# Eggfinder Mods: First GPS

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#### kyled921

##### Rocketeer
So I got my new Eggfinder and had Connor assemble the unit. Everything looks great and I can't wait to try it out. However, I will need to add a few more things to the boards to fit my needs on the field.

- For the both the TX and RX, I plan on adding these battery connectors for a LiPo.
- For the RX, I plan on adding the HC-06 Bluetooth module by adding two pins to the board at the 3.3V and GND connections (normally LCD?). I plan on using these pins, breaking off two I guess, then soldering them on.
- For soldering, does anyone knnow if these are compatible with the RX/TX board? I know the manual says low temp and no flux? Never soldered anything like this before so I am jumping a little bit into it.
- 60W Soldering Iron
- Kester 245 Solder

Any advice on best approach/materials is welcome. I probably should have thought of all this when it was with Connor but I got distracted with side projects and figured I could learn some new skills with minimal risk on these last few items.

Thanks TRF!

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#### thomas

##### Well-Known Member
You need to connect the 3 holes 3.3V GND and RX to the bluetooth module, there is a manual for it:
https://www.eggtimerrocketry.com/attachments/File/Eggfinder_Bluetooth.pdf
You do not really need pins for it, you can directly solder wires to the holes.
Just for soldering wires to the bord its not important which soldering iron you use.
I never understand why they recommend low power soldering irons, since you need to solder longer with them an therefore supply more heat to the parts.

#### sed6

The instructions specifically call for a low watt iron with a pencil tip and special low heat solder. I built their RX, TX, LCD and the Quark with a $15 15 watt Radio Shack iron and their included low heat solder. No way would I have been successful with a 60 watt iron and some fat tip. Pony up for a new iron and do it right. I have some of their solder left over and will be happy to mail you some. #### kyled921 ##### Rocketeer The instructions specifically call for a low watt iron with a pencil tip and special low heat solder. I built their RX, TX, LCD and the Quark with a$15 15 watt Radio Shack iron and their included low heat solder. No way would I have been successful with a 60 watt iron and some fat tip. Pony up for a new iron and do it right. I have some of their solder left over and will be happy to mail you some.
Thanks for the insight. I was under the impression from the instructions that low temperature was more of a requirement than low Watt. And for tip size, does the the one I linked look to have sizes small enough? I'll swing by Radioshack on my way home today but I figured they were migrating away from a DIY electronics model to more of a phone resale outlet.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Sponsor
TRF Supporter
Soldering pencil irons are rated in watts, not temperature. Lower wattage equals less heat output so you're less likely to damage something. If you can, get a temperature regulated soldering station like a Hakko. They're somewhat more expensive, though.

#### kyled921

##### Rocketeer
Soldering pencil irons are rated in watts, not temperature. Lower wattage equals less heat output so you're less likely to damage something. If you can, get a temperature regulated soldering station like a Hakko. They're somewhat more expensive, though.
Thanks for clarifying Chris.

#### ksaves2

##### Lifetime Supporter
TRF Lifetime Supporter
I believe 15 watts or a regulated station was the recommendation. Out of my experience of building I whacked a 1st generation EggFinder tracker by dropping it. Fixed it with an aftermarket Ublox GPS receiver. Whacked another one
after I was done experimenting with an aftermarket GPS. Messed it up by trying to put the Sirf IV on it but big mistake with the other components already mounted. Dorked the GPS!. Fixed it by going back to the aftermarket GPS receiver.
Had problems with a remote switch (not Wifi) after I used it for ematch testing. I think the receiver board was whacked but
I gave up on it because #1 It was economical to start with and #2 The Wifi switch came out and #3 Then the Quantum came out. Perfect for remote ematch testing!! I whacked a Quantum as I suspect that perhaps a little solder might have
gotten under the WiFi chip and shorted two terminals. The voltage regulator chip gets hotter than heck even in the standby state. I was careful with two others by mounting the Wifi chip up with two layers of masking tape and have had
no troubles. My first Quantum was perfectly fine even though I had solder bridges galore that I corrected as each one occurred. It's worked fine. (The second one built was the one I whacked described above).
Three TRS's built that work perfectly. I keep one to practice the arming procedures on as I forget after 6 months of not flying. Four Quarks all work nicely.

I build in a glass rectangular pyrex baking dish, good lighting and magnification along with very fine angled pickups (tweezers). Tin a pad, place component, tack it down, solder the other pad and then touch up the tacked side.
Pretty standard. Kurt

#### sed6

##### Well-Known Member
Thanks for the insight. I was under the impression from the instructions that low temperature was more of a requirement than low Watt. And for tip size, does the the one I linked look to have sizes small enough? I'll swing by Radioshack on my way home today but I figured they were migrating away from a DIY electronics model to more of a phone resale outlet.
Well low watts equals low temps, I didn't look at the iron you listed cause I just saw the 60w. Since that one's adjustable and does come with the fine pencil tip it should work well, on its lowest setting. That solder you linked to looks like it needs a higher temp so it might not be ideal.

#### kyled921

##### Rocketeer
Well low watts equals low temps, I didn't look at the iron you listed cause I just saw the 60w. Since that one's adjustable and does come with the fine pencil tip it should work well, on its lowest setting. That solder you linked to looks like it needs a higher temp so it might not be ideal.
That was part of my confusion when looking at irons. The 15 watt I picked up from Radioshack yesterday list the operating temp closer to 300°C, yet the 60W I linked says it does 200-450 °C. This is why I hate electronics

I guess my takeaway from this is that I should have forked over the extra cash for the LCD RX and I would have had BT connections right from the get go. Oh well, learn and live. And at least I'll have the supplies for next time Egg-product I buy

#### Steve Shannon

##### Well-Known Member
TRF Supporter
Low watts does not necessarily equal low temps, but it does mean that it can't produce heat as quickly; it can't heat up as quickly or recover as fast. With a cheap, non-temperature controlled pencil you may have a tip that's too hot, but once you begin soldering can't keep up.
I used to assemble prototype SMT PCBs. I like a temperature controlled pencil with interchangeable tips. Currently I use a nice Weller with a tiny flattened tip, but I've seen and heard good reports on the Haako.

#### ksaves2

##### Lifetime Supporter
TRF Lifetime Supporter
That was part of my confusion when looking at irons. The 15 watt I picked up from Radioshack yesterday list the operating temp closer to 300°C, yet the 60W I linked says it does 200-450 °C. This is why I hate electronics

I guess my takeaway from this is that I should have forked over the extra cash for the LCD RX and I would have had BT connections right from the get go. Oh well, learn and live. And at least I'll have the supplies for next time Egg-product I buy
The 1st generation receiver is good for ground static testing with no beep....beep....beep. The beeping is helpful with actual rocket tracking. All is not lost. Kurt

#### kyled921

##### Rocketeer
Well pending my budget for recovering from a CATO Saturday (see Propulsion thread) I found a creative solution to possibly mount my Eggfinder in the nose cone. It turns out, prescription bottles are the exact length of the TX board, and with a hole drilled in the bottom can fit the antenna! The lid also locks in place and keeps everything securely in place. Also makes it easy to swap between rockets! Going to try a few configurations out. Still need the batteries and will need a wood sled piece to attach everything as a unit inside, but should work pretty well. And they're free! Will post pics if I get something worked out.

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#### amarillo_rocket

##### Well-Known Member
If all you plan to do is an occational soldering project a 15-25 watt Radio Shack iron is all you need. If in the future you plan to do more soldering projects I would highly recommend a Hakko. The model I use is a FX-888D. After replacing several of the less expensive Radio Shack and Weller irons over the years I decided to try the Hakko. Best soldering investment I have made. Heats up in 30 seconds, fully adjustable temp with digital readout, many different tip options for all needs from fine point to large heat delivering tips. It a great tool and a real time saver. I also use a Hakko desoldering tool. Expensive but worth every penny if you do a lot of projects. I like Hakko also because there are replacement parts like heating elements.

#### BLKKROW

##### Sponsor
TRF Sponsor
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If you are using the LCD you may want to look into my 3D printed enclosure to make recovery super simple. You can even upgrade to a belt clip/lanyard hook.

#### KenRico

##### 'Just the Tip'
If all you plan to do is an occational soldering project a 15-25 watt Radio Shack iron is all you need. If in the future you plan to do more soldering projects I would highly recommend a Hakko. The model I use is a FX-888D. After replacing several of the less expensive Radio Shack and Weller irons over the years I decided to try the Hakko. Best soldering investment I have made. Heats up in 30 seconds, fully adjustable temp with digital readout, many different tip options for all needs from fine point to large heat delivering tips. It a great tool and a real time saver. I also use a Hakko desoldering tool. Expensive but worth every penny if you do a lot of projects. I like Hakko also because there are replacement parts like heating elements.
+1

I bought the Hakko on sale from Frys and use it often.

Amarillo what tip do you like for the eGG stuff?

Kenny

#### martinjaymckee

##### Well-Known Member
I've used my Hakko on all my Eggtimer devices -- I use a 2.5mm chisel tip almost exclusively. There are a few times that a smaller tip would be nicer ( and I do have them, just in case ), but the advantages of a larger tip are many. It's easy to do drag soldering on high pin-count, small-pitch packages, and larger tips transfer the heat more quickly, so you don't have to wait as long at each joint.

One of the most important things, regardless of the tip shape, is to keep it clean ( with a wet sponge, or brass wool ). As long as the tip is bright and shiny, you're in a much better position to actually get clean joints -- with or without additional flux.

Martin Jay McKee