The Avionics Bay Thread...Post your Photos!

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CoyoteNumber2

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Two Eggtimer Protons with a custom PCB to manage remote power, arming/indicators, and integration of two 12V solenoid latches.
Is there loss of redundancy by arming through one PCB?
 

AllDigital

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Is there loss of redundancy by arming through one PCB?
The custom PCB is 100% redundant, so it is like two boards in one. As are the altimeters and batteries. This is for a hypergolic bipropellant rocket with a computer pad controller that interfaces to this board via the rocket umbilical. The pad controller can keep the altimeters 100% powered off while fueling and pressurizing, but then they can be powered up and armed remotely with a positive signal going back to the pad MCU indicating they are armed (can't hear beeps or get wifi in bunkers). The deployment for this rocket is using 12V solenoid latches, so the PCB also has a lot of flyback and protection diodes that allow the altimeters to share a single drogue and main solenoid latch.
 

CoyoteNumber2

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The custom PCB is 100% redundant, so it is like two boards in one. As are the altimeters and batteries. This is for a hypergolic bipropellant rocket with a computer pad controller that interfaces to this board via the rocket umbilical. The pad controller can keep the altimeters 100% powered off while fueling and pressurizing, but then they can be powered up and armed remotely with a positive signal going back to the pad MCU indicating they are armed (can't hear beeps or get wifi in bunkers). The deployment for this rocket is using 12V solenoid latches, so the PCB also has a lot of flyback and protection diodes that allow the altimeters to share a single drogue and main solenoid latch.
Super cool. Do you have a thread/blog/anything about the rocket and/or pad controller?

I see you're in SoCal - I'm guessing you launch at FAR or RRS?
 

bobbyg23

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My newest avbay on the new LOC 7.5" T-LOC. Integrated into the fin assembly.
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CoyoteNumber2

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My newest avbay on the new LOC 7.5" T-LOC. Integrated into the fin assembly.
I would have thought turbulent airflow around the fins could cause faulty readings in barometric altimeters. Must not be that much of a real problem if that's where LOC decided to put the bay.
 

DarthMuffin

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gizmobay1.jpg
gizmobay2.jpg


My first av-bay. Donut bay for my 4" Wildman Gizmo. It slides over the end of the MMT and sticks up a little farther (see the lip on the inside). Eggtimer Apogee (motor eject as backup, chute on a JLCR), battery, and printed-in charge well on top (untested yet, hope it holds up). Printed in carbon fiber petg. Shock cord eye bolt threads through one of those holes, other hole is a just a holddown (and backup shock cord mount if needed).
 

bobtheshortstop

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These are all very clever and extravagant designs but can someone post a picture of a VERY basic and simplistic design? I'm getting into dual deploy for the first time and this thread was recommended to me. I'll get to this point of designs some day but it's a far reach as of now.
 

Troy3003

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These are all very clever and extravagant designs but can someone post a picture of a VERY basic and simplistic design? I'm getting into dual deploy for the first time and this thread was recommended to me. I'll get to this point of designs some day but it's a far reach as of now.
Posts 2-17 have fairly easy to follow setups for dual deploy.
 

OKTurbo

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Here’s a very basic setup on my Stiletto.
 

RocketScientistAustralia

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Posts 2-17 have fairly easy to follow setups for dual deploy.
If you've got a 10" dia rocket, you can build your AV bay from 4x2 timber, if you've got a 1" min dia rocket you've got a different set of parameters. I've made an AV bay sled from foam core board hot glued to 2 bits of plastic tube with 2 x 3mm threaded rod in between the top and bottom parts.
What rocket is it you want an easy design for? What's the parameters for the design? What tools do you have available to you?
 

bobbyg23

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These are all very clever and extravagant designs but can someone post a picture of a VERY basic and simplistic design? I'm getting into dual deploy for the first time and this thread was recommended to me. I'll get to this point of designs some day but it's a far reach as of now.
Just finished this last night. Basic as they come
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Buckeye

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Posted this in another thread, then realized this is a better place for it.

Wildman Mach2 54mm Minimum Diameter with HED. The bulk of my time and effort on this build (by a lot) was spent on the av-bay to hold a SLCF altimeter and Featherweight GPS.

I hacked an Additive Aerospace 54mm sled to hold the altimeter and its battery on one side. Note the two resistors and added terminal blocks for ematches. This is to prevent excessive current through the deployment channels as discussed here.

On the other side, in the battery compartment, is the GPS tracker and its battery. I drilled a hole through the compartment to allow the antenna to poke through. I seriously considered #10-24 nylon threaded rod to hold the bay together (because of the GPS antenna running parallel) and by some rough calculations, deemed it strong enough. However, after a bunch of GPS testing in my neighborhood, I determined that #10-24 aluminum rod wasn't hurting or attenuating the signal, and I felt more at ease with the metal connections.

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FlyBy01

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View attachment 475226View attachment 475227

My first av-bay. Donut bay for my 4" Wildman Gizmo. It slides over the end of the MMT and sticks up a little farther (see the lip on the inside). Eggtimer Apogee (motor eject as backup, chute on a JLCR), battery, and printed-in charge well on top (untested yet, hope it holds up). Printed in carbon fiber petg. Shock cord eye bolt threads through one of those holes, other hole is a just a holddown (and backup shock cord mount if needed).
Would you please consider sharing the print file for this AV-bay?
 

DarthMuffin

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Would you please consider sharing the print file for this AV-bay?
Sure, here is the tinkercad model I made it from. Sharing a link to this rather than the STL so you can more easily edit it/ungroup and change parts, etc. For example your motor mount almost certainly sits a bit higher or lower than mine. Or just export the big piece in the middle as an STL for a copy exactly as I printed it.

If I wasn't clear the two holes on the sides are for a 1/4" eye bolt on one side. Screw it down until just snug, motor case will keep it from loosening. 1/4" threaded rod on the other with a nylon (probably overkill) nut on top. 1/4" holes drilled and washers and nuts expoxied to the bottom of the forward motor mount centering ring. ematch terminals are 3mm bolts, which I happen to have a bunch of in stainless from the 3d printing hobby. Separating those two terminals a little more might be nice on a future version.

After some bench testing I can confirm the charge well works great, and holds just under 1g of BP for me which is perfect. But it's kind of hard to fill and tape off (I imagine really hard with wind in the field) so I'll probably use premade powder charges in something (glove finger, surgical tube, etc) taped to the well. The terminals for the ematch are kind of fiddly, you may need to remove the ebay from the rocket to change out. Which fortunately is really easy, although threading in the eye bolt with shock cord attached is slow.

Be sure to add nut drivers for the 1/4" nut and the ematch terminals to your field kit.

https://www.tinkercad.com/things/3MLifdikpcq
 
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