First time av bay

So this is my first time building an av bay, and I've got a few questions... This may get lengthy, but any help would be great.
... See the picture... Oh, and this is going in a 3" DarkStar

1) does it matter which way the RRC2+ is facing? I should have mounted it to the right of the RRC3, but woops... If I spin it around, it'll be easier to mount the wires since that's where the block is.
2) my plan is to mount the two batteries one behind the other using cable ties for attachment. Any thoughts on this?
3) my plan is to connect the e-matches directly to the altimeters, knot the wire on the inside of the av bay to prevent pulling, and use either the glove tip method or maybe the surgical tube. No terminal blocks or charge wells on the av bay lids. I've got poster putty to seal the holes. Any thoughts on this method? I'm thinking it'll just be more straight forward for a newb at DD.
4) Based on the setup in the picture, what do I need to know or think about?
... I'll be bringing this with to the next club launch to ask the same questions, and I don't plan on launching DD, but if I've got it all ready and it gets the okay after a little help, I just may go for a DD flight...
I'm extremely nervous about it cause I'm not really sure what I'm doing. Hate that feeling when I've got hundreds of dollars and lots of man hours involved in the project...

1. No

2. I also wrap the battery and connector with electrical tape to maintain a good connection. Use at least three tie wraps each. Two horizontally and one vertically.

3. Using glove tips without a well directly wired to the altimeter using poster putty is what I do. Simple and reliable. I would not knot the wire. If you feel you need strain relief, use a small tie wrap on the wire inside the bay.

You are doing a nice job and picked top notch altimeters.

Thanks! ... Another question... I just got around to plugging in the RRC3. No beeps, no nothing. Both batteries worked fine to power up the RRC2+. Am I missing something or do I have a defective RRC3?

Dumb question but are you using a switch or twist & tuck method?

CzTeacherMan said:

No beeps, no nothing. Both batteries worked fine to power up the RRC2+. Am I missing something or do I have a defective RRC3?

Click to expand...

Well, let's start with the simple stuff: First, is battery polarity correct? Second, have you connected anything to the "Switch" terminals? You'll need to put a jumper between those, or a switch, or pair of wires to twist, in order to complete the circuit and apply power to the altimeter.

You'll get it going, I'm sure. Take your time.

Mark

CzTeacherMan said:

So this is my first time building an av bay, and I've got a few questions... This may get lengthy, but any help would be great.
... See the picture... Oh, and this is going in a 3" DarkStar

1) does it matter which way the RRC2+ is facing? I should have mounted it to the right of the RRC3, but woops... If I spin it around, it'll be easier to mount the wires since that's where the block is.
2) my plan is to mount the two batteries one behind the other using cable ties for attachment. Any thoughts on this?
3) my plan is to connect the e-matches directly to the altimeters, knot the wire on the inside of the av bay to prevent pulling, and use either the glove tip method or maybe the surgical tube. No terminal blocks or charge wells on the av bay lids. I've got poster putty to seal the holes. Any thoughts on this method? I'm thinking it'll just be more straight forward for a newb at DD.
4) Based on the setup in the picture, what do I need to know or think about?
... I'll be bringing this with to the next club launch to ask the same questions, and I don't plan on launching DD, but if I've got it all ready and it gets the okay after a little help, I just may go for a DD flight...
I'm extremely nervous about it cause I'm not really sure what I'm doing. Hate that feeling when I've got hundreds of dollars and lots of man hours involved in the project...

Click to expand...

1) never used the RRC2+ or RRC3 but I would tell you what others may, which is to carefully read the manufactures instructions. I know there are some devices that have an up or down and if mounted incorrectly can have a negative effect.
2) cable ties can work, but if you have stand-offs, preferably nylon ones, although metal will work as well, then I would use a stand off. It will keep the electronics in one place as the G forces can move things around and the last thing you want is the electronics to fail because a wire got pulled.
3) your method is the simplest design, plus it introduces the least amount of resistance, which if unchecked can cause failures.
4) not sure what type of adhesive you used to stick the sled to the all-thread or whatever it is you used, to the sled. If you are confident in it then great but you could also drill some small holes and zip-tie the sled to be sure it will not break free

I think its great that you're going down this road and I wouldn't get too discouraged about trying DD. When I got into HPR I went right to electronics from my first launch and have used DD since. Remember all of us have to try it to gain the experience. I think you are totally on track by asking advice and stick with tried methods. The important thing is that you are enjoying yourself and comfortable with what you are doing.

My question has to do with the physical design of the av-bay. Is you sled going to leave plenty of area for the air to flow from one side of the board to the other? If the sled effectively divides the bay, the vent holes and internal pressure from one side of the sled to the other can be affected.

1st: relax. You've asked good questions and haven't screwed anything up. This is your first venture into this; give thyself a break and realize this is how the process begins. As you develop your own preferences and techniques, you'll find out what works best for YOU. As others mentioned with the RRC 3, it requires a switch, and you can make one with a jumper wire or two wires twisted together, or an actual switch you intend to use. The battery power goes to the marked terminals in the board (minding the + to the + and the - to the -), and the switch to its terminals. The RRC2+, you've got to put the switch inline. Have you considered what switches you'll be using?
2nd: There's nothing inherently wrong with your intent with the batteries. I'd place them on the back of the board, personally, but I worry about them breaking free and smacking into the circuit board. This, mind you, has never happened to me, so it may be an irrational fear, but... that's why I put them on the back, regardless. Easiest, quickest way to securely attach 9vs, in my opinion, is to mount them terminal-side down, drill 4 holes in the sled around their perimeter and place zip ties through the sled, around the battery crossways and longways, in so doing, clamping the terminal to the battery. After use, simply cut the zip ties and unplug them. True, this wastes zip ties. Good news: you get a quarter bazillion of them at Harbor Freight for laundry change.
3rd: Your e-match plan will work.
4th: Based upon the picture, I'd say you should consider wearing shoes in the shop. Heh.



Later!

--Coop

Thanks! I was wondering if I needed a "switch" wire on the 3... I'll try that.
The board has JB Weld holding it on the two aluminum tubes that slide over the all thread. I'll be cutting off the excess FG to help with airflow and make it so the sled can fit in a smaller an bay. 2.6" should be easy.
No, I don't wear shoes in the shop. I used to wear sandals but who knows wear they went. Maybe after I drop something on my toes I'll change. I'm a pain-based learner... ;-)

Okay, doing a twist on the switch terminal worked. Sweet. Now I'm getting excited.
Oh, another question... How in the heck does one test these things? I've read lots of ideas, so do me a favor and condense that info for me here. Because you guys rock.
Thanks!

Recommend you just put a direct jumper on the switch circuit and use twist and tape on the battery circuit to activate/deactivate the unit. The RRC3 has a test function in the manual. I use Christmas tree lights. Did you get the dongle to program the RRC3 and download data by computer?

I did not get the dongle. Bought it back on black Saturday, and my wife was already threatening to take away my credit card... LoL
Any reason to do twist and tape directly with the battery?
Attached a picture of the setup. Altimeters are mounted on nylon standoffs, by the way.
Now all I need is black powder...

Load your starting charges for drogue & main. Pack your laundry, ensure you have an empty motor case installed (stuff it with rags if your using a CTI case). From this point, I bypass the altimeter & just feed an e-match lead thru a vent hole. All you have to do is just touch the e-match leads to a 9 volt battery and "bang". Adjust charge as necessary. That's it in a nutshell. Do this outside of course! I'm sure there are other methods but I find this one pretty simple.

I like to prepare rockets well in advance and want to completely sever the battery circuit. Basically, it ends up like the RRC2+. Tim is on target regarding testing the ejection charges. BTW...budget the dongle...you will not regret it.

I have an RRC3 and it beeps at power up. Also it is preset so you can fly out of the box I believe. I would check the switch as well. Jim at Missleworks is very good about helping , I needed my hand held through a project and he was great

I'm digging the syringe charge as well, but hear it is hard on cardboard so keep for FG rockets.

Your batteries will work fine stacked, but I would also tape and s few Zips as well

To test a barometric altimeter, you need to simulate take off, apogee, and descent. Adept Rocketry sells a test jar that is very nice, and inexpensive. Wire the altimeter to the leads, hook up a battery to the outside leads, drop it in the jar, seal the lid, draw back on a syringe (this sucks out the air and simulates take off), hold the syringe in place (this simulates apogee), slowly let the air back in (this simulates descent).

You'll need two LEDs and two resistors that will light up when your drogue and main charges fire. Not only is this a good test tool, but it is also educational.

https://adeptrocketry.com/VCK2-VACBOTds.htm

You think a Tupperware container sealed with duct tape would work?

If you have a Foodsaver, you can use the marinade bowl to test your altimeters, instead of igniters use Christmas tree bulbs (mini-bulbs), I place the whole unit, battery, RRC3 and everything into the bowl put the lid on it and fire up the foodsaver. Sorry I don't have pictures of the process however my bowl is similar to this:

Instead of Christmas tree bulbs, I use a couple of LEDs. Just remember that LEDs (unlike light bulbs) do need to be installed with the polarity correct.

I made a jar like what Adept sells. It's simply a pint Mason jar that I put drilled a hole in the lid. I put an aquarium tubing connector in the hole and sealed with silicone caulk and pull a vacuum using a marinade injector syringe. As you push in the plunger of the syringe, you can see the 2 events trigger by watching the LEDs.

I can also use this for testing the charges (if I care to put the altimeter in the mix) by running the charge lines (20 ft of 26 ga wire) out another hole in the lid.

Total cost of this was $0, as I made it from stuff lying around the house.

CzTeacherMan said:

You think a Tupperware container sealed with duct tape would work?

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Yep, as long as you can fit the altimeter, battery, and christmas lights inside, get a good seal, and find or fabricate a way to create a vacuum and release it.

(A straw and 5-min epoxy works just swell).


Later!

--Coop

The only problem with LEDs is that they're not a resistive load, so they look like a dead-short to the altimeter (assuming the polarity is correct). They really don't like much current either, you put 1A through one and it's going to pop like a flashbulb. You're much better off using Christmas tree lights; a $3 string from Wally World will last you a lifetime.

cerving said:

The only problem with LEDs is that they're not a resistive load, so they look like a dead-short to the altimeter (assuming the polarity is correct). They really don't like much current either, you put 1A through one and it's going to pop like a flashbulb. You're much better off using Christmas tree lights; a $3 string from Wally World will last you a lifetime.

Click to expand...

Or do it right and attach a proper resistor to the LED. I have a nice LED-and-resistor-on-leads used just for troubleshooting testing electronics

cerving said:

The only problem with LEDs is that they're not a resistive load, so they look like a dead-short to the altimeter (assuming the polarity is correct). They really don't like much current either, you put 1A through one and it's going to pop like a flashbulb. You're much better off using Christmas tree lights; a $3 string from Wally World will last you a lifetime.

Click to expand...

Hmm. I've used the same pair of LEDs for about a dozen tests and haven't had one pop. Didn't know about the dead short condition. Maybe I should have paid a little more attention in the electronics class I had to take.

Bat-mite said:

https://adeptrocketry.com/VCK2-VACBOTds.htm

Click to expand...

What a simple and inexpensive kit...I may just have to pick one up.

AlfaBrewer said:

Hmm. I've used the same pair of LEDs for about a dozen tests and haven't had one pop. Didn't know about the dead short condition. Maybe I should have paid a little more attention in the electronics class I had to take.

Click to expand...

If you have the kind in a housing used for panel mounting they often have a dropping resistor built into the assembly. Bare LEDs aren't going to be able to take more than about 50-100 mA before they pop.

So what are everyone's thoughts on drilling an extra hole for the twist and tape wires to pull through? I figure I can tape right over the hole to maintain the three evenly spaced vent holes.

CzTeacherMan said:

So what are everyone's thoughts on drilling an extra hole for the twist and tape wires to pull through? I figure I can tape right over the hole to maintain the three evenly spaced vent holes.

Click to expand...

Should not be a problem either way.

CzTeacherMan said:

So what are everyone's thoughts on drilling an extra hole for the twist and tape wires to pull through? I figure I can tape right over the hole to maintain the three evenly spaced vent holes.

Click to expand...

Do it frequently...works fine.

markkoelsch said:

Should not be a problem either way.

Click to expand...

Titan II said:

Do it frequently...works fine.

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Yep, that's what I do. As a matter of fact, I used the switch wire hole as the alignment hole for one of the sections on my L3 rocket. Just don't tape the wires to the part that separates
Don't ask me how I know...
As to mounting the RRC2+ and RRC3, any orientation will work.

Adrian

I just run my wires right thru 1 of the vent holes and either tape wire to vent band or payload. Never had a problem.