The Eggfinder Mini - A Very Small GPS Tracker

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The antenna isn't going anywhere, everything else on the board will come off before the antenna does. I would probably hold it down with a zip tie, but that and the two screws should be enough. I prefer nylon screws, but metal is OK too... just use some nylon washers to insulate the screw head and as standoffs.
Perfect, thanks.
 
Hmm, decent price.
I wish if I could borrow a tracker for my MD flight. Or maybe I could by this..
I'll have to think this over...
When will these be available??
 
Hmm, decent price.
I wish if I could borrow a tracker for my MD flight. Or maybe I could by this..
I'll have to think this over...
When will these be available??
Be aware, this is a kit you solder together.

Borrowing a tracker makes sense only if you can pay the loaner back immediately in case of CATO or other mishap, IMO.

Availability is stated earlier in this thread, maybe Aprilish.
 
Hmm, decent price.
I wish if I could borrow a tracker for my MD flight. Or maybe I could by this..
I'll have to think this over...
When will these be available??

As mentioned earlier its a kit and the complete system is the TX at $75 and a LCD reciever unit for an additional amount. Its still the cheapest unit out there at less than $150 for a complete setup.
 
As mentioned earlier its a kit and the complete system is the TX at $75 and a LCD reciever unit for an additional amount. Its still the cheapest unit out there at less than $150 for a complete setup.

OK, Thanks for the FYI!
I really appreciate it!!
Thanks,
 
I have yet to see any real reason to change from the Maestro GPS. Other than people accidentally knocking the antenna off (which can be fixed with a little RocketPoxy) it works very well for finding your rocket, which is the ultimate goal of the Eggfinder. For real-time altitude, the TRS which sends baro altitude data is much better, and I bet it works better than a uBlox too up to its limit (about 70K).

Another thing. At least with the EggFinder v1 it's a piece o' cake to use an outboard GPS.
In the case of the EF1, use the 3.3 terminals to supply the 3.3V GPS module or add some wires to the
voltage regulator on the EF2 I believe. Solder the transmit line to the second pad up from the side in this picture: IMG_20170325_232704.jpgIMG_20170325_232505.jpg

The "micro antenna" is supposed to be a Ublox chipset and the Square patch unit is a Sparkfun "nothing special" $15.95 unit. I had a Ublox unit with an amplified Sarantel Quadrifiler antenna that died and since Sarantel went out of business the amplified antennas
are no longer made of that type: https://www.csgshop.com/product.php?id_product=62
I think this type would be ideal for rocketry but alas are no longer made. Kurt
 

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Hmm, decent price.
I wish if I could borrow a tracker for my MD flight. Or maybe I could by this..
I'll have to think this over...
When will these be available??

I just shipped out a batch today. Have some more parts on the way to fill the orders that didn't ship, so I should have stock on these later in the week.
 
Here it is:View attachment 315421

I use whatever epoxy I have mixed up at the time. Grey is J&B, black is Proline 4500.

Kurt

I epoxy mine as well, but I don't recommend JB weld as it has metal in it. Not sure what that will do to the antenna. I make a small fillet around the antenna but not over the solder pads. I use 15 or 30 minute epoxy.
 
I epoxy mine as well, but I don't recommend JB weld as it has metal in it. Not sure what that will do to the antenna. I make a small fillet around the antenna but not over the solder pads. I use 15 or 30 minute epoxy.

I found some large heat shrink which also serves as strain relief for battery wires. I'm not sure if it will be as effective as epoxy but it was very easy.

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I epoxy mine as well, but I don't recommend JB weld as it has metal in it. Not sure what that will do to the antenna. I make a small fillet around the antenna but not over the solder pads. I use 15 or 30 minute epoxy.

Thanks for mentioning that Riley, I'll keep it in mind. I suspect that as long as the J&B isn't slopped on any pads or
the surface of the GPS antenna, I'm okay there. I've had several tumble recoveries with fiberglass rockets where
the EggFinders and rocket both survive a hard landing just "peachy-keen". Kurt
 
The Eggfinder Mini Assembly Guide and the build pictures are now on the Eggtimer Rocketry web site, just in time for those of you who will be getting one in the next few days. Please read the Assembly Guide thoroughly... a few of the techniques are a bit different than the standard Eggfinder TX (especially mounting the GPS module!).

I apologize ahead of time for the fuzzy nature of a few of the pictures... I didn't catch them as I was building the proto board. I'll redo them the next time I build a Mini.

Cris Erving, Eggtimer Rocketry
 
You forgot to show a fine strip of tape to cover the base slot of the GPS. Slop solder in there it's curtains for ya'. That's how I got one of my outboard GPS units. I wrecked the Maestro after I had experimented with an outboard GPS and wanted to convert
it back to stock. Once the surrounding parts were on the board, it was darn nigh impossible to solder on the Maestro and I wrecked it. Kurt
 
Done! Works like a champ too. A couple things to mention from the very amateur point of view I come to this from.

- Soldering the diode is a B****! I thought it was the hardest part of the build. The pads don't extend far beyond it's edge, and you do have to watch slopping solder in the + battery terminal hole.
- Programming the frequency is not as straight forward as with the big version. Read this part beforehand as it may change how you build slightly.
- Do yourself a favor and change to a bigger tip (with more thermal mass) for soldering the voltage regulator. The 0.5mm conical I used for everything else just couldn't deliver enough heat to do this step well.
- A magnifying glass is beyond a requirement. A strong flashlight is your friend too.
- Final weight with a JST connector is 17g.

For reference it took me 3.5 hours from opening the bag to verified working and putting a little Aeropoxy on the GPS antenna. Tomorrow it will get a possible change of frequency, and the heat shrink.
 
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Chris can you please put the Eggtimmer URL in your signature? Makes things nice and convenient.
 
Received a couple of minis day before yesterday. I was pleasantly surprised I checked my battery stash and I
had a couple of 2S, 300Mah, 7.4V packs in storage. Don't have to buy anymore. Perfect for some smaller projects I can fly
right around the corner of where I live. Will try to build one tonight. Will let you know how the
diode goes. Kurt
 
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Can you post a picture of where you put the Aeropoxy on the GPS antenna. I am not picturing it too well at this point. Thanks!
 
Can you post a picture of where you put the Aeropoxy on the GPS antenna. I am not picturing it too well at this point. Thanks!

Being clear, and a very thin coat (maybe 1 drop on each side) I will probably not be able to get an instructive picture. Kind of like ksaves2 pics in Post 57 of this thread except I didn't go to the board. I just did a thin fillet between where the brown block meets the metal it sits on. I did this on the two sides that did not have solder joints...top and bottom edges if looking at the board vertically.
 
OK. I got it. For some reason I thought you were talking about the actual antenna that bolts on and not the GPS module.
 
No, I did as was suggested in the instructions for the main antenna, and put a little red thread lock on the screw for that one.
 
Ok. I have one more question as I read through the instructions and look at the photos. When mounting the radio module, should the holes in the module be filled or do you just solder from the pad to the edge of the module. Not sure it matters, but the photos show some of the holes filled and others not filled.

Thanks!
 
Ok. I have one more question as I read through the instructions and look at the photos. When mounting the radio module, should the holes in the module be filled or do you just solder from the pad to the edge of the module. Not sure it matters, but the photos show some of the holes filled and others not filled.

Thanks!

You don't need to fill the holes, you only need the edges. If a little solder flows underneath the pad into the holes that's OK, just don't glob it all over. That's why you put the masking tape over the module... to protect all the teeny parts on the RF module from errant solder.
 
Dont forget a drop of epoxy on the batt connector where it meets the board !

Kenny
 
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