# Small cheap reliable altimeter

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#### AtomicStorm

##### Well-Known Member
I have been building basic rockets for a while now and would like to start learning more about altimeters and onboard electronics. I would rather do the research and build my own electronics (and everything else in the hobby) for less money then just buying them completed. Working on a camanchee 3 kit now, so it has to be less than 25mm(.98"in.) in width. I looked at the estes altimeter and i think its too big, plus im sure i could find something smaller and cheaper. Any ideas?

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#### rharshberger

##### Well-Known Member
The Estes altimeter is pretty unreliable but iirc it does fit a BT50 tube (Comanche 3 is BT50). I would look into the Perfect flight Firefly for altitude only or even better the Flightsketch Mini as it does logging and acceleration data . The FS Mini and Firefly are both priced near the Estes Altimeter in price but are magnitudes more reliable. Cheapers is harder to find but the Eggtimer Quark does altitude with dual deployment but no logging of data, the Eggtime also requires soldering as all Eggtimer products are kits, for apogee only deployment Eggtimer offers the Eggtimer Apogee.

#### boatgeek

##### Well-Known Member
If you want to log data, an Eggtimer Quantum (requires assembly) or a Perfectflite Pnut are also good choices. The Quantum will also do dual deploy and air starts.

#### hball55

##### Well-Known Member
I prefer the Missile Works RRC2+

#### neil_w

##### Good at some things
TRF Supporter
This hobby is starting to add up quick. If i spend $20 on a airframe, idc if i lose it. But once i add$30 in alt., then i need to insure it with another $100 in gps. There has to be a more cost effective way. Trackers are great, but I don't most people would consider recovery of a$30 altimeter to be motivation to use one. Especially on smaller rockets you don't want to load them down with too much electronics. Throwing in an FS Mini or a Firefly into an LPR rocket is pretty easy, and not worth sweating over. Also remember that trackers fail and rockets are lost anyway.

At some point you have to be accept the possibility that you're gonna lose stuff, even while taking all reasonable precautions against that happening.

##### I don't do spirals
TRF Supporter
I have FS Minis in every rocket I fly, plus a few spares (never know when they'll be in stock) Read what neil said above

#### kevin.mcgee

##### Member
TRF Supporter
Altrus Metrum EasyMini

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Which altimeter you choose often comes down to what kind of data and other features you are looking for. That's why there are so many of them, with different features: deployments, datalogging, wireless, telemetry-capable, airstart-capable, GPS-capable, etc. Look at the "Altimeter Comparison Chart" at the top of this section, that might help you... although some of the altimeters are now OOP, and it doesn't have some of the non-deployment altimeters.

#### rklapp

##### NAR# 109557
TRF Supporter
I'm tired of having over-stable rockets lawn dart or zipper on windy days; apogee deployment mitigates most of the risk.
How does it mitigate?

IIRC, the Firefly has beeps but no data logging like the FS Mini.

#### BEC

##### Well-Known Member
Firefly has an LED - it blinks out the digits rather than beeping them. With the Field Data Display you can get some statistics, but not full flight data.

#### neil_w

##### Good at some things
TRF Supporter
How does it mitigate?
A non-vertical trajectory caused by excessive weathercocking will reach apogee earlier than expected, and therefore motor eject is likely to be late, maybe very late.

Apogee eject ensures optimal deployment regardless of the flight trajectory. However, electronic deployment is not really an appealing option for us LPR flyers.