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airforcetp1991

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I've had really great luck making my own custom eye bolts and all thread using mcmaster 7k series aluminum rod. Best of all I can adapt it to be multifunctional in the electronics bay by having the eyebolt machined directly onto the threaded rod I use to hold everything together. The only reason I prefer Ti in something like this is it's lower interference compared to Al with electronics.
What do the eyebolts end up looking like?
 

fyrechaser

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"On a similar note I am going back and forth with regard to screw vs. rotary switches. I have used both before and I like the smaller size of the crew switches but I feel there is a limited amount of torque you can put on them. I like that the rotary switches have a positive detent and they can be mounted such that Z axis acceleration of launch/coast is inline with the armed position."
In a project like this I would be afraid to use a rotary switch. I have used them and seen them fail. I went to screw switches and have never looked back. I use the ones from Aerocon Systems and they are pretty much bulletproof.

https://aeroconsystems.com/cart/switches/pcb-screw-switch/
 

fyrechaser

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Well, somehow I messed that post up but anyway just follow the link. My apologies for that :rolleyes:
 

airforcetp1991

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You can get eye nuts that fit threaded rod. If you don't have the machining capability https://www.mcmaster.com/eye-nuts as small as 1/4-20.
That was my thought as well. I saw Wildman sells them as well so I think I might include one of his with my order and then see if it is significantly different than something like McMaster.
 

airforcetp1991

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Well, somehow I messed that post up but anyway just follow the link. My apologies for that :rolleyes:
Haha no worries. I like the setup of that switch much better. I am certainly not an electrical expert but it seems to be more robust. Have you even used these switches, they seem to have good reviews on other threads?


-Tony
 

fyrechaser

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The FingerTech switches look really nice but I have not used them. I have a good supply of the Aerocon switches that I bought years ago so I'm still using them. Good luck with your project!
 

airforcetp1991

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The FingerTech switches look really nice but I have not used them. I have a good supply of the Aerocon switches that I bought years ago so I'm still using them. Good luck with your project!
Thank you. The motor hardware should be here next month and I can really start prototyping then. Just my opinion but a project always feels more real to me once I have the motor/hardware in hand.

I like the buy a bunch and use them for a long time once you know they work mindset. Seems like companies always go out of business right when you need more of something.

-Tony
 

plugger

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Haha no worries. I like the setup of that switch much better. I am certainly not an electrical expert but it seems to be more robust. Have you even used these switches, they seem to have good reviews on other threads?


-Tony
I've not used the rotary switches for years but I've seen issues with them. The orientation of the soldering connections is a bit frustrating and I've had them knock and break before.
I've moved to those fingertech switches for anything requiring a small amount of space. MissileWorks screw switches are nice as well but I have lost one of the screws out of them driving home from a launch. If you buy them buy the screw retainer or whatever it's called? Sorry, their store seems down at the moment.
The best thing I can say about the fingertech switches (besides their size) is that the hex screw used in them feels very taunt in the unit. It almost feels as though you're turning a gear when you tighten them down. I prefer that tactile feedback when compared to other screw switches that don't have that feel.
 

airforcetp1991

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I've not used the rotary switches for years but I've seen issues with them. The orientation of the soldering connections is a bit frustrating and I've had them knock and break before.
I've moved to those fingertech switches for anything requiring a small amount of space. MissileWorks screw switches are nice as well but I have lost one of the screws out of them driving home from a launch. If you buy them buy the screw retainer or whatever it's called? Sorry, their store seems down at the moment.
The best thing I can say about the fingertech switches (besides their size) is that the hex screw used in them feels very taunt in the unit. It almost feels as though you're turning a gear when you tighten them down. I prefer that tactile feedback when compared to other screw switches that don't have that feel.
I am really happy to hear that about the Fingertech switches. That is exactly what I was hoping they would feel like compared to the much slimmer profile screw switches. My biggest concern is the long descent and if the nosecone is getting twisted and jerked around during that time I could see a slim switch screw backing out.

The magnetic switches seemed like a great idea when I first saw them and I have thought about using them for a nose cone tracker only bay to avoid having to turn it on internally but I just don't know that I trust them. Seems like a elegant solution to a problem that doesn't necessarily exist given other solutions. That said I have never tried to put a complex AvBay into a sub 38mm tube so it could just be my ignorance of the magnetic switch utility.

-Tony
 

plugger

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The magnetic switches seemed like a great idea when I first saw them and I have thought about using them for a nose cone tracker only bay to avoid having to turn it on internally but I just don't know that I trust them. Seems like a elegant solution to a problem that doesn't necessarily exist given other solutions. That said I have never tried to put a complex AvBay into a sub 38mm tube so it could just be my ignorance of the magnetic switch utility.

-Tony
Yea, I've still got a Featherweight Magnetic Switch sitting in a esd bag from when I bought a few years ago. They're great on the bench but I find on the flight line waving a magnet around and NOT hearing the FC power up isn't ideal. It's quite frustrating in fact.
 

airforcetp1991

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Yea, I've still got a Featherweight Magnetic Switch sitting in a esd bag from when I bought a few years ago. They're great on the bench but I find on the flight line waving a magnet around and NOT hearing the FC power up isn't ideal. It's quite frustrating in fact.
I love Featherweight products, I have 2 Raven4s and their tracker is incredible, I just don’t like the magnet idea. I would also be unsure of how to mount them to have 2 switches and not turn the first one off while trying to turn the second one on.

The Wifi switch made by Eggtimer seems like a cool concept, heard a lot of good things about it. My only concern with the Wifi and magnet concepts is are they truly off if they need to sense a wifi signal or respond to a magnetic field? I am happy to be corrected on this and I do not mean to act like I know more than those companies but given larger rockets can have 3+ grams of BP it is something I personally worry about. I’m here to learn.

-Tony
 

cerving

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Eggtimer WiFi switches are Tripoli and NAR approved replacements for mechanical switches. Plus you get the battery voltage, you can arm your rocket from over 100' away, and if you get the "standard" WiFi Switch you can get your deployment continuity too.
 

airforcetp1991

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Eggtimer WiFi switches are Tripoli and NAR approved replacements for mechanical switches. Plus you get the battery voltage, you can arm your rocket from over 100' away, and if you get the "standard" WiFi Switch you can get your deployment continuity too.
Well said. Is there any way to buy the wifi switches already assembled? I have become an ok solderer when it comes to wiring but I have never assembled something like this. Does the deployment continuity feature only work with your altimeters or will it work with any brand?

-Tony
 

plugger

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I love Featherweight products, I have 2 Raven4s and their tracker is incredible, I just don’t like the magnet idea. I would also be unsure of how to mount them to have 2 switches and not turn the first one off while trying to turn the second one on.
As do I. Looking at their web store I can see that I have every one of their products excluding their tracker. I've been flying them for well over a decade. My Raven 1 still works and passed bench testing a few weeks ago (I'll be using it this season).

I'm just not a big fan of magnetic switches full stop.
 

airforcetp1991

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As do I. Looking at their web store I can see that I have every one of their products excluding their tracker. I've been flying them for well over a decade. My Raven 1 still works and passed bench testing a few weeks ago (I'll be using it this season).

I'm just not a big fan of magnetic switches full stop.
What LiPo batteries do you normally use? I'm trying to find a good option, I've used 9V's until this point.

-Tony
 

plugger

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What LiPo batteries do you normally use? I'm trying to find a good option, I've used 9V's until this point.

-Tony
For most applications I use the recommended small Tenergy 138mAh 1s LiPo with the MCX connector. I bought a bunch of MCX connector cables from HobbyKing so I could build common rails for the Raven to use them. I don't believe you can make your total footprint much smaller.
 

cerving

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Well said. Is there any way to buy the wifi switches already assembled? I have become an ok solderer when it comes to wiring but I have never assembled something like this. Does the deployment continuity feature only work with your altimeters or will it work with any brand?

-Tony
We don't sell them assembled, but there are some people that will assemble them for you. The continuity feature works with virtually any altimeter... we have connection diagrams posted on our web site for some common devices.
 

airforcetp1991

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For most applications I use the recommended small Tenergy 138mAh 1s LiPo with the MCX connector. I bought a bunch of MCX connector cables from HobbyKing so I could build common rails for the Raven to use them. I don't believe you can make your total footprint much smaller.
Are those the ones on the featherweight website? I certainly like the small footprint these allow for. Have you ever had issues with their run time? My concern on a project like this is some longer ground time due to driving back from the launch tower and having to get the range ready, then a longer descent time in cold temps at altitude. Once I have more exact sled dimensions I can see how much space I have to work with.

-Tony
 

airforcetp1991

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We don't sell them assembled, but there are some people that will assemble them for you. The continuity feature works with virtually any altimeter... we have connection diagrams posted on our web site for some common devices.
Awesome, thank you.
 

airforcetp1991

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Re-learned some lettering in Solidworks and added an approximate chute and Mako object in the coupler.

-Tony

Pic11.JPG
 

plugger

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Are those the ones on the featherweight website? I certainly like the small footprint these allow for. Have you ever had issues with their run time? My concern on a project like this is some longer ground time due to driving back from the launch tower and having to get the range ready, then a longer descent time in cold temps at altitude. Once I have more exact sled dimensions I can see how much space I have to work with.

-Tony
Yea, similar, but I bought Turnigy Nano-tech 130mAh batteries from HobbyKing as they're cheaper when compared to purchasing direct from Featherweight. I've never had any issues with them at all. Runtime is a non-issue, I've used them in back to back flights before without swapping in between. Plenty of juice for dual deploy.
 

airforcetp1991

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Yea, similar, but I bought Turnigy Nano-tech 130mAh batteries from HobbyKing as they're cheaper when compared to purchasing direct from Featherweight. I've never had any issues with them at all. Runtime is a non-issue, I've used them in back to back flights before without swapping in between. Plenty of juice for dual deploy.
Nice, I will check those batteries out. That would have been my next question with the DD current capacity but that sounds great.

-Tony
 

airforcetp1991

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Yea, similar, but I bought Turnigy Nano-tech 130mAh batteries from HobbyKing as they're cheaper when compared to purchasing direct from Featherweight. I've never had any issues with them at all. Runtime is a non-issue, I've used them in back to back flights before without swapping in between. Plenty of juice for dual deploy.
Looks like these are what you’re talking about?

 

plugger

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Looks like these are what you’re talking about?

Correct. The ones I got were 130mAh but it appears they've been superseded by those 150mAh models.
If you're worried you can bench test them with some grain of wheat bulbs and see how many times you can do a simulated flight (with dual deploy) before the bulbs stop lighting up. I've never done it to exhaustion myself but I have done it three times in a row off a single battery and the bulbs lit every time.
 

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The magnetic switches seemed like a great idea when I first saw them and I have thought about using them for a nose cone tracker only bay to avoid having to turn it on internally but I just don't know that I trust them.
I think they are underrated. Once you get use to their operation they are pretty solid. I have had multiple Mach flights up to 2.2, high G flights up to 137G, and a few violent deployments and they have never failed me (my poor wiring almost has). But yes, they are not as easy as a screw switch, they require more wires, they are more expensive, and you should make the outside where the switch is so you can easily arm/disarm. They excel at not needing an arming hole and not being affected by CF parts. But all switches have there place and I used rotary, screw, mag, and wifi in different situations.
 
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