Mounting the Raven 3 altimeter

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Mark Roberts

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I have a Featherweight Raven 3 altimeter with the hardware and two circular circuit boards to fit into a 1.5" diameter body tube AV bay. What is the recommended way of mounting this assembly in a rocket for a dual-deploy flight? If I use the standard approach of using the AV bay as a tube coupler with an ejection charge attached to each end, the circuit boards would be exposed to ejection gases. I must be missing something. Any suggestions?
Thanks,
Mark
 
I have a Featherweight Raven 3 altimeter with the hardware and two circular circuit boards to fit into a 1.5" diameter body tube AV bay. What is the recommended way of mounting this assembly in a rocket for a dual-deploy flight? If I use the standard approach of using the AV bay as a tube coupler with an ejection charge attached to each end, the circuit boards would be exposed to ejection gases. I must be missing something. Any suggestions?
Thanks,
Mark
It only gets exposed to the ejection gases when we forget to seal the holes on the bulkheads. I use plastitack to seal the holes. And I put in on my checklist so I don’t forget.
 
The Raven AV bay bulkheads will be exposed to ejection charge gasses, but that’s what they were designed for. The all thread and nuts will corrode of you don’t clean them after the flight. Other than that, not a problem.
 
Thanks Joe and Bill. OK, I will run with it as you describe. I might throw in a bit of dog barf to lessen the exposure. I will clean the circuit board bulkheads after flight. Would vinegar on a rag do the trick?
 
Thanks Joe and Bill. OK, I will run with it as you describe. I might throw in a bit of dog barf to lessen the exposure. I will clean the circuit board bulkheads after flight. Would vinegar on a rag do the trick?
Mark, I’ve not felt the need to clean an altimeter after a flight unless I left a hole open so that BP residue found its way inside the av bay. This whole thread hasn’t made a lot of sense to me, so let me make sure we’re communicating. I generally (that’s always) put one or two altimeters in the coupler that connects the booster with the payload bay, unless it’s head end deployment, in which case the coupler connects the booster with the nose cone. The coupler has a bulkhead on each end. I drill holes in the bulkhead for wires to run through. I seal those holes with plastitak. There are also holes for threaded rod and an eye bolt, but those holes are sealed by a washer and a nut. In smaller rockets, I like to connect the ematch directly to the altimeter and use a glove tip or something similar to contain the BP and the ematch. In larger rockets I use a BP well, but then run the ematch directly into the well. I also like to masking tape to protect the quick link, the nuts, the eye bolt, and the shock card from BP. When I‘ve need to clean an altimeter, I use alcohol, not vinegar.
 
Joe, In my case, the "bulkheads" on the AV bay are the circular circuit boards that are connected to the Raven (as shown in the link to featherweight altimeters in David Stack's reply to my first post). I am not worried about exposure of the Raven to ejection gases. I am, however, worried that the circuit boards will be damaged by the ejection gases.

I think you are describing a setup in which the AV bay bulkheads are solid plywood or fiberglass.
 
Joe, In my case, the "bulkheads" on the AV bay are the circular circuit boards that are connected to the Raven (as shown in the link to featherweight altimeters in David Stack's reply to my first post). I am not worried about exposure of the Raven to ejection gases. I am, however, worried that the circuit boards will be damaged by the ejection gases.

I think you are describing a setup in which the AV bay bulkheads are solid plywood or fiberglass.
OK, now it’s making more sense to me. I agree that I think I would clean up the circuit board after the launch.
 
Bill, Thanks for the photo. Mine is looking just like yours. You and the others on this thread have been a real confidence builder!

One more question about wiring the charges: According to the Raven instructions, for a standard dual-deploy setup, the leads for the main are connected to the "Main" (M) and "Arm Out" (A) terminals on the active bulkhead and the drogue leads are attached to the "Arm Out" and "Apo" terminals on the passive bulkhead. Does that sound right?

By the way, I realized that I have a Raven 2, not a Raven 3. I think the setup is the same for both.

Mark
 
Bill, Thanks for the photo. Mine is looking just like yours. You and the others on this thread have been a real confidence builder!

One more question about wiring the charges: According to the Raven instructions, for a standard dual-deploy setup, the leads for the main are connected to the "Main" (M) and "Arm Out" (A) terminals on the active bulkhead and the drogue leads are attached to the "Arm Out" and "Apo" terminals on the passive bulkhead. Does that sound right?

By the way, I realized that I have a Raven 2, not a Raven 3. I think the setup is the same for both.

Mark
The terminals are correct. But since the threaded rods make each terminal accessible from both ends, which bulkhead it is will depend on whether you have the active or the passive side facing into the main chute compartment.
 
Adrian, Thanks for your reply. I'm following the setup as shown in the instructions sent to me by David in his post of Monday (link below).

https://www.featherweightaltimeters...510427/38mm_instructions_june21_lower_res.pdf
This shows the threaded rods attached to the active bulkhead, which is the bulkhead that faces the main chute compartment. I assume that the main ejection charge should be wired to the "Main" and "Arm Out" terminals on this bulkhead.

Now, how about the passive bulkhead? Should the ejection charge for the drogue (apogee) chute be connected to the "Arm Out" and "Apo" (I assume Apo means apogee) terminals?

Mark
 
Adrian, Thanks for your reply. I'm following the setup as shown in the instructions sent to me by David in his post of Monday (link below).

https://www.featherweightaltimeters...510427/38mm_instructions_june21_lower_res.pdf
This shows the threaded rods attached to the active bulkhead, which is the bulkhead that faces the main chute compartment. I assume that the main ejection charge should be wired to the "Main" and "Arm Out" terminals on this bulkhead.

Now, how about the passive bulkhead? Should the ejection charge for the drogue (apogee) chute be connected to the "Arm Out" and "Apo" (I assume Apo means apogee) terminals?

Mark
Yes, that's correct.
 
Adrian,
I am not having success communicating between my Raven 2 and my computer via the FIP program. Typically, I get a warning message, "You have an invalid configuration that is not written to the altimeter. Do you want to close without saving?"

Any thoughts?

Thanks, Mark
 
I'm glad I have you guys to turn to. I'm going to be doing a DD with a LOC Forte so some advice on particular altimeters would help. I'm excited about it, but want to research it first before just diving in not knowing anything.
 
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