I like how this is laid out.....I also see you too mounted your switch on the side by the all thread....if I would have done this on mine, I would have had more room....maybe to put a GPS on my sled as well. Love the photos guys.....keep them coming as I am sure I am not the only one getting new or fresh ideas from others!Here is mine
The terminals were epoxied to the bulkhead with J B Weld. I never had a problem. I used a pair of xmas bulb with the wires that provide continuity when the filament burns out removed and the two bulbs hot glued into a paper wound tube and 24" of wire soldered to the bulbs. The BP was added, the tube folded over and taped. They all worked fine at about $0.05 per charge. When I started using ematches, I laid them on a piece of duct tape, poured the BP over the match, folded the tape and sealed everything together. That also worked perfectly.I like your design and your use of the snap switch. Did you epoxy or superglue the screw terminals to the bulk heads? How well did the screw terminals hold up to BP over the course of several launches?
That's a lot to "squeeze" into a 4 inch long 38 mm bay. You may want to consider buying a 6 inch or longer bay to have enough room. If the space for your chute is too limited, you can also purchase (or cut) a 2 to 3 inch vent band to acquire some more room. Good luck!I'm currently working on a bay for a LOC IQSY Tomahawk. Trying to fit an Eggtimer Quark and a Turnigy 2C LiPo in a 38mmX 4" coupler. Right now it's not looking very elegant. If I get it looking half way presentable I'll post some pictures of the finished product. Working on adding a pull pin switch, but I might give that idea up in favor of the old "Twist and Tape". I'm planning to just put the charges in glove fingers. For terminals I used 4-40x1" screws and brass nuts.
Really nice job, Curtis!Posted in another thread, but here you go
worked with David Fliger on designing some custom av bay lids, which he manufactured. The altimeter came out great. Kudos to him and several other TRF vendors.
Here are the design points:
· 4-inch diameter bay configurable in 7.5-inch and 11-inch length sleds
· Tinder Raptor CO2 system on the main chute
· Eggtimer Proton and Quantum altimetee
· LabRat Rocketry pull switches
· RocketJunkies machined wire feedthrough on both ends
· RocketJunkies charge cups
· RocketJunkies custom bulkhead
· AltusMetrum Telemetrum transmitter/triple backup altimeter Eggtimer Tx transmitter for tracking
· Two or three Lipo batteries in 3d printed battery box holder (depending on configuration)
· 3d printed sled with a rounded edge to lay on the outside edge of altimeter compartment
· 3d printed guillotine clamp to keep the D-ring from knocking into CO2 assembly
· Antenna SMA connector port
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Nicely done! That hexagonal sled is a clever way to use virtually all of the volume in your bay.This is for my 4" Mac BlackFly, which uses a HED (Hed End Deployment) AV Bay. FOr those who are not familiar with that design. It is essentially taking the coupler from the nosecone and turning it into the AV Bay, and putting the main in the nosecone. The first time I saw the term HED, and the design, was on Jim Hendricksen's 3" Wildman Punisher.
I designed this rocket to accommodate the Loki 54-2800 case, so I had to recess the AV bay in the 8" coupler by about 4". This is a pic looking at the bottom of the bay. I used redundant BP canisters for apogee deployment.
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This is the top end of the AV Bay. I used a single CO2 Raptor, with redundant e-matches, for main deployment. The Tracker (Altus Metrum TeleGPS) antenna, exits the top bulkhead through an RC antenna straw and is sealed at the end with epoxy. You may notice the red/blue bulkheads. I started doing this a number of years ago, just as a quick reference for when assembling. I got the idea from my kid's EpiPens. An EpiPen has a blue cap on top, and an orange base. The instructions say "blue to the sky and orange to the thigh". In my case, I went with "blue to the sky and red to the flamy end," Poetry is not my thing.
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The AV Bay sled was designed using TInkerCAD and 3D printed. It is a fully integrated design with wire management, switches, batteries and altimeters.
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Side view showing one of the altimeters (Altus Metrum Easy Mini) and tracker. You can see one of the FingerTech screw switches on the bottom. There are three of these, and they line up perfectly with the sampling holes in the AV bay band.
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Here is a pic of the tracker showing the through bulkhead antenna straw. I added some heat shrink tube around the last 1.5" to give a bit of strength to where it interects with the bulkhead. You can see the bottom end of the CO2 cartridge, which screws into the center of the sled
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I used a y harness connected directly to the U-bolts for the recovery harness on both ends. The threaded rods go through the center of the U-bolts and sled, the other bulkhead U-bolts centers.
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Here is a clear pic from the bottom, showing the CO2 cartridge and the screw switches.
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To connect the aft wiring harnesses to the through bulkhead terminals, I use min deans connectors. These connectors work very well for this purpose, although they are a bit challenging to solder.
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Assembling this AV is not very easy. However, it is well sealed and firmly held together once the fight is over.
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I am very particular with all my AV Bays and I put them through worst-case, unrealistice bench testing, while being held in the vice.
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What are your design goals - full redundancy? Switches to turn on the electronics? LiPo versus 9V? Etc. How much of your 6” coupler is actually usable (interference from bulkhead hardware, etc)? That would help bound the problem.Has anyone managed to mount two altimeters in a 38 mm AV bay? I'm trying to figure out a way to get two Eggtimer Quantums into the 38 mm x 6" coupler for my Blackhawk 38. I think I can do it, but it will be TIIIIIIIGHT!
I have a CF 38mm Mongoose, and I looked at doing a fully redundant AV bay. However, in the end, I decided to take the easy route. So I used an RRC2+ altimeter with one of the Missleworks screw switches mounted on one of their 3D printed sleds. I have to redesign the bulkheads this winter and I may revisit a custom 3D printed dual bay setup.Has anyone managed to mount two altimeters in a 38 mm AV bay? I'm trying to figure out a way to get two Eggtimer Quantums into the 38 mm x 6" coupler for my Blackhawk 38. I think I can do it, but it will be TIIIIIIIGHT!
Several years ago, a MD screamer came in ballistic ~10’ from my wife. I want to be sure I get separation, so I’m looking for full redundancy.What are your design goals - full redundancy? Switches to turn on the electronics? LiPo versus 9V? Etc. How much of your 6” coupler is actually usable (interference from bulkhead hardware, etc)? That would help bound the problem.
Yikes - that’s scary. Glad no one was injured in the ballistic event!Several years ago, a MD screamer came in ballistic ~10’ from my wife. I want to be sure I get separation, so I’m looking for full redundancy.
Here’s my thinking on a dual-altimeter 38 mm AV bay. I think I could get by with twist-and-tuck to alleviate the need for switches. Since I’m hoping to use the Quantums, this would just power them up; they would still be armed remotely by WiFi. The key to the plan is the nano-tech 300MAh 2S lipo.
It’s tight, but I think it will work. I’m planning to build two new Quantum’s for this project, and I think I’ll solder leads to the boards instead of the screw terminals to save a little more space.
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Well, I've got a finished product that I'm pretty sure is going to work. I don't have a collection of advanced tools at my disposal so this is not as elegant as some. The battery just gets stuffed in under the sled, it doesn't even need to be secured, there's no room for it to go anywhere.That's a lot to "squeeze" into a 4 inch long 38 mm bay. You may want to consider buying a 6 inch or longer bay to have enough room. If the space for your chute is too limited, you can also purchase (or cut) a 2 to 3 inch vent band to acquire some more room. Good luck!
Looks good-if the lipo bounces around too much, you could zip tie it to the back of the sled and run the lipo leads through a hole drilled into the sled.Well, I've got a finished product that I'm pretty sure is going to work. I don't have a collection of advanced tools at my disposal so this is not as elegant as some. The battery just gets stuffed in under the sled, it doesn't even need to be secured, there's no room for it to go anywhere.