Eggfinder Bay Examples

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Wayco said:
I have two Eggfinders, the first one was installed in the N/C of my 5" Jart:

Plenty of room in a 5" rocket, so there were no metal parts within 2" of the antenna:

I built a handheld case that holds my RX with a 6 dbi antenna, a HC-06 Bluetooth module and a 9v battery that is pictured in the above shot.
The second one was installed in the N/C of my MD Blackhawk 54:

With both installs, I made the N/C bulkhead/retention using a kevlar Y harness looped around a hardwood dowel that was mounted in the N/C coupler. The only metal near the antenna is three 6-32 screws and pem nuts that hold the coupler into the N/C.

The space was so limited that the antenna sticks several inches into the payload tube.

I also adapted the original Eggfinder into my 3" Dark star and my 4" Dark star Extreme:

It fits easily into the N/C and the antenna is inside the coupler:

The sled is held in place by a zip tie that goes through holes in the hardwood dowel and around the antenna:

I have four Eggfinder flights in the 5" Jart, from 4600 ft. to 10,126 ft. All held lock throughout the flight and were recovered using the handheld RX linked to an Android phone using the "Rocket Locator" app.
I have one flight in my 3" Dark star on an AT K513 Fast Jack that lost lock but got it back before apogee. Same easy recovery.
The Blackhawk 54 and 4" Dark star have not been flown yet. Ground testing indicates that the smaller the N/C, the less range I get. Flight testing will resume at Airfest over the last weekend of August. Planned flights include the Blackhawk test flight on a J460 to 6700 ft., the 5" Jart on an L1115 to 12,000 ft. and my L-3 attempt with the Dark star Extreme on an M1297 to 11,000 ft.
If the first flight on the Blackhawk goes good, and conditions permit, I have a CTI L935 that could test the range of the Eggfinder to over 17,000 ft.
Click to expand...

Nice setups. Would you happen to have a web link for the antenna's (part number and price) used in your RX and TX units by any chance?

-John
 
Tetrahedron said:
Nice setups. Would you happen to have a web link for the antenna's (part number and price) used in your RX and TX units by any chance?

-John
Click to expand...

Perhaps Wayco will reply to clarify but I believe it is something like this:

https://www.ebay.com/itm/900MHz-3-5...osters_Extenders_Antennas&hash=item439af1ce9d

If one wants to track from a stationary spot say from a vehicle, this might give a bit more gain:

https://www.ebay.com/itm/Cellular-c...ectional_Network_Antennas&hash=item5afcd4544a

The magnet isn't worth squat in the base so it isn't worthwhile for driving. Another thing, I'd take the Chinese quoted specs with a grain of salt. The longer receive antenna will have a bit more advantage to a point. I'd believe the range quotes that folks are posting here and they say more higher altitude flights are in the works for the Egg Finder. If there is someone who could track with the Xastir program, all the received packets could be saved for later review in an easy to read format. MapSphere can save the packets but it's in a cryptic file format. Readable but cryptic.
Nonetheless, to simply find a rocket, one don't hafta' save nuth'in.:surprised: Just enter coordinates by hand or make the EF receiver portable with B/T to carry out to the recovery site. (The LCD version of course has more utility. The stock EF receiver can be made battery portable with B/T to pair with an Android device. The LCD is a nice backup though) Kurt
 
The first link that Kurt posted up is a similar antenna, but not exactly what I have. Juan posted up a link in the original thread for the 5 dbi antenna, but once again, it's out of stock:
https://www.ebay.com/itm/5DBi-Wirel...NQEpkSl8IKX0koxBut5tU%3D&orig_cvip=true&rt=nc
Kurt is correct about the advertised gain being a bit optimistic with some of these antennas, but I'm getting good range with the ones I have. I haven't used the magnetic based antenna yet, but plan to at Airfest next month.
 
Linx makes a similar one, but it's going to cost you a bit more, p/n ANT-916-CW-HWR-RPS , they run around $10 each from Mouser, Digikey, etc. They claim 1.9 dB at 916 MHz, that's probably more realistic than some of the other antennas that I see. They have hundreds in stock, so you're not gonna have any trouble getting one.
 
Here is my AV bay Eggfinder/Eggtimer hardware in my 38mm min dia rocket, took some doing to get it all crammed in there. :bangpan:

The timer is powered by a magnetic switch, I will have to turn on the Finder before I load it up which is all well and good being that you need to make sure it has picked up the satellites before you go out to the pad any way.


Here are the lipos I used, you cant really see them because they are all covered up with wires. The nine volt is just for size comparison.

TA

20140726_172751.jpg

20140726_172637.jpg

20140726_172629.jpg
 
thobin said:
Here is my AV bay Eggfinder/Eggtimer hardware in my 38mm min dia rocket, took some doing to get it all crammed in there. :bangpan:

The timer is powered by a magnetic switch, I will have to turn on the Finder before I load it up which is all well and good being that you need to make sure it has picked up the satellites before you go out to the pad any way.


Here are the lipos I used, you cant really see them because they are all covered up with wires. The nine volt is just for size comparison.

TA
Click to expand...

Nice. You going to use a cable cutter for main deployment like the Archetype rocketry unit?

https://lkal32.blogspot.com/p/cable-cutter.html

Kurt
 
Here's a couple of designs that I came up with.

First one is design experiment with a 4" plastic nosecone. I used a 29mm motor tube and an Estes motor retainer. This sled will use a 9V battery that will set in front of the bulkhead, held in place by the two blocks on the sled. There is little room for the battery to move around in the 29mm tube, so the blocks fore and aft, and maybe a cable tie around the middle is all that will be necessary. The Tx board will sit on the top, antenna pointed up.

2014-09-14 18.06.44.jpg2014-09-14 18.07.12.jpg

Second setup is in a3" fiberglass wound nose cone on a Darkstar 3. The build was originally done "glueless" as shown in CJ's epic build thread, but I concluded that the glueless setup was (for me, anyway) a problem looking for a solution. We had tested the Eggfinder range and saw a material degradation in range when the antenna was next to the rod. (More on that in a different thread). So I cemented the coupler to the NC, ditched the rod, cut a hole in the bulkhead and make a hatch to fit over it, added the hardware, and then cemented the bulkhead inside the coupler, "old school" style.

2014-09-14 18.03.14.jpg2014-09-14 18.03.35.jpg2014-09-14 18.05.41.jpg

The sled for this setup was built for a 7.4V lipo battery held in with one cable tie fore/aft, and two more around the battery and sled. It has flown on a J motor successfully, but for the bigger motors we are planning to use in this rocket I am going to add another block forward of the battery to prevent any fore/aft movement, with cable ties around the middle just to hold the battery in position between the blocks.

For future builds, I believe I'll use the Estes retainer method where it will fit the nosecone. A standard sled that moves between rockets seems like the way to go. I will probably use G10 for the sled and retainer bulkhead for a bit of added strength. The 29mm retainer/motor tube will fit in the 3" nosecone with the recovery hardware offset as shown here. It would probably also work with at 54mm nosecone if you used a kevlar recovery attachment instead of hardware.
 
Last edited:
...I've been struggling for a bit now with a good way to swap between sleds wile buried in a nosecone. Using an screw retainer is pretty brilliant and I'll have to look into it.
 
I'll add a description of one other bay that I am working on. I'm part-way through building it, so I don't have anything worth taking photos of unless you all want to see a messy bench-top.

I started out wanting to build a freestanding bay that could be moved between rockets. I ended up with the design above that put the bay in the NC and moved the sled around instead, but that still would let me use a separate freestanding bay so I am working on it. It will consist of a 29mm motor tube with a fixed bulkhead at one end. That bulkhead will hold an attachment point, so I will fiberglass the bulkhead to the tube. And while I'm at it, I will put a single wrap of glass on the motor tube to add a bit of extra impact resistance. The other end of the tube will be finished with the same Estes 29mm retainer that is in the picture above, so the sled can be used in rockets where I didn't build a bay into the NC.

Only problem with this approach is that the tube can be quite long, depending on the antenna used, and the motor retainers add some additional length and girth. So this won't fit in smaller rockets. With the wire antenna, it is going to be nearly 7" long. But since it is designed to hang in free space, the wire antenna will be in it's optimal position. If I were to run this in my Darkstar Junior (54mm body tube), I might be able to get it into the drogue section if I didn't go crazy with the length of the shock cord. But I doubt there would be enough room for it in the payload section when the main and recovery gear is packed. Thinks get much easier with bigger and fatter rockets.
 
Dad Man Walking said:
Here's a couple of designs that I came up with.

First one is design experiment with a 4" plastic nosecone. I used a 29mm motor tube and an Estes motor retainer. This sled will use a 9V battery that will set in front of the bulkhead, held in place by the two blocks on the sled. There is little room for the battery to move around in the 29mm tube, so the blocks fore and aft, and maybe a cable tie around the middle is all that will be necessary. The Tx board will sit on the top, antenna pointed up.

View attachment 184719View attachment 184720

Second setup is in a3" fiberglass wound nose cone on a Darkstar 3. The build was originally done "glueless" as shown in CJ's epic build thread, but I concluded that the glueless setup was (for me, anyway) a problem looking for a solution. We had tested the Eggfinder range and saw a material degradation in range when the antenna was next to the rod. (More on that in a different thread). So I cemented the coupler to the NC, ditched the rod, cut a hole in the bulkhead and make a hatch to fit over it, added the hardware, and then cemented the bulkhead inside the coupler, "old school" style.

View attachment 184721View attachment 184722View attachment 184723

The sled for this setup was built for a 7.4V lipo battery held in with one cable tie fore/aft, and two more around the battery and sled. It has flown on a J motor successfully, but for the bigger motors we are planning to use in this rocket I am going to add another block forward of the battery to prevent any fore/aft movement, with cable ties around the middle just to hold the battery in position between the blocks.

For future builds, I believe I'll use the Estes retainer method where it will fit the nosecone. A standard sled that moves between rockets seems like the way to go. I will probably use G10 for the sled and retainer bulkhead for a bit of added strength. The 29mm retainer/motor tube will fit in the 3" nosecone with the recovery hardware offset as shown here. It would probably also work with at 54mm nosecone if you used a kevlar recovery attachment instead of hardware.
Click to expand...

That's an absolutely excellent method I'm going to copy on a couple of 3" mules I'm going to use for Ex loads. For bulkheads, I suggest as thick as one can tolerate as it will give as much surface area for
the epoxy to catch on the inside of the coupler/nosecone. A possible option would be to use some finishing screws through the coupler into the bulkhead for strength while the epoxy is still setting up. Drill pilot holes fast and then turn the screws in. I wouldn't do it after the epoxy has set as I'd be afraid the bulkhead/nosecone or coupler interface might crack free from the pilot drill vibration. If the bulkhead is secured well and "cannon overloads" aren't used for main deployment, might not need to secure with screws. On three nosecone/tracker projects I've used .6 to .75" thick bulkheads with a centrally located
hole for the tracker to go through with blindnuts and another bulkhead for the eyebolt and 6 hex screws to hold the cover to the bulkhead. Kurt
 
How much metal in a Bay would cause issues with range and lock? Such as would a 6 inch 1/4" aluminum tube that has a nut on it interfere with the Eggfinder?
 
If it's close to the antenna, yes, if it's on the other side of the AV bay, no. Aluminum isn't quite as bad as steel, but it will still attenuate the signal... how much, that's hard to say. Ground test it with and without the tube, and if you don't see any discernible difference then you're probably OK to fly it.
 
Im trying to incorporate on/off switches into my TRS system. I flew it yesterday and I just connected the battery's right before the flight. Being inside the nosecone it was a pain to do this at the pad. I would like to used one switch for both the deployment side and the tracker side. Is this possible? I don't want to use the remote switch because it's already very crowded enough in the NC and I don't want to mess with additional electronics. Is a single switch possible? If anyone has any pics of their setups please post em.
 
bill2654 said:
Im trying to incorporate on/off switches into my TRS system. I flew it yesterday and I just connected the battery's right before the flight. Being inside the nosecone it was a pain to do this at the pad. I would like to used one switch for both the deployment side and the tracker side. Is this possible? I don't want to use the remote switch because it's already very crowded enough in the NC and I don't want to mess with additional electronics. Is a single switch possible? If anyone has any pics of their setups please post em.
Click to expand...

Bill, On a 38mm rocket that I'm using an archtype cutter for main deployment, I am using a 1200Mah 2S battery to power the device and for the deployment charges. I have one of the Featherweight screw switches I use to "enable" the pyro side of the wiring harness accessible through the static port. I too, plug in the battery to activate the TRS and then screw "on" the pyro power when on the pad. I can't see away around not having two switches. On a larger project, one could consider a double pole single throw switch to activate both circuits at one time. My setup is like thobin's pictured in #35 except I just have the TRS, the battery, switch and antenna. The antenna goes into the nosecone that I cut an opening in the shoulder for. Kurt
 
Dad Man Walking said:
Here's a couple of designs that I came up with.

First one is design experiment with a 4" plastic nosecone. I used a 29mm motor tube and an Estes motor retainer. This sled will use a 9V battery that will set in front of the bulkhead, held in place by the two blocks on the sled. There is little room for the battery to move around in the 29mm tube, so the blocks fore and aft, and maybe a cable tie around the middle is all that will be necessary. The Tx board will sit on the top, antenna pointed up.

View attachment 184719View attachment 184720

Second setup is in a3" fiberglass wound nose cone on a Darkstar 3. The build was originally done "glueless" as shown in CJ's epic build thread, but I concluded that the glueless setup was (for me, anyway) a problem looking for a solution. We had tested the Eggfinder range and saw a material degradation in range when the antenna was next to the rod. (More on that in a different thread). So I cemented the coupler to the NC, ditched the rod, cut a hole in the bulkhead and make a hatch to fit over it, added the hardware, and then cemented the bulkhead inside the coupler, "old school" style.

View attachment 184721View attachment 184722View attachment 184723

The sled for this setup was built for a 7.4V lipo battery held in with one cable tie fore/aft, and two more around the battery and sled. It has flown on a J motor successfully, but for the bigger motors we are planning to use in this rocket I am going to add another block forward of the battery to prevent any fore/aft movement, with cable ties around the middle just to hold the battery in position between the blocks.

For future builds, I believe I'll use the Estes retainer method where it will fit the nosecone. A standard sled that moves between rockets seems like the way to go. I will probably use G10 for the sled and retainer bulkhead for a bit of added strength. The 29mm retainer/motor tube will fit in the 3" nosecone with the recovery hardware offset as shown here. It would probably also work with at 54mm nosecone if you used a kevlar recovery attachment instead of hardware.
Click to expand...

I know it's an older post, but is a perfect one for me to see. I was just considering the exact same concept using a 29mm estes retainer to hold a sled for an eggfinder. I just wasn't sure if it would fit or not. Now I can move along with that part of the build.
 

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