# How many altimeters does one man need?

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#### tHoagland

##### Rocket Builder
TRF Supporter
A couple of months ago I started building small model rockets with my son's cub scout pack and became interested in the hobby. Since then, I've successfully gotten my level 1 certification (dual deployed 4" cardboard Mad Cow DX3) and have continued to build. After this morning's visit to the Mad Cow black Friday sale, I have 3 dual depoy rocket kits in my pile and a couple new altimeters. This got me wondering how others handle their altimeters (flight electronics).

Do you buy an altimeter for every rocket?
Do you swap the electronics between rockets? If so, do you swap the whole AV bay (assuming same diameter) or just the electronics?

It seems to me that reusing the electronics between multiple rockets could help stretch your rocketing dollar, but is it worth the effort?

#### dixontj93060

##### Well-Known Member
I personally have a dozen. Certainly not one for every rocket (although with prices lowered so much in the past decade, you certainly could). Also, I don't swap av-bays, but I will swap av-sleds, especially now with the nice 3D printed sleds available in the marketplace. The reason for so many altimeters really comes down application specifics... On some high performance flights I prefer extra assurance of a accelerometer reading. Also some higher end altimeters provide more data for characterization of research motors. There is also the size and redundancy discussion--if doing small, minimum diameter I nearly always go Raven because it gives me four outputs to implement some level of charge redundancy. But the biggest reason of having multiple types per manufacturer is to cover all flights in one day, i.e., I don't want four or five flights and having to move electronics in a single day, thus I have found that having two to four altimeters per type cover my daily needs fully, and if not, I just shift my flight plans to align with electronics availability.

#### Coop

##### Well-Known Member
I have a Telemetrum which I definitely swap between rockets --it's too pricey to buy a new one for each project.

I also have a Raven 3 which I've swapped between a few rockets where I need (relative) the extra outputs, acellerometers, or due to space requirements.

Often, I'll just get another RRC3 and figure it in the product budget...

Later!

--Coop

#### JohnCoker

##### Well-Known Member
TRF Supporter
At least one per rocket you need to prep for the same launch. I don't like to switch electronics in the field because everything is harder to do out in the desert.

#### jd2cylman

##### Still not Carl... ;-)
TRF Supporter
Phfftt... Lightweights... :wink: I have around 15 or 16. Not really sure now. I've lost count... Mostly Missileworks, a couple of Stratologgers, a MARSA 54, and an old Olsen which I have to try out one of these days...

#### cerving

TRF Supporter
You can buy a Quark for $16 during our Holiday Sale right now, so there really isn't any reason not to have one for every rocket. They're cheaper than motor retainers... and certainly cheaper than motor cases. #### MaxQ ##### Tripoli 2747 Acquired these over the years in this chronology: -Adept Alts2 -G-Wiz LCDeluxe 800 -G-Wiz LCX -Blacksky AltAcc2A -Ozark Arts2 -Perfectflite -Missileworks RRC2-mini -Xavien X-FIST My certs were done with the same Adept Alts I've used since getting into the hobby. I tend to use that most often as it is reliable and easy to use....that and the GWiz - since it can do both airstarts/cluster and staging. Don't like switching out av bays in he fieid - so I usually prep three rockets using seperate altimeters, the other flights the same day are usually apogee deploy or RC rockets that don't need a DD/altimeter. Thinking about getting more modern stuff.....Stratologger looks interesting. Last edited: #### markkoelsch ##### Well-Known Member Phfftt... Lightweights... :wink: I have around 15 or 16. Not really sure now. I've lost count... Mostly Missileworks, a couple of Stratologgers, a MARSA 54, and an old Olsen which I have to try out one of these days... Adrian Adrian , that is whacky, but I like it. I personally have five. An old school Missileworks RRC2 rev C that just works, two RRC2+, an RRC3, and a Mission Control that I want to fire up and use one of these days. Planning on picking up either another rrc2+ or rrc3. May also pick up an egg timer quantum- see if I can remember how to solder. For those who have not been around for more than 5-10 years please realize that the era we are in is fabulous for rocket avionics. The combination of capability and cost is amazing. The Missileworks and Perfectflight stuff is great, and significantly less expensive than comparable devices of the past. Eggtimer stuff looks good too if you want to build yourself. The higher end stuff like the Raven, Marsa, and Altus Metrum stuff is stuff that could not be touched 10 years ago unless you could do it yourself, or had a lot of cash. #### jd2cylman ##### Still not Carl... ;-) TRF Supporter I should do a count sometime. I just bought another RRC3 from Tim's Wednesday sale... I'll probably get another RRC2+ or 2 from Jim's sale, too, just because... I'm not sure how many RRC3's and 2+'s I actually have now. At least 6 of each I think. Maybe I don't want to count... #### dixontj93060 ##### Well-Known Member Adrian, Don't count! If you do, you'll end up being one short and you'll rack your brain trying to figure it out. Happened to me last week when I was working on av-bays. Noticed a missing CF. Finally found it last night in the nose cone of my BSD Sprint which I didn't get around to flying at MWP. Also I still have an RRC3 MIA. It was "sick" and so brought it to my office to put a note together to Jim A., but now not seeing it anywhere. Not worth the brain cycles and worry--just gonna buy a new one on Monday and the other will show up sometime. -Tim #### tHoagland ##### Rocket Builder TRF Supporter You can buy a Quark for$16 during our Holiday Sale right now, so there really isn't any reason not to have one for every rocket. They're cheaper than motor retainers... and certainly cheaper than motor cases.

There is a lot of truth in this statement. I actually ordered a Quantum and an EggFinder this week. If I don't screw up the soldering, maybe I should approach each project planning to use one of the low cost altimeters (Eggtimer or RRC2) as my default choice, unless there is a reason to use something else. As Coop mentioned above, I can see a lot of reasons to have diversity in one's collection.

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#### ksaves2

Adrian , that is whacky, but I like it.

I personally have five. An old school Missileworks RRC2 rev C that just works, two RRC2+, an RRC3, and a Mission Control that I want to fire up and use one of these days.

Planning on picking up either another rrc2+ or rrc3. May also pick up an egg timer quantum- see if I can remember how to solder.

For those who have not been around for more than 5-10 years please realize that the era we are in is fabulous for rocket avionics. The combination of capability and cost is amazing. The Missileworks and Perfectflight stuff is great, and significantly less expensive than comparable devices of the past. Eggtimer stuff looks good too if you want to build yourself. The higher end stuff like the Raven, Marsa, and Altus Metrum stuff is stuff that could not be touched 10 years ago unless you could do it yourself, or had a lot of cash.
Mission Control? I picked up a version 2 (there was a v3 I heard) and the programming worksheets are incredible. I have the documentation stashed somewhere at home. I thought a Raven was hard to understand but this thing is pretty daunting.
I believe it did it all with staging and airstarts. It's the only device I have that has a battery on the serial cable in order to connect the device to the computer. Kurt

#### OverTheTop

##### Well-Known Member
TRF Supporter
I have six Ravens and two TeleMegas. Have ordered some Egg stuff to put together to add to the collection recently.

#### Thorfire

##### Well-Known Member
Quarks for $16 - put those thinkg everywhere and donate them for the yearly raffle. Quantums for$35 - I'll have to order a few more. We must have over a dozen eggtimers, a couple perfectflite cf, a telemega, and a telemetrum. If there was a eggtimer with a gyroscope for staging and air starts (hint) we'd have at least 3 of them too. I think we need at least 2 for every av bay we're flying at any launch, plus one or two for every av bay for an active rocket without an interchangeable av bay ( nose cone bays, air start bays, etc.). I think my favorite altimeter right now is the quantum. Turn it on with the phone - no ladder required! then download the flight data while walking back after finding it

#### FredA

##### Well-Known Member
Mission Control? I picked up a version 2 (there was a v3 I heard)

I don't think V3 ever materialized.
I have a handful of the V2 units.
Definitely tricky to program - documentation was pretty sketch....

#### markkoelsch

##### Well-Known Member
Mission Control? I picked up a version 2 (there was a v3 I heard) and the programming worksheets are incredible. I have the documentation stashed somewhere at home. I thought a Raven was hard to understand but this thing is pretty daunting.
I believe it did it all with staging and airstarts. It's the only device I have that has a battery on the serial cable in order to connect the device to the computer. Kurt
In many respects, it was the most capable flight computer there was 10 years ago. Could do just about anything a Raven can.

I always wanted one and did not have the coin at the time. Traded for one last year- I will use it, but maybe not as a main line flier.

I would also not mind having an Altacc, or Olson. Quality units. Really, this is more my inner collector of stuff coming out. Prefer the new stuff. Now if the Marsa was less expensive...

#### markkoelsch

##### Well-Known Member
Mission Control? I picked up a version 2 (there was a v3 I heard)

I don't think V3 ever materialized.
I have a handful of the V2 units.
Definitely tricky to program - documentation was pretty sketch....
Fred, I believe the v3 did materialize. If memory serves, that is what I have. I agree about the programming- very capable but certainly not simple.

#### FredA

##### Well-Known Member
Ok Mark - maybe - going off memory - would have to dig out the "not currently flying" electronics box to check to see what I have.
But I know I have a handful as MissonControl's were a very capable 4-channel altimeter with great bang-for-the-buck.
But you had to know how to program them as their UI just exposed the state machine.

Can you run the nControl PC control SW on anything current?

#### Wayco

##### Desert Rat Rocketeer
Quick count on Thrustcurve, and between myself and my wife (Sharon), we have over twenty dual deploy rockets, most of which are redundant. So we could easily have forty altimeters. We fly about 10 of them a month, along with smaller stuff with motor deploy, but the dual deploy rockets all have their own altimeters. Most of the high fliers have Eggfinders. I don't move stuff around, when I'm ready to fly a rocket, I build the motor, check the batteries in the avbay, add black powder to the charge cups and pack the chute. Usually, this is all done before going to the launch. That way you can just fly rockets while the waiver is open.

#### MaxQ

##### Tripoli 2747
There is a lot of truth in this statement. I actually ordered a Quantum and an EggFinder this week. If I don't screw up the soldering, maybe I should approach each project planning to use one of the low cost altimeters (Eggtimer or RRC2) as my default choice, unless there is a reason to use something else. As Coop mentioned above, I can see a lot of reasons to have diversity in one's collection.
Just ordered a Quark.

None.

TRF Supporter

#### Lowpuller

##### Well-Known Member
I just ordered a Quark!!

#### ksaves2

Mission Control? I picked up a version 2 (there was a v3 I heard)

I don't think V3 ever materialized.
I have a handful of the V2 units.
Definitely tricky to program - documentation was pretty sketch....
You're probably right Fred. Rincon Rocketry carried it then someone else was supposed to have picked it up. I thought I saw a hobby shop in Europe was advertising a v3 but that may have been a forgotten webpage listing.
Mark, I picked up one of the last new Olsen FCP-M2's forsale and it still performs nicely. Big of course but really easy to program. I wanted something classic in my collection. I have to see where I stashed the setup program for
the Mission Control device and see if I can fire it up. Kurt

#### markkoelsch

##### Well-Known Member
I have the Mission Control software. If you need it let me know.

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
If you ask, you are not a true rocketeer.

#### fyrwrxz

##### latest photo
At least two more than you can lose in the rocket pile. Or hide from the wife. Or yourself. I recently found an old RRC2 in a bird I can't remember flying in the last two years. Still works=Bonus!

#### NateLowrie

##### Well-Known Member
In reality, you can get away with only having 2 for full redundancy launches. Here's the pro/con for that scenario:
• Pros
• Low Cost
• Cons
• You constantly need to disassemble your av-bay to move electronics between rockets (or limit yourself to a common av-bay between everything)
• If you want to fly more than one rocket with electronics at a launch you are forced to prep av-bays at the field, and prepping anything at the field sucks.
• If you lose one you need to order another one.

A good middle ground is enough altimeters to cover all the flights you do in a day. That way, you don't have to prep anything in the field and you can have common av-bays for all of the sizes you fly.

When I first started flying in 2005, electronics were expensive and could easily add up to $350 for 2 units. The cost equation was far different than now. At$16 for a quark and \$50 for a ready to go altimeter like the Stratologger there isn't a good reason not to have several available.

The one exception is the exotic flights. I fully understand why some people would only get a single telemetrum unit for all of their high altitude attempts.

#### Bat-mite

##### Rocketeer in MD
The answer to the question is: one more than he owns.