Dual Deploy / Logging Altimeter Preferences from Experience

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Donnie

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All--

I'm looking to purchase a logging, dual-deployment altimeter. From your personal experiences, which would you recommend from the following, and why? Software interfaces, ease of wiring layout in a bay, data acquisition rate, customer support, failure rate of deployments directly related to the altimeter, etc. are all things I'm interested in hearing about. Here's my short list:

*PerfectFlite Stratologger CF
*Altus Metrum Easy Mini
*Missile Works RRC3
*Eggtimer (i'm fairly comfortable with soldering, etc)
***LATE ADDITION: Featherweight Raven 3

I don't currently have any dual-deploy rockets, but I'm wanting to move in the direction over the next several months as I start looking at my Level 1 cert. I do want a logging altimeter that I can use for my current rockets in the interim, so something that would fit into a BT-60 (for an FSI Megatron) or perhaps even a BT-50 for a Quest Payloader One.

A friend and I also plan to begin working on a home-built flight computer in the near future, so this purchase will also be something we can use as a benchmark and as backup during development.

I'm also open to other options in this general price / size range.

Mainly wanting to have some idea(s) in my head of what I want, so that I can capitalize on Yard Sale / Black Friday deals, should they come along.

Thanks in advance!
 
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Either the Stratologger or RRC3 would make an ideal first step. I have used both product lines for years and have no complaints with either.

Note: I know nothing about the Easy Mini and the need to assemble SMC (unless you want to pay Connor - which I did) leaves you at the mercy of your skills.
 
I have limited experience; however SLCF has worked great for me...so much so that I've just ordered another. I also love that the new ones have an audio port with larger speaker option (can replace a beeper/sound locator).

Eggtimer support is great; however the product really depends on the assembler. :wink:

Can't speak for the rest.
 
I do not have experience with the other three, but I believe the RRC3 is in a class of its own among this group. I base this on the programmable auxiliary channel. I use the aux channel on almost every flight for a secondary main charge. It does more than that, and I recommend you read the manual and look at its capabilities.
 
I've used Stratologger CFs on 7 flights this year and they've worked perfectly. I had an eggtimer quark on two of those for a backup and it worked flawlessly too. Hard to beat the quark for $20. If it recorded data I'd throw a pair of them in every flight. I've built 4 quarks and they all functioned in the vacuum chamber. Out of 10 eggtimer kits I've built the only defect I've found was a cracked resistor on a quark during the vacuum chamber check that was easy to identify and replace. Cris sends spare resistors with his kits.
 
Thanks, all, for your input thus far. Man, this is SUCH a slippery slope, lol! It's hard to draw the line... now I'm also adding to the list the Raven 3. It's roughly twice the cost of the other alternatives in my initial list (when you include the adapter cables as required for some manufacturers), but the higher DAQ rate, the added pyro channels and the addition of accel data really put it at yet another level, for roughly half the cost of some of its apparent peers.

So... does that change anyone's opinion?

Thanks!
 
I'm a fan of the RRC3 myself, and soon it will have the RTX gps module to go with. Another option would be the Eggfinder TRS a complete system gps tracking and deployment for only $140. But for ease of use and functionality the RRC3 is an excellent choice.
 
Wow, lots of rrc3 and stratologger cf fans around here. Good stuff, this is the info I was looking for. Sometimes having commonality on the field is worth quite a bit (at least in the fireworks world... I don't see this being a lot different). Thanks again!
 
Wow, lots of rrc3 and stratologger cf fans around here. Good stuff, this is the info I was looking for. Sometimes having commonality on the field is worth quite a bit (at least in the fireworks world... I don't see this being a lot different). Thanks again!

Probably because they both are good values for the functionality they contain.
 
I've flown StratoLoggers (SL100 and SLCF) as well as an EasyMini and an Eggtimer TRS (haven't used the non-TRS version). I like them all, and for basic DD I think any of them will do the job just fine.

In my 4" rocket I fly redundant altimeters, a SLCF and an EM. I found it a bit easier to program the EM via its software, so I left the SLCF as the 'primary' configured for its default apogee and 700' main, and tweaked the EM to a 2s delay on the drogue and 600' on the main. It is nice that you can simply use any USB micro-B cable with the EM, the StratoLogger's data cable isn't particularly inconvenient but it is less-standard. I've had no charge firing issues with any of the SL100/SLCF's I've used or the EM. I used only magnetic switches for activation and they've always turned on/off without any firing issues.

I do like the SLCF's loud speaker and the extra data it gives using it. When you power-up the EM it simply beeps-out the battery voltage and goes straight to continuity beeps. The SLCF (and SL100) beep out their mode (which gives a basic indication of drogue/main settings), the main altitude setting, and the last flight's peak altitude, then battery voltage and continuity beeps. Similarly, at landing the EM gives out some beeps though I haven't figured out if they really mean anything (the manual makes no mention of anything other than the landing phase beep), the SLCF beeps out the max altitude and max velocity, AND periodically makes a pretty loud 'warble' that can help lead you to the rocket which I really like. The SLCF's beeper is much louder than the EM's also. Between the two I like the SLCF better for what it does 'out of the box', while the EM seems a bit more user-friendly to me on the configuration and data download (the app has a bit more fit & finish, on the Mac at least).

I flew the TRS in a rocket where I wanted both deployment and tracking in the nose (the other rockets have dedicated e-bays and Eggfinders in their noses). The tracking part works great and configuring it via the LCD unit or serial is pretty easy, I never really did get what I wanted with the deployment part, though I wasn't doing simple e-matches like the other altimeters. I wanted to use a hot-wire cable-cutter, but had lots of trouble getting the TRS to output enough current to actually get the wire hot. While dialing-in the nichrome resistance I managed to fry the transistors on the board more than once also (fortunately they're easy to replace). I wound up cutting a piece of copper to put under the transistors for extra heat-sinking and dialed the resistors in to get the right current to get the wire temp I wanted, but the activation time just wasn't long enough to reliably burn through even the tiny zip ties I was using. I had no trouble melting the zip ties using my SL100, I just didn't have space in the nose for both a tracker and an altimeter (and batteries for each). That rocket is in need of a rebuild now (an RMS-EZ early motor eject did it in), I'll go to a more conventional DD with a proper e-bay, I may keep the TRS in the nose just for tracking and an additional flight logger, maybe a backup charge for the main. Not sure whether I'll put another SLCF or EM in this rocket's e-bay, I might lean slightly towards the SLCF. The TRS is also really handy for ground testing since you can fire the charges remotely using the LCD unit, so I've moved it from rocket to rocket specifically for ground testing even if that's not the altimeter I normally use in that rocket.

Data-wise, I find the TRS flight log the 'glitchiest', for example it tends to have trouble with both lift-off and motor burn-out on my rockets (the AltimeterTwo has had similar issues with burn-out on the same rockets), I didn't see any ascent issues with the SLCF or EM. At apogee during separation I have seen some fairly wild readings from the SLCF (the altimeters are well-isolated from the actual charges), the EM seems more stable in that regard. The velocity filtering done by the SLCF is a bit odd, it often reports the top speed ~0.5-1 seconds after burn-out, and touchdown gets a bit funky also. The SLCF records at a constant 20Hz the entire flight, the EM is 100Hz up to apogee then 10Hz from then on to save on storage space. The TRS is 20Hz to apogee then 2Hz down for the same reason. The EM adjusts its log timing such that liftoff is at T=0 with some ground data before (the TRS also seems to adjust but has no data before T=0), the SLCF captures some fixed number of samples before its launch-detect but the first sample is called T=0, which generally means lift-off occurs around 0.4-0.6s in my logs (not that adjusting all of the times in the final spreadsheet isn't a fairly easy task). Correlation on max velocity and apogee (once removing any obviously-bogus readings from the more glitchy ones) has been good between all of these altimeters (as well as with altitude on the AltimeterTwo and AltimeterThree and velocity readings on the A2 when it doesn't report totally bogus values).

Support-wise, the Eggtimer Rocketry has been great, Cris is very helpful both on email and in this forum. I've gotten pretty good support from Altus, and I haven't had much luck getting my emails answered by PerfectFlite. While the AltimeterTwo/AltimeterThree are not deployment altimeters I will say that Jolly Logic's support has also been great.

So from my experience so far, I'd probably rate the SLCF just a tiny bit above the EM, and the TRS not far behind (and also having tracking in the TRS is a huge plus for space-constrained rockets). None of these have accelerometers which I miss, I tend to fly an AltimeterTwo and/or AltimeterThree in these rockets to get accelerometer data as well. I'm thinking about moving up towards an altimeter that can do airstarts, and I'm really tempted to go with either the EasyMega or the TeleMega (if I decide to go for a HAM license as well, getting the real-time feed into the Altus software looks like it could be pretty sweet).
 
At 80$ the Easy Mini is hard to beat. Very simple to operate and download. It will also fit in a 24mm frame. You might consider ordering one of Cris Eving's kits like the new WiFi switch and give soldering a try. The kit is only 20$. The other option would be to try the Quark deployment altimeter. It does not record full data but it can be used as an excellent backup altimeter. It is only 20$ as well. Look at it this way, if you mess up a 20$ kit you will still learn something. Plenty of tips and video links on other threads.
And finally, consider the Altus Micropeak altimeter used in conjunction with a non recording deployment altimeter. This is a great combo for small rockets.
Sometimes it is better to start small and simple and work your way up the the other products.
 
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The other option would be to try the Quark deployment altimeter. It does not record full data but it can be used as an excellent backup altimeter.

+1 Combined with the SLCF as a main, I think the Quark is a great for a redundant first DD system. Reliable and cost effective. I haven't had the chance yet to set up the redundancy (sometimes KISS overrules redundancy), but have tested it several times with live charge ground tests and it worked well enough for me to feel it would be a great backup.

I do plan on getting an ET TRS down the road after having assembled the Eggfinder LCD (which I enjoyed a lot) and finding it a great locator system for my needs & field...if it can save hours of searching a field or give you extra peace of mind, it's already earned it's coin.
 
I have all these Altimeters. .but not the AM Easy Mini.

The RRC3 and the Raven interface programs are both 'Windows Only' based on net services. I have not tried the SL CF hooked to the computer yet because I didnt buy the cable.

I bought the Raven 3 first as it 'was the best' 'does everything' 'small, and has accessories ' . In the field I found that it was inconvenient to shuttle back in forth because of the wiring and the #2 size holes for mounting. And the biggest detriment to flying was i dodnt want to lose it.. 4 inch fg rocket.. no problem. . Daughters mini eagle claw that teleports outta sight on a G motor .. no way !

I hold the SL CF and the RRC3 equal in ease of mounting, wiring and use.. anymore i almost dont bother hooking up to computer anymore. Nod to SL CF for being half the size and being priced stellar.

Now to the eGG stuff. Have built the eGGtimer and the Quark. Both like the RRC3 and Raven allow you to test deployment .. but the Quark (and TRS) is the only one that allows the test WITHOUT being hooked to a computer. If you do an eGGtimer the sled wiring is a little more involved because of the independent battery options . The Quark is easy .. but has #2 holes..but is cheap enough to mount and dedicate to a sled so a non issue.

CF and Quark are great because of size you can use them as backup altimeters ..they will always get used !

Kenny
 
If you are careful you can run a #4 tap through the #2 holes on the Quark and use #4 screws. I don't know if you can do this on other boards.
 
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