Dual Deployment Layout Recommendations

bchaltraw

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I am working on laying out my Dual Deployment and think I have a plan. Going to use an RRC3 and a RRC2L, Went with the Rocket Junkies Alum charge wells, and have three different switches on the way to see which ones I like better. Screw/Push/Schurter?? Here is what I have laid out so far, also planning on doing a forged eye on the end of the single 1/4" all thread I am using. That saves space on the end caps and I think the shock cord pulling on the all thread would be more uniform than the bulkhead.
IMG_0825.jpeg
Will be using an RRC2 but don't have it yet so just cut out an RRC3 template for ideas.
IMG_0818.jpeg
 

wsume99

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I would leave more room between your charge wells and the terminal blocks. Basically move the charge wells to the 10 and 2 position from where you have them now which I'd call 9 and 3. It will work as-is but it can be a pain to get the e-match leads into the terminal block so a little more room will make that easier.

Switches - There are several options for how to interrupt the power to your altimeters. I use screw switches. The only option I would avoid using is a Schurter rotary switch. I've never used them personally but reading the forums you will see at least one altimeter OEM advising against it. Lots of people use them and have for years without issue. They just don't seem like a good idea to me so I don't use them. You can make your own determination.
 

QFactor

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Have you considered moving the batteries to the backside of the sled? I find this gives me a little
more maneuvering room for the flight controllers - along with their wiring and switches.

I also like to have my batteries separate from the electronics. Just incase one breaks loose it's not
thrashing around destroying everything. The batteries in the photo only had a single zip tie for
when I was mocking up the bay. Each gets two additional zip ties for a launch.

IMG_7667.JPG IMG_7682.JPG

Your sled looks like it's maybe for a 3" or 4" rocket. The above is a 5.5" rocket. I have 3" and 4" bays with the 9-volt
batteries on the backside.

The switches in the photo are Fingertechs. But I also use the regular screw and rotary switches.

In your photo, be sure the battery's terminals are pointing down toward the fins if you use a battery holder.
Less chance of the battery pulling away from the holder's terminals due to the launch forces.
 

bchaltraw

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It is indeed a 4" rocket. I, unfortunately, bought the sled from Apogee and it's a single all-thread one, having the single rod running up the middle makes it tight to get batteries on each side of the rod. I have looked at doing that also, but have not tried to see what the clearance will be as you might be able to see how the sled is offset and I do not know if there is room yet to put 9v batteries and not hit the tube. Rod would differently hit a LiPo battery if mounted on the backside. More parts are showing up this week, once I have them all I can start placing them and see how it goes. Thank you for help.
 

QFactor

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It is indeed a 4" rocket. I, unfortunately, bought the sled from Apogee and it's a single all-thread one, having the single rod running up the middle makes it tight to get batteries on each side of the rod. I have looked at doing that also, but have not tried to see what the clearance will be as you might be able to see how the sled is offset and I do not know if there is room yet to put 9v batteries and not hit the tube. Rod would differently hit a LiPo battery if mounted on the backside. More parts are showing up this week, once I have them all I can start placing them and see how it goes. Thank you for help.

If you look in my photos you will notice the electronics sit on the "top" of the sled. So the "tighter" clearance to the av-bay
tube is with the electronics. The battery side has the greater clearance because the sled sits "below" the threaded rod.
9-volts and their holders always need a little more headroom. That may be the case with your sled.

You're on track though. Get all the parts, mock it up. and then you'll know.
 

Black Bart

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Chris of Eggtimer recommends staying away from 9 volt battery's. I used 2 S1 LIPO 350mv battery's in series. This is a 55mm Apogee e bay with a Eggtimer Quark.
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kramer714

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Agreeing with other comments;
1) The batteries look pretty close to the terminals on the altimeters, Wires coming out of the terminal strips dont like to have serious bends right next to the terminals.

1A) try turning the batteries 90 degrees if you need more room, either side by side or on the back side so the 'skinny side' is against the sled.

2) Agreeing wit the comment about moving the charge wells farther from the terminals, lots of options, position the terminals on opposite sides of the bulkhead, or move the charge holders. I wouldn't be too worried about maintaining symmetry. You can move the charge holders to one side for example.

3) think about cable management. good to drill some 'extra holes' to be able to tie the wires down. Think about how you will need to open the avbay to remove it and how you will disconnect the wires to one of the bulkheads.

4) I use microswitches, and a screw for av bays. I use 3d printed avbays, simplifies this a bunch with the microswitches.

5) Think about how you will keep the eyebolt from unscrewing. Lots of different ways of achieving this, i personally dont count on a swivel doing this for me. simple second screw and a piece of lock wire works, cotter pin also works....

Mike K
 

bchaltraw

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Agreeing with other comments;
1) The batteries look pretty close to the terminals on the altimeters, Wires coming out of the terminal strips dont like to have serious bends right next to the terminals.

1A) try turning the batteries 90 degrees if you need more room, either side by side or on the back side so the 'skinny side' is against the sled.

2) Agreeing wit the comment about moving the charge wells farther from the terminals, lots of options, position the terminals on opposite sides of the bulkhead, or move the charge holders. I wouldn't be too worried about maintaining symmetry. You can move the charge holders to one side for example.

3) think about cable management. good to drill some 'extra holes' to be able to tie the wires down. Think about how you will need to open the avbay to remove it and how you will disconnect the wires to one of the bulkheads.

4) I use microswitches, and a screw for av bays. I use 3d printed avbays, simplifies this a bunch with the microswitches.

5) Think about how you will keep the eyebolt from unscrewing. Lots of different ways of achieving this, i personally dont count on a swivel doing this for me. simple second screw and a piece of lock wire works, cotter pin also works....

Mike K
To keep the eye bolt from swiveling, I originally thought to get my safety wire pliers I used in the military out of retirement, but think of drilling a small hole like for a cotter-pin but use Jesus clips so they are easy to pull. If you don’t know what a Jesus clip is, it’s a spring clip, we called them Jesus clips because you broke one that’s what you would be saying when it hits the fan. Lol
 
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kramer714

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I have used both of those doesn't take much to keep it from spinning. Another method I have done with aluminum or fiberglass bulkheads is to make a notch in the flange of the eye nut ( I use a Foredam grinder with a small end mill in it, or can do it with a file or a rotary grinder) and drill a small hole offset from the eyebolt as a hard lock. Tap the hole or a nut on the other side. I use #6 because I 'stock those' but a #4 would be plenty.

For safety wire I use a screw with a launch lug as an 'anchor point'.

1669908354808.png
1669909010796.png
 
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Handeman

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Lab Rat Rocketry Pull Pin switches are the easiest to use, bar none. No screw drivers needed, no magnets needed. Just pull the pin to arm, replace the pin to disarm.

I've gotten back to using pull pins on all my av-bays. I also use a screw switch in series with the pull pin that is accessed through the shoulder that fits into the booster section. That way I can turn off the altimeter and load matches and powder and prep the whole rocket, without the pull pins getting in the way, getting bent, or breaking the switches. After everything is ready, the last thing before heading to the RSO, the pull pins are inserted and the screw switches are turn on and the rocket is closed up.

I recommend positioning the screw switches near the switch band. If you get to the pad and pull the pins and nothing happens, it's because you forgot to turn on the screw switches. Having them near the switch band means you only have to lift the av-bay a little ways out of the booster to turn them on. Been there, done that, and have the t-shirt!
 

bchaltraw

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Have you considered moving the batteries to the backside of the sled? I find this gives me a little
more maneuvering room for the flight controllers - along with their wiring and switches.

I also like to have my batteries separate from the electronics. Just incase one breaks loose it's not
thrashing around destroying everything. The batteries in the photo only had a single zip tie for
when I was mocking up the bay. Each gets two additional zip ties for a launch.

View attachment 548420 View attachment 548421

Your sled looks like it's maybe for a 3" or 4" rocket. The above is a 5.5" rocket. I have 3" and 4" bays with the 9-volt
batteries on the backside.

The switches in the photo are Fingertechs. But I also use the regular screw and rotary switches.

In your photo, be sure the battery's terminals are pointing down toward the fins if you use a battery holder.
Less chance of the battery pulling away from the holder's terminals due to the launch forces.
What is the antenna you have for your GPS? That’s a slick setup. I have been looking at putting mine in the nosecone.
 

OverTheTop

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Remember that for cable wrangling you can glue wires to the sled in spots using a hot-melt glue gun. I prefer a slightly more permanent solution and tack them down with CA glue. You can chisel it off later for modifications if needed.
 

QFactor

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What is the antenna you have for your GPS? That’s a slick setup. I have been looking at putting mine in the nosecone.

Here are some pictures of the bulkhead antenna. This rocket has two T3 GPS units; avionics bay and nose cone.
The bulkhead antenna has a clear tubing sleeve to give it extra protection from the BP charges. I've included a
picture of the antenna with its Part #. Both T3 setups worked perfect in an L3 launch to 10,000 ft.

There are lots of good GPS nose cone designs/builds on TRF. John Coker has a good video.

IMG_7885.JPG IMG_7914.JPG

IMG_8005.JPG IMG_8018.JPG


IMG_8050.JPG IMG_6257.JPG


I just picked up a new super stubby antenna. Here are some pictures. I'm hoping to get some test flights in soon.
This stubby antenna has good specs for Gain, but it's only mono pole.

Stubby-915MHz-Antenna-02.JPG Stubby-915MHz-Antenna-01.JPG
 
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