PerfectFlite Firefly?

So last night I was reading the latest issue of Sport Rocketry Magazine and saw an ad for the Perfectflite Firefly. It is a new mini altimeter that reports apogee and maybe data logs as well. But I really don't know. Because, when I check their website or Google it, I get nothing. Anyone know more about it? It looks interesting at the price they listed ($40 or $45, Don't recall).

I noticed that, too. Great issue, BTW. Lots of excellent pictures.

The ad reads "less than $25!" Also reports max-velocity.

Does appear that the issue went to print before they got their web site updated, or perhaps there has been a delay in manufacturing. You could call them, but then they say "Net an online discount at: PerfectFliteDirect.com", and of course, there's nothing there.

I suspect it is not a dual deployment device.

Correct. Just peak altitude and speed.

Gee, that sounds intriguing. I tend to collect altimeters, it seems.

My copy of that issue of SR hasn't arrived yet.....

Does it have accelerometers? Does it say anything about the max G forces?

Says it will fit in an 18mm (BT-20) tube. Nice for recording altitude and speed for small rockets.

Got the magazine today. If the illustration in the ad truly is "actual size" then it's pretty tiny, but about half again larger and about twice the mass of the Altus Metrum MicroPeak, but at half the price. I figure "less than $25" means $24.99.

It looks like it uses a small lithium coin cell for power (the end of the holder is sticking out from the back of the board in the picture in the ad). And I'd guess it reports out with flashes rather than beeps (like the MicroPeak, the Adrels, and the now-discontinued Winged Shadow devices).

I am wondering what "Optional field data display provides additional flight information" means. I doubt it's a full-up recording altimeter like the MicroPeak....but I am really interested to find out. And at that price (and size) it'll be great for working with kids and science projects I expect.

As I say, I tend to collect altimeters.....

I went home last night and saw the ad again. I was wrong initially on price, it is "under $25". It appears to be the width of the P-nut but only slightly longer than it is wide. It also doesn't appear to data log, just report peak speed/altitude. But at under 4 grams and for $25, this is pretty amazing. You could fit this in an Estes Viking.

Now they just need to get the thing NAR contest certified, oh and actually start selling them!

Another option is the MicroPeak from Altus Metrum (though also currently out of stock).

MicroPeak is contest certified and barely larger than a watch battery. We flew one in the nosecone of an Alpha III at SLI.

The cool thing is it provides data download, so you get more than just altitude from it.

-Kevin

troj said:

Another option is the MicroPeak from Altus Metrum (though also currently out of stock).

Click to expand...

We've got plenty of MicroPeaks available, and I've got enough parts to make another huge pile sitting here.

I see it on their webstore now! https://www.perfectflite.com/Firefly.html https://www.perfectflitedirect.com/firefly-altimeter/
I've been wanting a small, light, inexpensive altimeter that I can just stick in a rocket to measure peak altitude ans speed. Kinda like a simplified version of the Altimeter 2. cheaper, and fewer data points. Just max velocity and altitude. Methinks I'll be buying one of these very soon. Between the price, size and feature set, it looks like a winner!

Nate

Love that price point!

Greg

Thanks for the heads up. I'll order a couple and give 'em a try.

Nothing about the "optional field data display" yet, though.

Ordered one- looks like I mighta got the last one?? wouldn't go through when I added 2 to cart.
edit: yup, now showing out of stock- sorry to anyone who was gonna grab one:blush:
Nate

Must have gone quickly.

I ordered two. They arrived today.

Here's a picture of one sitting next to the ad in Sport Rocketry. Yup, actual size. This one actually measures 0.2g lighter than claimed. A very pleasant surprise.

It just fits in a BT-20.

Weather around here is supposed to be not windy and rainy on Saturday....so I might be able to nip out and give it a try.

I flew one of them three times this afternoon. It works as advertised - with good plausible and consistent results on a model I've flown with lots of altimeters and so know what to expect.

If weather allows tomorrow I'll have more time and can do some multi-altimeter flights to see how well it matches others on the same flight.

But the first impression is a very good one.

Mine should be here tomorrow- getting excited! What are people's plans for integrating these into LPR or MPR rockets that don't have a real payload bay built into them?

Nate

Mine arrived today in great shape with a very nice instruction manual, the unit looks sweet! And small!!!

I was contemplating How I would fit this into most of my rockets, and I came up with this:

A couple inches of BT 20...

A piece of pine with a circular groove cut in it 18mm in diameter (courtesy of a Forstner bit) cut to a roughly round shape, sanded down (with a belt sander) so the OD is just slightly larger than 18mm (maybe 20 or 22).
wood glue in the channel, attach the BT 20, and then insert your favorite variety of packing foam. (I used some pipe insulation I had leftover from a stand I made that I then cut into squares.)
Seal it with some hot glue, drill some vent holes and viola!



Now you can put the altimeter in, cushion the other end with a bit more foam and stick it in just about any NC larger than BT 20.

I used an Estes D region tomahawk as my first guinea pig:


A hole in the nose cone courtesy of the same drill bit used earlier,



In we go, and a couple dabs of hot glue should keep it in and seal it well enough to keep any unwanted gasses out (it'll be on top of wadding/nomex, a parachute, shock cord etc. after all)

Now just some sampling holes in the NC (preferably in or near the shoulder) ind it's ready to fly!

Nate

I now have four flights on each of two FireFlys and have done some static testing using the little bottle/syringe arrangement that Adept sells for such things. The news is all good. I'm seeing very good agreement between the FireFly and PerfectFlight APRA, Altus Metrum MicroPeak and a beta AltimeterThree. And the two FireFlys in static tests agree with each other exactly. (I've not yet flown them both together on the same flight.)

The little green LED that blinks out the result is kind of hard to see in the sunshine, but that's the only complaint (and it's a minor one) I have so far.

And....it appears they're back in stock on perfectflitedirect.com.

No connection with PerfectFlite - I just like the product.

How did mount yours? Any photos?

All flights were inside a payload section - the models were a BMS School Rocket with the optional payload section, a modified Estes Eliminator with the upper four inches converted to a payload section via a coupler and a ply disk, my very tired Estes Nova Payloader (the flight yesterday was its 69th), and a Semroc Mini Aero Dart, which also has a standard payload section.

For such tiny altimeters I generally wrap them loosely in either wadding or thin sheet foam so that the pressure sensor can still "feel" the pressure change within the payload section then just drop it in. The main objective is to keep it from rattling around in there too much at ejection when things get shaken up rather dramatically. Since the dual-altimeter flights were alongside/above the beta Altimeter/Three, the amount of soft padding was pretty small. Then I put a bit of Scotch Multi-Task tape across the nose cone/payload section joint for insurance.

All of these models have three or four small static ports in the payload sections.

I flew mine on Saturday in a couple rockets with good data on all flights.

First was the Mini Comanche 3 flying on a single A3T. Altitude of 250ft and velocity of 71 mph. Sounds reasonable. The payload bay separated at apogee and freefell, but everything was fine inside. This was mounted in a purpose cut payload section with 4 vent holes.

Net up was the Estes Guardian on a D13W. 1109ft, and 248mph. Both sound pretty accurate. This was resting in the upper tube above the transition and below the NC. 3 vent holes.
My DD Argent on an H210R came out at 2219ft from the RRC2+, and 2222 from the firefly. That's a difference of .1%! 357 mph. This was in my little capsule hot glued on top of the transition with 4 vent holes.

Last flight with this on-board was an estes Astron Elliptic 2 flying again on a single A3T. it recorded 248 ft and 62 mph. This is interesting, because it looked faster than the Comanche flight. I'm assuming its just because it was at a bit more of an angle coming off the rod. It was in a purpose built payload section with 4 vent holes.

All the vent holes were sized according to the formula in the instruction manual. some were bigger, because I didn't have a small enough drill bit.

So, I have nothing but good things to say about this altimeter. It recorded well, even in the high breeze. I was certain that it was going to falsely detect launch in the few minutes between when it was turned on, and when it was launched while the wind blew through it at every angle. I was very pleasantly surprised! It fit snugly in the BT 20, and was easily mounted on top of the transition in the Argent. Tiny unit, great price, accurate data. I like it.

Nate