From: NathanD
Sent: Sunday, November 09, 2008 10:43 PM
Subject: RE: [arsabq] altimeters

Kevin,


I have used the Transolve P6K, Missileworks RRC2X, ARTS, RDAS Compact, RDAS Tiny, 
Parrot V1, and Parrot V2. Here are my thoughts:


Transolve P6K: This is a baro-only, dual-deploy kit. Sells for $58 including 
shipping. Seemed to work fine, until I crashed it (no fault of the altimeter). 
Had a programmable “Mach delay”. Good cheap option.


Missileworks RRC2X: Baro-only, dual-deploy. Sold for $95. Good quality, very 
reliable. Crowbar circuits on outputs limit current—can fire into a dead short. 
Would recommend Missileworks over Transolve—just seemed more professionally 
done. Good backup altimeter. The RRC-mini replaced this unit, and costs only $80. 


ARTS: Baro plus accel, dual deploy, great interface software, sells for $180 
or so. Great altimeter. Programmable sampling rate, up to 200 Samples/sec. 
Software calculates motor thrust curve and Cd vs V. Telemetry package available, 
but kind of expensive. 


RDAS Compact: Baro plus accel, dual deploy, plus expandable data acquisition 
bus. Has lots of add-ons like telemetry package, GPS, igniter boards, magnetic 
apogee detector, etc. Really fine unit. Seems like the ARTS is patterned after 
this one. Solid, good interface software. This one has been used by the pros—
I believe it flew on the CSXT flight to space. Not sold anymore—replaced by 
the Tiny.


RDAS Tiny: Baro plus accel (2 axis), 4 pyro outputs, plus add-on data acquisition 
bus. Same add-ons as RDAS Compact. This also has been used by the pros—UP Aerospace 
flies it on their Spaceloft XL vehicle. Has flown to space! This one is really 
the pick of the litter, as far as I am concerned. The only drawback: this one 
costs 220 Euros. At current exchange rates, that’s over $300. I believe Wildman 
has distribution rights in the US. USB interface—nice for newer computers. 


Parrot V1: Baro plus accel (2 axis), 1 pyro output (sort of). Tiny and includes 
LiPo battery (9 g total mass). Really great data logger. Holds 5 flights. Each 
flight samples pressure, temperature, acceleration in two directions, and battery 
voltage. Not sold anymore. Replaced by the V2.


Parrot V2: Baro plus accel (2 axis), 3 pyro outputs with screw terminals. Still 
tiny—around 9g including LiPo battery. Need separate deployment battery. Funky 
hookups—since the small size prohibits having all the screw terminals you’d really 
want. Nonetheless, very programmable, with the same great data logging features 
as the V1. USB interface. Spreadsheet processing of data. Clunky Hyperterminal 
interface. Here’s a V2 feature no other accel-based altimeter has: it works with 
either end facing up! Can get a version calibrated to 100k’ MSL. My verdict, 
having only flown this once: quirkiness aside, this is a great little unit. Check 
it out at www.featherweightaltimeters.com. I believe it runs $145. 


My favorite has to be the RDAS Tiny. The Parrot has a lot of “cute factor”. The ARTS 
is a solid choice. Missileworks is good if you don’t care about data.



Hope this is helpful.



--Nathan