Altimeters

[Bret PackardParticipant]

that sounds kinda neat, which units have that capability? I’ll prolly still start with the RRC2x. Seems like you can’t beat that price for a reliable first alti, but I’m a gear geek, so I’ll prolly end up with several eventually (unless the wife takes my CC away :P)

[Warren B. MusselmanModerator]

There is a decent list of good recording altimeters, both barometric and accelerometer based. How fancy you get determines how much you spend.

I have a Perfectflight MAWD – fits a 24mm tube, downloads data to the PC, dual deploy, barometric, mach delay to 18 seconds. Good deal – $125 with computer cable and software.

Others are the Defy Gravity unit, the G-wiz AltAcc, the LokiResearch ARTS unit and many more. If you want to get really fancy, you need to think about a full blow flight computer which the Defy-Gravity unit actually is, the Euro-made RDAS modular unit, and if Jim Amos ever finishes it, the Missileworks MPAC. There are others as well. High Power Rocketry did a full-scale review last year or the year before. Don’t have the issue handy here at work, but worth looking into.

Warren Musselman

[Bruce R. Schaefer]

I have a Black Sky 1010 AltAcc2C , but I haven’t used it yet. Just ground tested it according to its directions. Saving it for L3 with a MWC XRRC2 40k backup. Has anyone else used one of these?

[denverdoc]

Without referring to the issue Warren cited, the biggest bang for buck probably comes down to a choice of three altimeters, possibly four as I’m unfamiliar with the Black Sky gear. I’ve chosen these as they will all easily fit in a 38/54mm tube, have both accelerometer and baro sensors, do data logging and come bundled with software, as well as can be configured to fire 4 to 5 pyro channels, (all below 200).

Defy Gravity (now back in the hands of the developer at Rocketmotion) “Control” is an extraordinarily flexible unit that has “switches” for events such as touchdown which can be used to set off an alarm or via a “tether” cut loose shroud loops.

Ozark ARTS available thru Loki. With bundled software can estimate total N-s of impulse and Cd–great for EX and can support GPS with add-ons.

and G-Whiz MC-2, not as full feaured as its bigger brother, but been around for a long time and just keeps getting better. Believe there is a +/- 100 gee version for extreme flights.

As I said may be more, but this is a short list of of the sweet spot. RDAS, G-WHIZ top of the line, and Jim’s MPAC (when available) are the top of the heap, but all retail for significantly more $$$$. 😯

JS

[Chris LaPanse]

Without referring to the issue Warren cited, the biggest bang for buck probably comes down to a choice of three altimeters, possibly four as I’m unfamiliar with the Black Sky gear. I’ve chosen these as they will all easily fit in a 38/54mm tube, have both accelerometer and baro sensors, do data logging and come bundled with software, as well as can be configured to fire 4 to 5 pyro channels, (all below 200).

Defy Gravity (now back in the hands of the developer at Rocketmotion) “Control” is an extraordinarily flexible unit that has “switches” for events such as touchdown which can be used to set off an alarm or via a “tether” cut loose shroud loops.

Ozark ARTS available thru Loki. With bundled software can estimate total N-s of impulse and Cd–great for EX and can support GPS with add-ons.

and G-Whiz MC-2, not as full feaured as its bigger brother, but been around for a long time and just keeps getting better. Believe there is a +/- 100 gee version for extreme flights.

As I said may be more, but this is a short list of of the sweet spot. RDAS, G-WHIZ top of the line, and Jim’s MPAC (when available) are the top of the heap, but all retail for significantly more $$$$. 😯

JS

I would agree that those are good altimiters, but I would still go with the RRC2 or RRC2X for a first time altimiter. The extra features are nice, but unnecessary, and can only add confusion for a very first altimiter flight. Keep it simple at first, then work your way up.

[Doug GerrardParticipant]

I really try to avoid posting negative comments but I do have to inform you that “Control” failed to work on my 2 stage rocket and all was completedly lost. This is the same rocket I flew successfull at the last Oktoberfest. I chose it because of the “extra” (forth) channel and it could do all, staging, upper stange ignition, and recovery. Although the exact cause of the failure will always be unknown, it did none of those things. Would you like to buy a used one? Flown twice, worked once…

I prefer the MC. I can down load the data and export it into another progam. No other that I know of does that. Plus, I prefer that it can be programmed to deploy some time after apogee. Great for the camera shots.

Doug

[denverdoc]

Doug,

Hmmm. Others swear by them. Odd to have a complete failure with both baro and gee launch detect. We’ll see how mine does at MHM in 2 stage mode. Hopefully better than your experience, 😥 but both stages will have redundant recovery electronics in any event as I have the altimeter curse. Figures I’d buy one that is suspect reliability, tho when it does work, it can do damn near anything including mult events contingent on others with variable delays, etc.
J

[Chris LaPanse]

All I know is that I can (almost) completely guarantee that you won’t loose your rocket John. The RRC2 will work, regardless of whether the control does or not 8)

[denverdoc]

chris,

thats good to hear as I have more time invested in this rocket than the rest of my fleet. Wish i had bought one years ago, I’d be a lot further along in the game. May still do as I need to replace my MAWD, and maybe get one of those picoalts you’re talking about for the skinny-mini stuff.
JS

[Doug GerrardParticipant]

The only thing I can contribute it to is either (1) it never got powered up or (2) it couldn’t satisfy its requirements to continue. My understanding is if you tell it a particular configuration and it doesn’t see it, it says “I’m not going to play” and will not proceed to even detect lift off. Its only status indication is a LED which the rocket was not configured for. (It expects you will mount it to the inside of the body tube only). Yes, I should have used reduncancy or verified it was ready or… Hind sight is always 20/20, I just wanted to share my experience and to say don’t trust unproven designs. Sadly that lesson learned cost me thousands of dollars.

Doug

[Author]

Posts