Smallest rocket recommendation for an on-board altimeter...

Hello, I'm currently in "low power" territory (i,e, "B" and "C" engines), but I would still like to try out an on-board altimeter. I see some extremely small models on the market (North Coast Rocketry's Adrel, PerfectFlite's FireFly, etc. - the Estes one seems a little too bulky for smaller rockets) - are these small and light enough for even "B" engine flights? It sounds like they can attach to the nose cone. Just curious about the recommended bottom threshold for these. Thanks!

https://northcoastrocketry.com/products/adrel-atl-bmp-altimeter can definitely fit in teeny tiny : 8mm x 19mm @ 0.6g

I put the Firefly in many small LPR rockets. Just designed and 3D printed a “sled” to hold it in place in the Quest Payloader One payload tube a few days ago. I’m looking forward to launches nag at next Saturday’s club launch.

I've put Altimeter 2/3 (similar size as Estes) in Alphas and a Crossfire. Probably affects the altitude some, but no hard numbers for obvious reasons. Smaller ones like the Adrel and Firefly would be better, performance-wise.

Altus Metrum MicroPeak (1.9g inc battery)

https://altusmetrum.org/MicroPeak/

spigalau said:

Altus Metrum MicroPeak (1.9g inc battery)

https://altusmetrum.org/MicroPeak/

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Awesome. I had not seen that one. I'll look into that as well. Thank you!

Flightsketch Mini: bluetooth data download to iPhone, $18!!!

Whenever the Jolly Logic Altimeter 4 comes out, that'll be a good candidate as well.

neil_w said:

Flightsketch Mini: bluetooth data download to iPhone, $18!!!
.

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Been out of stock for ages.

5x7 said:

Been out of stock for ages.

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Well, they're just getting started. There will be more.

But yeah, if you want one *now*, that's not your best option.

ewomack said:

Hello, I'm currently in "low power" territory (i,e, "B" and "C" engines), but I would still like to try out an on-board altimeter. I see some extremely small models on the market (North Coast Rocketry's Adrel, PerfectFlite's FireFly, etc. - the Estes one seems a little too bulky for smaller rockets) - are these small and light enough for even "B" engine flights? It sounds like they can attach to the nose cone. Just curious about the recommended bottom threshold for these. Thanks!

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How small would you like to go? One of the 2019-2020 contest year events in the NAR’s National Rocketry Competition is 1/2A altitude with altimeter. We had a little pickup contest today - the day after NARAM-61 was over and therefore the first day of the new contest year - and flew a number of 1/2A altitude flights. I flew the model in the first picture (built several years ago) with an Adrel ALT-BMP (shown next to it) to over 170 meters. (this was a piston-launched flight)

Since the MicroPeak and the FireFly won’t fit in BT-5, the models carrying them (both were used today for this event) didn’t go as high. See the three altimeters compared in the second picture.

I routinely fly a FireFly, wrapped in a little fleece pouch my wife made for them, stuffed in the nose cone of an Alpha III or Alpha VI on motors down to A.

Avoid the Estes altimeter. It’s heavy and it’s VERY fussy about getting a reading. If you must have something that can be hung from the nose cone without taking much of a precaution to protect it, the Jolly Logic devices (AltimeterOne, Two and Three) are all good choices. In something as small as an Alpha it’s a challenge to get a device that big in and still have room for a parachute, but it can be done. On longer models it’s no problem.

I wish Russ Parrish would decide what to do about the Flight Sketch Mini. It clearly doesn’t make economic sense to sell it for $18 but since it’s narrower than a FireFly it will fit in a BT-20 coupler which opens up applications where the FireFly won’t work and provides an alternative to MicroPeak and Adrel ALT-BMP.

BEC said:

I wish Russ Parrish would decide what to do about the Flight Sketch Mini. It clearly doesn’t make economic sense to sell it for $18

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The $18 price never made sense to me. Double that and it's *still* a good deal.

I have long felt that Estes is making a mistake by not getting more seriously into flight electronics, particularly altimeters, cameras and shrouds, etc. I think it would be very appealing to the retail buyer.

The PerfectFlite Firefly is small enough to fit in BT-20 rockets and the price is pretty good. I bought a few recently to replace the one I can no longer find. Only weighs a few grams, so flying it on a B is no problem.

The airframe I'm building is .98" in diameter, so the FireFly's .68" width may be tight, but it sounds like it still might work. I ordered one (as others have said, it has a nice price), but I don't know if it will arrive in time for the next launch. Yet there's always the launch after that...

The FlightSketch Mini has been a classic example of "you don't know what you don't know..." We've learned a lot over the last couple of months and the good news is it's getting better. There is another round of boards out for fab now. The new version does have an LED for status indication and *should* meet requirements for NAR approval.

The Mini has flown down to an 18mm model on 1/2A motors.

There will be a little price bump at the re-release to cover the new assembly costs. It is very inexpensive, that was the goal. For what it's worth, the BoM cost for the hardware is ~$8.60 before assembly.

We'll post a release date when we know more. There are a couple of other projects we're working too.

Thanks,
Russ

The Estes altimeter should be avoided at all costs. Mine never worked and then the battery died. The batteries are hard to find. Besides, tons of great altimeters out there, so no need to go third class with the Estes one. I love Estes motors and they make great kits, but the altimeter was not on of their better products.

ewomack said:

The airframe I'm building is .98" in diameter, so the FireFly's .68" width may be tight, but it sounds like it still might work. I ordered one (as others have said, it has a nice price), but I don't know if it will arrive in time for the next launch. Yet there's always the launch after that...

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As I said, I fly FireFlys in Alphas which are BT-50 the size you are using. I have flown one a bunch in a regular Alpha (so can’t use the tuck-it-into-the-nose-cone trick I can use on anything that uses the Alpha III nose cone). I use the little fleece pouches my wife made to protect the unit in this case. Same with either FlightSketch Mini or MicroPeak. I’ve never flown an Adrel in anything but a dedicated payload compartment.

gtg738w said:

The FlightSketch Mini has been a classic example of "you don't know what you don't know..." We've learned a lot over the last couple of months and the good news is it's getting better. There is another round of boards out for fab now. The new version does have an LED for status indication and *should* meet requirements for NAR approval.

The Mini has flown down to an 18mm model on 1/2A motors.

There will be a little price bump at the re-release to cover the new assembly costs. It is very inexpensive, that was the goal. For what it's worth, the BoM cost for the hardware is ~$8.60 before assembly.

We'll post a release date when we know more. There are a couple of other projects we're working too.

Thanks,
Russ

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Thanks for popping in and bringing us up to date. I’ll be looking forward to the new revision after I get home from my NARAM and visiting trip. Still in Muncie at the moment.

I flew a rocket with a .98" diameter and a B engine with the FireFly altimeter attached to the nose cone today. Clear plastic wire called "Supplemax" lashed it to the nosecone hook. It survived the flight intact, but the FireFly directions clearly state to tie it to the nosecone only "as a last resort, if accuracy isn't of paramount importance." So who knows what the results mean? Since I didn't have a Field Data Display and I didn't have time to watch the altimeter light blink during recovery on the field, I had to turn the altimeter off to preserve the battery. So I only have the altitude from the last flight, which blinks out "503" or five blinks, ten blinks, and three blinks. It certainly looked like it went higher than that, but I don't have a lot of experience with judging height from the ground yet. It climbed to a point where it was difficult to see, but I did see the parachute eject, so perhaps 503 feet is somewhat accurate?

In any case, the altimeter survived the flight and returned data, but the instructions say that the method I used may not return accurate data. It was a nice flight regardless.

Do you have any vent holes in the body of the model?

That looks like the nose cone used in the current Alpha kits. An Alpha on a B is typically 550-ish feet so you’re certainly in the ball park with 503 depending on the details of the model.

I put FireFlys in a little fleece pouch my wife made when flying them like this.

BEC said:

Do you have any vent holes in the body of the model?

That looks like the nose cone used in the current Alpha kits. An Alpha on a B is typically 550-ish feet so you’re certainly in the ball park with 503 depending on the details of the model.

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No, no vent holes.

The kit is actually an Estes Black Brant III, flown with a B6-4 engine.

neil_w said:

The $18 price never made sense to me. Double that and it's *still* a good deal.

I have long felt that Estes is making a mistake by not getting more seriously into flight electronics, particularly altimeters, cameras and shrouds, etc. I think it would be very appealing to the retail buyer.

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I wonder if there is some way they can redesign the plastic nosecones to accept one of their altimeters, or devise some sort of module you could firmly attach to the bottom of the nosecone? I'd be interested in how high my models are going, but don't want to go through a lot of experimentation and hassle to jury rig something.

I was thinking the same thing. It would be great if Estes had a few different special nose cones that had a slot to hold the altimeter. It could even be done so it's on the visible part of the nose cone perhaps with a clear shield over it.

Bill S said:

I wonder if there is some way they can redesign the plastic nosecones to accept one of their altimeters, or devise some sort of module you could firmly attach to the bottom of the nosecone? I'd be interested in how high my models are going, but don't want to go through a lot of experimentation and hassle to jury rig something.

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Well, you already can just hang an altimeter from your nose cone, or where the parachute attachment is, in a protective pouch if necessary. If it's in a sealed compartment you won't get good tracking on the way up, but you should get a good reading at deployment and on the way down.

But I also agree that Estes could/should take advantage of their vertical integration and retail footprint to push the electronics a bit more. That said, I am sure they have a mile-long to-do list, and they have to prioritize.

As a lot of people have already pointed out, the Firefly will fit comfortably in a 18mm body tube. I was able to get into a BT20 coupler but it's a very tight fit; I had to wiggle it into place and extracting it was difficult. It slides in and out of the bodytube easily. Here's a picture of my Firefly with a Estes Viking (BT20)

gtg738w said:

The FlightSketch Mini has been a classic example of "you don't know what you don't know..." We've learned a lot over the last couple of months and the good news is it's getting better. There is another round of boards out for fab now. The new version does have an LED for status indication and *should* meet requirements for NAR approval.

The Mini has flown down to an 18mm model on 1/2A motors.

There will be a little price bump at the re-release to cover the new assembly costs. It is very inexpensive, that was the goal. For what it's worth, the BoM cost for the hardware is ~$8.60 before assembly.

We'll post a release date when we know more. There are a couple of other projects we're working too.

Thanks,
Russ

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So excited for this! Will the next version will be compatible with Android phones? Looking forward to more interesting stuff from FlightSketch...

Scott_650 said:

So excited for this! Will the next version will be compatible with Android phones? Looking forward to more interesting stuff from FlightSketch...

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Yes, the hardware is universal. Everything will be Android compatible as soon as the app is released.

Let us know what you'd like to see - votes help priority!