AV bay access slot

[JJenkins]

I am new to dual deployment and am building a Darkstar Jr fiberglass kit. I was considering adding a slot in the AV bay to charge the battery without disassembling the AV bay. I attached a rendering of what I have in mind. My idea is to have a y harness between the battery or connect a charge lead off the battery side of the switch. Would this cause any issues with deployment?

 

[0011001100]

I should be fine but I would be worried about ejection gases getting into that slot since the coupler fit won't be airtight. If you could use this design but add some internal ridges to accept a hatch that can be screwed on for flight, and then opened for charging afterwards.

 

[David_Stack]

There is always this option:

https://www.rocketryforum.com/threads/what-did-you-do-rocket-wise-today.48649/page-1113#post-2196366
(all credit to OverTheTop)

 

[Titan II]

Put the slot on the switch band and cover for flight.

 

[rfjustin]

I am new to dual deployment and am building a Darkstar Jr fiberglass kit. I was considering adding a slot in the AV bay to charge the battery without disassembling the AV bay. I attached a rendering of what I have in mind. My idea is to have a y harness between the battery or connect a charge lead off the battery side of the switch. Would this cause any issues with deployment?

Would the slot be on the drogue side?

 

[Steve Shannon]

I am new to dual deployment and am building a Darkstar Jr fiberglass kit. I was considering adding a slot in the AV bay to charge the battery without disassembling the AV bay. I attached a rendering of what I have in mind. My idea is to have a y harness between the battery or connect a charge lead off the battery side of the switch. Would this cause any issues with deployment?

What you propose could certainly be done. Personally, I like to inspect my altimeters, clean off any ejection charge residue, and verify for myself that everything is shipshape.

 

[cerving]

I know there's the camp that says that opening up your AV bay just gives you more things that can fail, but I don't buy that. I believe you should open it up before every flight, check for loose wires (terminal block screws can loosen in flight), check for any gas intrusion that may require cleaning up, etc. If you don't have to do anything, great, if you do find something then you may have just saved your rocket.

 

[JJenkins]

I should be fine but I would be worried about ejection gases getting into that slot since the coupler fit won't be airtight. If you could use this design but add some internal ridges to accept a hatch that can be screwed on for flight, and then opened for charging afterwards.

Good point, did not realize the ejection gases have that much ability to go everywhere.

 

[JJenkins]

Would the slot be on the drogue side?

It could be on either side. Planning on screw switch in the middle and battery leads toward the center.

 

[MikeT]

I know there's the camp that says that opening up your AV bay just gives you more things that can fail, but I don't buy that. I believe you should open it up before every flight, check for loose wires (terminal block screws can loosen in flight), check for any gas intrusion that may require cleaning up, etc. If you don't have to do anything, great, if you do find something then you may have just saved your rocket.

Agreed 100%.

 

[Tim51]

Good point, did not realize the ejection gases have that much ability to go everywhere.

If you put a camera on your rocket and freeze frame the footage at just the right moment, you'll see that even 1.5g BP makes a heck of a lot of smoke (and sometimes you'll catch a momentary sheet of flame also ) You'll also find a thin film of residue over bulkplates, terminal blocks and interiors of airframe tubing.

 

[FMarvinS]

I am new to dual deployment and am building a Darkstar Jr fiberglass kit. I was considering adding a slot in the AV bay to charge the battery without disassembling the AV bay. I attached a rendering of what I have in mind. My idea is to have a y harness between the battery or connect a charge lead off the battery side of the switch. Would this cause any issues with deployment?

In order to gain access to the lipos and altimeters without compromising the appropriate in flight altimeter baroreceptor readings, you may want to consider a variant of the av bay I previously added to an earlier thread: https://www.rocketryforum.com/threads/how-to-easily-view-lcd-screen-in-an-av-bay.143018/

 

[BDB]

Is the goal to make it easy to recharge the battery? An alternative would be to make the battery so it can be charged without removing it.

 

[Handeman]

If you don't want to disassemble the av-bay, I would say, use non-rechargeable batteries and only open the av-bay when you need to replace them. I've found that 9V batteries with simple dual deploy altimeters will last a good 3 years.

 

[JW562]

I am in a similar boat, I glued my vent band to my coupler BEFORE getting my sled and my screw switches land lower than my band. I drilled (2) 7/32” holes below my band to activate the altimeters, my plan was just to slap some thin tape over the holes to mitigate any potential issues. Should be fine, right ?

 

[Voyager1]

I know there's the camp that says that opening up your AV bay just gives you more things that can fail, but I don't buy that. I believe you should open it up before every flight, check for loose wires (terminal block screws can loosen in flight), check for any gas intrusion that may require cleaning up, etc. If you don't have to do anything, great, if you do find something then you may have just saved your rocket.

I totally agree with this! I can never understand why anyone would not want to fully check out their avbay before every flight.

 

[kramer714]

Couple of things I don't like about your plan,

• Ejecton charge residue is corrosive and conductive. Really bad combofor inside your av bay. No way to seal that easily with slot.
• You should get many flights with a battery. Simple 9v or a 2s 400ma gives me at least 5 flights over a few months without a recharge. How often do you need to go it the bay?

 

[FredA]

I totally agree with this! I can never understand why anyone would not want to fully check out their avbay before every flight.

Why - to see the insides looking for what????
If the unit powers up and reports valid battery voltage and pyro status, what more is you "visual" doing?

If you built a sturdy unit with proper wiring practices, you're taking it apart to look at components that tell you nothing.....sorry, just don't see the point......

Now - if you have done something nasty to the rocket, then yes, a total inspection is in order.....beyond that, you're wasting time IMHO.