The Avionics Bay Thread...Post your Photos!

[user 30299]

I like that hexagonal design. I have the 3" Punisher kit which is designed for the HED setup. And I would like to get two flight computers and a GPS unit in the coupler sleeve. Where are the batteries located? How are they mounted?

 

[wsume99]

I'm reading this thread because I'm researching the exact same thing you are trying to do. My next HP build is a 3" Punisher and I want full redundancy plus GPS tracking all inside the coupler. This thread has been awesome to help me learn.

I like that hexagonal design. I have the 3" Punisher kit which is designed for the HED setup. And I would like to get two flight computers and a GPS unit in the coupler sleeve. Where are the batteries located? How are they mounted?

 

[mpitfield]

I'm reading this thread because I'm researching the exact same thing you are trying to do. My next HP build is a 3" Punisher and I want full redundancy plus GPS tracking all inside the coupler. This thread has been awesome to help me learn.

I like that hexagonal design. I have the 3" Punisher kit which is designed for the HED setup. And I would like to get two flight computers and a GPS unit in the coupler sleeve. Where are the batteries located? How are they mounted?

I think you are asking me about my 4" BlackFly HED AV bay hexagonal sled. Three batteries are mounted on the sled, indicated as white rectangles in picture three. These are relatively thin Polymer Lithium-Ion batteries with a nominal 3.7V at 850mAh or 900mAh, and designed for the specific AltusMetrum products. In the third picture, you can clearly see one on the right, and the other two are not in view, but, you can envision the surfaces they mount to by eliminating the two altimeters (blue) and one TeleGPS (brown).

Below are two pictures that were taken from a previous version of the BlackFly hexagonal sled. This version was replaced with the white one that included integrated wiring for the switches and one of the JST battery connectors, which can be seen in the top left of the fifth and last pictures. I also adjusted the placement of the holes for the cable ties to relieve some tension on the batteries, and I removed the antenna straw rubber cap and filled the end with epoxy.



BTW I designed a completely different sled for a 3" HED Punisher. I may have some completed pics to post, for now I grabbed some screenshots of it from my TinkerCAD files. It used four larger 2S LiPos and three devices, an Eggfinder Mini Tracker, the Eggfinder Proton with a separate battery dedicated to the Pyro channels and the StratoLogger 100. The switches were initially two mini screw switches and two magnetic switches. This sled was printed, assembled, tested and the rocket was launched once, then the sled was torn apart because I didn't like how the sled and tracker antenna were mounted. I also decided to use bulkhead mounted terminal blocks instead of pass-through holes for the e-matches. Based on the circuitry for the Proton, the second magnetic switch to power on the pyro channels was not necessary, so the revision will only have three switches.

 

[user 30299]

Thank you Michael for the photos and renderings. All I can say is your design is ingenious. I'm not a 3D-printer person yet - but I have family that create items for me at times. Your AV module, "sled" is too crude to describe your design, appears to have refined (smooth) surfaces and not the rough surfaces I usually see. Is that because of the material, the printing programs, or the printer make (design) ? And is your module design available for tinkering with? I have some of the same electronics and batteries, but others would require some minor changes to your AV module. And then of course I could use your design as an excuse to purchase some new electronics. Martin Q.

 

[BSNW]

I think you are asking me about my 4" BlackFly HED AV bay hexagonal sled. Three batteries are mounted on the sled, indicated as white rectangles in picture three. These are relatively thin Polymer Lithium-Ion batteries with a nominal 3.7V at 850mAh or 900mAh, and designed for the specific AltusMetrum products. In the third picture, you can clearly see one on the right, and the other two are not in view, but, you can envision the surfaces they mount to by eliminating the two altimeters (blue) and one TeleGPS (brown).

Below are two pictures that were taken from a previous version of the BlackFly hexagonal sled. This version was replaced with the white one that included integrated wiring for the switches and one of the JST battery connectors, which can be seen in the top left of the fifth and last pictures. I also adjusted the placement of the holes for the cable ties to relieve some tension on the batteries, and I removed the antenna straw rubber cap and filled the end with epoxy.

View attachment 404194 View attachment 404195 View attachment 404196

BTW I designed a completely different sled for 3" HED Punisher. I may have some completed pics to post, for now I grabbed some screenshots of it from my TinkerCAD files. It used four larger 2S LiPos and three devices, an Eggfinder Mini Tracker, the Eggfinder Proton with a separate battery dedicated to the Pyro channels and the StratoLogger 100. The switches were initially two mini screw switches and two magnetic switches. This sled was printed assembled tested and the rocket was launched once then torn apart because I didn't like how the sled and tracker antenna was mounted. I also decided to use bulkhead mounted terminal blocks instead of pass-through holes for the e-matches. Based on the circuitry for the Proton, the second magnetic switch to power on the pyro channels was not necessary, so the revision will only have three switches.

View attachment 404197 View attachment 404198
View attachment 404199 View attachment 404200

All I can say is that is AMAZING. All this stuff is amazing. I too am learning so much and getting new ideas. This is too cool. I wish I had a 3D printer....All I can do is hope that somebody will design and sell the hexagon sled set-up. Wow....I am blown away by all these different designs....did I say I am amazed?
Andrew

 

[Mugs914]

I agree Andrew, some real creativity out there! I've got my bandanna up around my face and I'm fixin' to steal a whole bunch of ideas!

This was a great idea for a thread, thanks for getting it started...

 

[BSNW]

I agree Andrew, some real creativity out there! I've got my bandanna up around my face and I'm fixin' to steal a whole bunch of ideas!

This was a great idea for a thread, thanks for getting it started...

Thank you for you kind words Mike-
I too am getting out my ruler, taking measurements and taking lots of notes..........HA!
wow...

 

[mpitfield]

All I can say is that is AMAZING. All this stuff is amazing. I too am learning so much and getting new ideas. This is too cool. I wish I had a 3D printer....All I can do is hope that somebody will design and sell the hexagon sled set-up. Wow....I am blown away by all these different designs....did I say I am amazed?
Andrew

Thank you Michael for the photos and renderings. All I can say is your design is ingenious. I'm not a 3D-printer person yet - but I have family that create items for me at times. Your AV module, "sled" is too crude to describe your design, appears to have refined (smooth) surfaces and not the rough surfaces I usually see. Is that because of the material, the printing programs, or the printer make (design) ? And is your module design available for tinkering with? I have some of the same electronics and batteries, but others would require some minor changes to your AV module. And then of course I could use your design as an excuse to purchase some new electronics. Martin Q.

I have two Prusa MK3S printers, or I should say 1.9 as the second needs some parts. The Prusa is arguably one of the better FDM printers on the market, but it is also one of the more expensive consumer grade printers. If you want to know more then hit up the 3D Printer section https://www.rocketryforum.com/forums/3-d-printing-and-related-topics.190/ Chuck has a lot more hands on with different manufactures and models, so he is a good resource to ask about value.

The print just looks smooth due to my bad photography abilities. It is smoothish, but that depends more on the resolution of the printer, assuming you have it dialed in, and choice of filament. I used .2 resolution, three perimeters, and PETG. I prefer PETG over PLA, although some have issues printing PETG, so it's not for everyone, but that may have more to do with the quality of PETG.

I am happy to create a copy of any of my designs and send you a PM link to the design in TInkerCAD. You will need an account and to log in, once logged in you can copy and paste the project to a new project in your projects, and then you can mess around with it at your discretion. Just send me a PM if anyone is interested.

 

[tollyman]

I have a design set up to put an eggtimer quark and eggfinder mini gps in a 38mm nosecone for my Wildman darkstar Jr. 3D printed sled and will use push toggle switches to activate the altimiter. Will post pictures when I get the design printed out and assembled.

 

[g.pitts]

A bit more progress. I have the altimeters built and wired up, and have mounted the Eggfinder TX. Got the antenna support pretty close (by luck!). Planning to put 1/32" adhesive-backed foam on the support and securing the antenna with a couple of zip ties. Altimeters will be secured by nylon fasteners, not the stainless ones used just for this photo.


Closer view of the Eggtimer Quantum stickers. Anyone recognize the font I used?

 

[mpitfield]

Very nice, clean layout. You are inspiring me to take a shot at designing my first distribution board.

A bit more progress. I have the altimeters built and wired up, and have mounted the Eggfinder TX. Got the antenna support pretty close (by luck!). Planning to put 1/32" adhesive-backed foam on the support and securing the antenna with a couple of zip ties. Altimeters will be secured by nylon fasteners, not the stainless ones used just for this photo.
View attachment 404398

Closer view of the Eggtimer Quantum stickers. Anyone recognize the font I used?

View attachment 404399

 

[wsume99]

BTW I designed a completely different sled for a 3" HED Punisher. I may have some completed pics to post, for now I grabbed some screenshots of it from my TinkerCAD files. It used four larger 2S LiPos and three devices, an Eggfinder Mini Tracker, the Eggfinder Proton with a separate battery dedicated to the Pyro channels and the StratoLogger 100. The switches were initially two mini screw switches and two magnetic switches. This sled was printed, assembled, tested and the rocket was launched once, then the sled was torn apart because I didn't like how the sled and tracker antenna were mounted. I also decided to use bulkhead mounted terminal blocks instead of pass-through holes for the e-matches. Based on the circuitry for the Proton, the second magnetic switch to power on the pyro channels was not necessary, so the revision will only have three switches.

Definitely interested in seeing pics of your 3" Punisher sled if you have any. I have a 3D printer so I was already planning on using it for this project. Still capturing ideas. I already have an Eggtimer classic and would add an Eggtimer mini tracker and StratoLoggerCF and three (possibly 4) LiPos. The hexagonal design is appealing since I am planning to run a single all thread down the middle of the AV bay. I am assuming you have the switches aligned with your vent holes on your switch band?

 

[g.pitts]

I received some good constructive feedback from a couple of forum members, so I've made a change to my electronics bay configuration. Eggfinder TX tracker is now in the nosecone on its own printed sled, and the electronics bay sled holds only the two Quantum altimeters as shown below. I added switches that can be used to select "always on" or on when the switch lever is not depressed (strapping option - no strapping has been installed yet). Given the new Tripoli rule, I suspect that "always on" mode won't be used. There will be a 3D printed cover mounted by the four center screws which will serve to guide a small metal rod to "safe" the rocket and to prevent anything that may come loose during flight from inadvertently hitting the switch lever and power-cycling one or both of the altimeters.

 

[Viperfixr]

A bit more progress. I have the altimeters built and wired up, and have mounted the Eggfinder TX. Got the antenna support pretty close (by luck!). Planning to put 1/32" adhesive-backed foam on the support and securing the antenna with a couple of zip ties. Altimeters will be secured by nylon fasteners, not the stainless ones used just for this photo.
View attachment 404398

Closer view of the Eggtimer Quantum stickers. Anyone recognize the font I used?

View attachment 404399

Where does that center, purple board that consolidates the charges come from?

 

[g.pitts]

Where does that center, purple board that consolidates the charges come from?

It is a printed circuit board that I designed, and had fabricated through OSH Park.

 

[spigalau]

Looking great.

 

[kbRocket]

Has anyone managed to mount two altimeters in a 38 mm AV bay? I'm trying to figure out a way to get two Eggtimer Quantums into the 38 mm x 6" coupler for my Blackhawk 38. I think I can do it, but it will be TIIIIIIIGHT!

I have put redundant dual-deploy with tracking into a 29 mm Av Bay. Three Electronics Bays
The trick was eliminating the threaded rods and using a sufficiently stiff sled/backplane.

A long time ago I did fit an RRC3 and an Easy Mini into a traditional 38 mm Madcow electronics bay with threaded rod, so I know it's possible. I wouldn't do it that way any more.

 

[Rocketbegg]

This caps with eletronics components stay inside the rocket all time?

 

[g.pitts]

Update on my progress posted here for my trackers, and here for the electronics bay sled design. I'm calling this good for my L2 certification flight, which will peak at 7Gs so nothing too crazy in terms of loading on the components.

 

[CoyoteNumber2]

Sled for a 54mm nose cone. Camera, Raven3, RTx/GPS, two screw switches, three batteries (300, 160, 750 mAH respectively.)

 

[OZRoc]

Finally finished modifications to a 3" GL Vertical Assault.

2 x SLCF's with output resistors on a 3D printed sled. 1 switched via the original rotary switch and the other using an ET WiFi switch.

2 x 950ma Batteries in 3D printed holders. All battery connections swapped out from JST to Doghouse (Binder Design) locking connectors. Redundant charge wells manufactured from old TV antenna tubing. I'm using centrifuge vials as the ejection charge containers.

Charge well ends flared using my old fridgy tools. Centre punch deformations just inside the throats hold wells in place. No glue. Wire exit ends of the wells castellated with a dremel, bent over, epoxied and drilled.
When all this crisis is over I might actually be able to check it all out.
Cheers, Mark

 

[Donnager]

I'm using centrifuge vials as the ejection charge containers.

I had some fuzzy thoughts after seeing some 3d printed charge containers, and wondered why you might not move the wells into the body of the E-bay to avoid re-bound of parts damaging lightweight charge containers. I had no serious thoughts about really doing this until seeing yours.

Looks like you could make the same with some tubing, a flare tool, and either a cap or a pinched end, brazed, soldered, or glued.

Nice design.

 

[strud]

I'm mid way through putting together my bay for a 4" hybrid powered vehicle, where this bay is sitting within the nosecone and acting as the coupler between NC and top section of airframe. Main chute is within NC and drogue below coupler.

Going with dual flight computers (raven 4 and one of my own) + home brew digital telemetry board (GPS + IMU + 1W digital radio modem + Rocket supervisor (home brew) with ESP32 module + SA818 radio module + DTMF + GPS rx to implement APRS.

Trying to minimise mass wherever possible since this is going in a PoC vehicle where I'm trying out a number of concepts prior to a more ambitious set of flights.

Main differences from my previous bays:
- Integrated ejection charge cannon tubes
- Increased mounting surface area board/battery carrier
- focus on reduced mass while maintaining load bearing capacity (going with hand made aluminium attachment points, fasteners and tie rods)
- inclusion of a power monitoring isolation switch, giving the ability to see both battery voltage and current consumption when on the pad prior to launch and during flight)

currently working on -
- attaching switch band
- install power isolation switch
- mount boards & batteries
- installing SMA RF connectors into bulkheads/end caps (using 1/4 x 36 tapped holes)

Will post pics as I progress

 

[strud]

Have installed RF connectors (SMA) using 1/4 x 36 tpi tapped holes

On one end I'm using bulkhead cable assemblies

The other using bulkhead connectors with female both sides

Shown installed with switch band installed in top airframe tube (Nose cone not installed)

Sitting free

Next steps:
- battery isolator build and install
- mount PCBs
- mount batteries
- finish machining harness attachment points

 

[OverTheTop]

Buried charge wells work, er, well .



These were machined on my lathe. The grove on the outside lets an o-ring hold the Kapton tape in place. Once you have flown it once it can get a bit difficult to get the tape to stick again. O-rings give certainty.

Further info here: https://forum.ausrocketry.com/viewtopic.php?f=6&t=5019&start=60

This was for a 4" airframe.

 

[OverTheTop]

Closer view of the Eggtimer Quantum stickers. Anyone recognize the font I used?

Arial .

We now know the access codes to your alts too .

 

[strud]

Hey OTT

Is the 4 pole connector on yours for the charges?

If so, how are you sealing that to prevent the charge pulse and crud coming into the bay? (glue/sealant ??)

i'm procrastinating about what sort of connector or terminals to use on mine, but I have to on at least one end so I can assemble the thing.

 

[OverTheTop]

Correct Strud. They are Molex Microfit 3.0 series connectors. Nice positive locking and quite cheap and reliable. I seal around the base of the connector with hotmelt to stop gases bypassing the header into the avionics area. The plug and receptacle are given a good dollop of CG53 (Electrolube) contact grease internally which keeps the gases from getting through the connector and also keeps the BP residue off the contacts. I usually tape over the top of the connectors with Kapton tape too, just for a bit more mechanical protection.

The example I posted above is able to remove the top plate which can aid assembly. Here is another example of a removable endplate using similar style connectors. It allows assembly and then fitting the endplate. This is a 3" version. It also has extra switches, for interlocking, and passthrough for HEI of the sustainer.

I should also note that the power supply voltages are fed out of this assembly on the larger black connecotr on the left. They go to the TeleMega in the nosecone, via a separable cable. The four spare deployment channels in that are used to monitor the power to these altimeters in the regular downlink telemetry. There is nothing like confidence in the power before you push the launch button . Loss of those voltages also signals nosecone deployment.

The two connectors on the left are mounted on a piece of G10 so the endplate can be removed.
More details here: https://forum.ausrocketry.com/viewtopic.php?f=6&t=5019&start=75

 

[Bindhammergroup]

A bit more progress. I have the altimeters built and wired up, and have mounted the Eggfinder TX. Got the antenna support pretty close (by luck!). Planning to put 1/32" adhesive-backed foam on the support and securing the antenna with a couple of zip ties. Altimeters will be secured by nylon fasteners, not the stainless ones used just for this photo.
View attachment 404398

Closer view of the Eggtimer Quantum stickers. Anyone recognize the font I used?

View attachment 404399

Excellent work. Working on a 54mm sled presently with little room. Would like to incorp the clean and snazzy connectors used in your bay. Where did you procure those used for drogue and mains? Thanks

 

[g.pitts]

Excellent work. Working on a 54mm sled presently with little room. Would like to incorp the clean and snazzy connectors used in your bay. Where did you procure those used for drogue and mains? Thanks

Thank you! I've iterated it quite a bit since that particular posting, but the connectors used in those photos are JST JWPF family. Here are the links on DigiKey:

• PCB Connector
• Inline Connector
• JST pre-crimped "jumpers"

Are you planning to design a PCB for your electronics bay? I did it mostly to cleanup the wiring, and it cleaned things up nicely (in my opinion at least).