFly, of course! (Nicely photographed.)

Indeed. I have hundreds of altimeter flights now and just keeping all of the data straight is a project…

I only keep mine on Excel (backed up!) due to the prodding of my sister, who helped me set it up. This dinosaur would have been happy to save it in a logbook. Now, however, I am more easily able to do data analysis, should I so choose. I'll probably just fly, however.

 

[BEC]

I have experienced several "false launch" records on my Altimeter Twos, all (3? 4?) on rather windy days. What, then, occurred? (Dropping and rough handling did not.)

I don’t know what to tell you…..that would be a question to bounce off of the rather-hard-to-find-these-days @John Beans I guess. Sorry. The only thing I can think of is if your model got jostled around on the pad by the wind on those occasions. But John would have to tell both of us for sure what the likely trigger was in those cases.

Thank you for reminding me of the FireFly, of course! (Nicely photographed.)

You’re welcome. I just grabbed the tube and one each of the two altimeters and set them down here on the desk next to the keyboard for the iPad and took pics with my phone, then cropped before posting.

BT-20 tubes are a challenge for all but the competition-centric altimeters such as the Adrel ALT-BMP (or as North Coast calls it, the MaxAlt) or the currently unavailable FlightSketch Comp. Either of them are small enough that they can be provided with some protection from ejection charges in a BT-20-based model. But I prefer a dedicated payload section in stuff that small and have a Viking and a Checkmate so modified. Then a FireFly or an FS Mini (still hoping they are available again soon) or a MicroPeak will also work without having to worry about eventually ruining them with ejection gasses.

I only keep mine on Excel (backed up!) due to the prodding of my sister, who helped me set it up. This dinosaur would have been happy to save it in a logbook. Now, however, I am more easily able to do data analysis, should I so choose. I'll probably just fly, however.

Yeah….some of my data is in paper logs. But AltimeterThree keeps a database on whatever device you read it from and easily exports it to a spreadsheet so I have a couple hundred flights’ worth of data in that form (well, there are 277 on my iPhone right now). FlightSketch has an online log where at least one can go to peruse prior flights. I probably have more flights‘ data there than anywhere else at this point, and probably more flights in that log than anyone else.

 

[dr-ws]

I don’t know what to tell you…..that would be a question to bounce off of the rather-hard-to-find-these-days @John Beans I guess. Sorry. The only thing I can think of is if your model got jostled around on the pad by the wind on those occasions. But John would have to tell both of us for sure what the likely trigger was in those cases.


You’re welcome. I just grabbed the tube and one each of the two altimeters and set them down here on the desk next to the keyboard for the iPad and took pics with my phone, then cropped before posting.

BT-20 tubes are a challenge for all but the competition-centric altimeters such as the Adrel ALT-BMP (or as North Coast calls it, the MaxAlt) or the currently unavailable FlightSketch Comp. Either of them are small enough that they can be provided with some protection from ejection charges in a BT-20-based model. But I prefer a dedicated payload section in stuff that small and have a Viking and a Checkmate so modified. Then a FireFly or an FS Mini (still hoping they are available again soon) or a MicroPeak will also work without having to worry about eventually ruining them with ejection gasses.


Yeah….some of my data is in paper logs. But AltimeterThree keeps a database on whatever device you read it from and easily exports it to a spreadsheet so I have a couple hundred flights’ worth of data in that form (well, there are 277 holy s&%#! on my iPhone right now). FlightSketch has an online log where at least one can go to peruse prior flights. I probably have more flights‘ data there than anywhere else at this point.

Dinosaurs don't have iPhones [yet], so no Altimeter Three.
BTW, I have had two interactions with Mr. Beans. Both demonstrated (to me) that he is extremely helpful and more than fair, as well as kind. I hope those attributes have not been the reason he has less time with which to interact with us (other people's demands on his time), but I suspect that to be the case, unfortunately. Selfishness (??) sometimes is necessary to increase one's quality of life in the 'wake' of success, darn it! Kind people seem not to know how to say 'no'.
Incidentally, I've had a back-of-mind thought to modify (or create) a [preferably biodegradable] device that would comfortably fit a BT-20, somewhat akin to a shotshell's wad-with-shot-cup, whereby the wad area acts somewhat as a piston, and the shot cup component insulates the altimeter (or recovery device, or whatever) from ejection sequelae. Or has someone already done that? (And no, not PML's piston ejection system [with which I've actually had much success, including my L2].)

 

[Jean-Pierre]

I like to make my own Arduino altimeters - that way my pocketbook doesn’t hurt so badly when my rockets get eaten by the trees. Very bare bones, but a cheap way to know how high your rocket got, and fun to put together. Happy to share the code/wiring with anyone who might be interested.

 

[mh9162013]

I like to make my own Arduino altimeters - that way my pocketbook doesn’t hurt so badly when my rockets get eaten by the trees. Very bare bones, but a cheap way to know how high your rocket got, and fun to put together. Happy to share the code/wiring with anyone who might be interested.

How much does that cost you?

 

[Jean-Pierre]

How much does that cost you?

Each one requires an ATTiny85, a socket connector for the chip, a BMP 280, a cr2012 battery holder, and an SSD1306 OLED. Looking at Amazon right now, those parts seem to run about $10 or so (prorated for 1 each). I had the PCBs made for like $1 apiece, which is also probably a good estimate for the perfboard/wires I used early on. And the battery is about a $1. The only other cost is solder. So I'd safely call it "under $15," depending on how costs fluctuate and how often I screw up the soldering and break a component.

For fun, I call it the TinyTimeter, both because it uses an ATTiny and because my favorite rocket is the WAC Corporal and its Tiny Tim booster. I used to have it record flight time, too, but I couldn't get it very accurate, so I scratched it from the code.

 

[Blast it Tom!]

Each one requires an ATTiny85, a socket connector for the chip, a BMP 280, a cr2012 battery holder, and an SSD1306 OLED. Looking at Amazon right now, those parts seem to run about $10 or so (prorated for 1 each). I had the PCBs made for like $1 apiece, which is also probably a good estimate for the perfboard/wires I used early on. And the battery is about a $1. The only other cost is solder. So I'd safely call it "under $15," depending on how costs fluctuate and how often I screw up the soldering and break a component.

For fun, I call it the TinyTimeter, both because it uses an ATTiny and because my favorite rocket is the WAC Corporal and its Tiny Tim booster. I used to have it record flight time, too, but I couldn't get it very accurate, so I scratched it from the code.

Wow! Now I just lurve me my Flightsketch mini, and hopefully they can soon (if they haven't already) got their supply problems fixed. I'm surprised this one hasn't been mentioned yet, maybe that's the reason, but for $30 or so you get quite a wealth of data - though I can understand wanting to "do it yourself". I'll admit to having done some real time coding a long long time ago, and it would be great to DIY as you have - I just don't have time to re-grow that ability! It's all I can do to finish a rocket!

 

[dmaaero]

I got my "flight data recorder" pouch made,
Thanks @mh9162013 for the idea.

 

[BEC]

Wow! Now I just lurve me my Flightsketch mini, and hopefully they can soon (if they haven't already) got their supply problems fixed. I'm surprised this one hasn't been mentioned yet, maybe that's the reason, but for $30 or so you get quite a wealth of data - though I can understand wanting to "do it yourself". I'll admit to having done some real time coding a long long time ago, and it would be great to DIY as you have - I just don't have time to re-grow that ability! It's all I can do to finish a rocket!

I did mention the FS devices a few posts back but since the OP was asking specifically about the Jolly Logic and Estes devices, I tried (unsuccessfully) to stick to that subject. No point in promoting them until Russ @gtg738w is able to make some more. He's gone radio silent on me again, unfortunately. I had an odd set of data on January 1st that I'd love his opinion on (and about which I wrote to him).

 

[John Beans]

I have experienced several "false launch" records on my Altimeter Twos, all (3? 4?) on rather windy days. What, then, occurred? (Dropping and rough handling did not.)

Although AltimeterTwo *tries* to ignore normal handling, it's not perfect, so false launches can occur. But BEC's correct—AltimeterTwo detects launch using its accelerometer, NOT the pressure sensor. So false launches are the result of dropping/shaking/moving, not the wind (unless the wind caused those kinds of movements). Most of the time I think it's the drop down the rail/rod that does it, but that's just speculation on my part.

And AltimeterThree just records everything, no launch detecting involved.

 

[BEC]

Although AltimeterTwo *tries* to ignore normal handling, it's not perfect, so false launches can occur. But BEC's correct—AltimeterTwo detects launch using its accelerometer, NOT the pressure sensor. So false launches are the result of dropping/shaking/moving, not the wind (unless the wind caused those kinds of movements). Most of the time I think it's the drop down the rail/rod that does it, but that's just speculation on my part.

And AltimeterThree just records everything, no launch detecting involved.

John — thanks for surfacing from whatever has been keeping you away and setting the record straight. Happy New Year! I will remember that A3 really doesn't need to do a launch detection since, after all, it starts recording when you tell it to.

 

[BEC]

I like to make my own Arduino altimeters - that way my pocketbook doesn’t hurt so badly when my rockets get eaten by the trees. Very bare bones, but a cheap way to know how high your rocket got, and fun to put together. Happy to share the code/wiring with anyone who might be interested.

That actually looks good. I've only played with Arduino-based things a very little bit — mostly the project that Bruce Canino and @WillMarchant did for vNARCON last year. I am most interested in whatever filtering you do in the calculated altitude data to account for the device getting shaken up by the events around ejection and other sources of noise (see the discussion about "funnies" in MicroPeak data just above). In my experience with hundreds of altimeter flights, that's where the makers of the devices have the biggest challenge, and why I've never really tried to "roll my own".

 

[Blast it Tom!]

I did mention the FS devices a few posts back but since the OP was asking specifically about the Jolly Logic and Estes devices, I tried (unsuccessfully) to stick to that subject. No point in promoting them until Russ @gtg738w is able to make some more. He's gone radio silent on me again, unfortunately. I had an odd set of data on January 1st that I'd love his opinion on (and about which I wrote to him).

Well, I thought I scanned the thread well but must've missed your mention. I sure hope Russ is able to restart production, for me this is a beautiful little piece of work for the LPR world. I'm planning to include (vented) payload areas or some other construction in all future builds, so as to avoid the ejection spike issue.

 

[Jean-Pierre]

That actually looks good. I've only played with Arduino-based things a very little bit — mostly the project that Bruce Canino and @WillMarchant did for vNARCON last year. I am most interested in whatever filtering you do in the calculated altitude data to account for the device getting shaken up by the events around ejection and other sources of noise (see the discussion about "funnies" in MicroPeak data just above). In my experience with hundreds of altimeter flights, that's where the makers of the devices have the biggest challenge, and why I've never really tried to "roll my own".

Thanks! I didn't include data filtering, so my altimeters are still vulnerable to the "funnies." But FWIW, I haven't seen any really wild readings; and when I've flown with a transceiver, the data have made the flight curve you'd expect (once you smooth it out, I mean).

I'm also not sure whether data filtering routines could fit on an ATTiny - the memory on an ATTiny is small, and printing to an OLED eats up a lot of it. Could try upgrading to an ATMega, but the physical size of that chip is a problem unless you can use the surface mount version - and that exceeds my very limited soldering ability.

Regardless, good idea if I can ever figure out the code. Fun to keep tweaking the code and making improvements.