I use a lot of this type switch and never remove the screw. Any concern it can close during transportation can be easily mitigated. It is discussed in this thread.
All, I wanted to share a safety concern that I have encountered. I have a rocket that utilizes these PCB mount screw switches. Twice now, I have had the rocket arm itself during transit. I keep my Av Bays prepared and in the house until it's time to transport as I don't want to expose my...www.rocketryforum.com
BTW...thanks for your work John.
Correct. I do that on all of mine.these look to be similar to missileworks screw switches
I have found that the screw is slightly loose in the nut and giving it crimp to slightly damage the threads makes it tight and so it will not vibrate loose
I would be concerned with noise and bouncing in all cases: when off, turning on, when on, and turning off. If the electronics being used is immune to say 1s of noise or bounce, then all tested switches would pass.I appreciate the testing. I'm not sure why time to turn on and noise while turning on are important in our application. We turn electronics or initiator circuits on, once, and time on should be irrelevant unless it is in minutes. Could you elaborate on why you feel they are important?
Maybe. However, they are not the same. The Featherweight switch is rigid (PCB-based) while the Fingertech has a flexible Nylon body.Since the physics of the Fingertech is similar to the Featherweight switch, if the behavior in turn on and noise is significantly different, I'd suspect the test setup.
The rating is indeed subjective. I could certainly change my mind if we learn more about the sensitivity of common electronics.I would think that for our application, vibration and shock should be paramount. If a switch starts generating noise or bounce when it is supposed to be connected, that is a show stopper. That is why I think the Schurter and Featherweight belong at the bottom of the list.
Both actually. Here's my "0" test (all switches off) at 500Hz. Note that purple is #5 (the Featherweight screw switch).
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Here's my "5" test (only Featherweight on) at 500Hz. Note that blue is the Shurter.
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If anyone is interested, I can send the data files. They're saved in TDMS format, which is consumable by many programs. (I used "DAQami", which comes from the same company that made the sampler.
I tend to agree, except I travel with loaded charges in rockets in the bed of my pick up. They are all screw switches, but we'll see if that ever causes an issue. I suspect not, but who knows../
I have seen "open" screw switches vibrate intermittently closed in transit. It depends on how long the screw is, and how tight it is. Some of those screw switches have very short screws... it doesn't take much.
I used only finger strength (not making a fist); I tightened it until it was firm and no farther. Sorry, I know that's not very precise.But the lack of a solid "on" under vibration in the on state is very surprising; I haven't seen that in any of my launch data continuity voltage readings before. Do you recall how tightly you screwed it down?
I don't know the brand; I probably bought it from Mouser or maybe even Radio Shack (long ago). I also was surprised it performed as well as it did. That bent metal spring works well!Interesting data. What brand of phono jack is that? I used phono jacks for switches back in the last century, but was told they were the worst. It seemed to perform pretty well here.
That's the takeaway I get too. And certainly, with the brownout protection being more common than it was 25 years ago, it would take a switch that can be jarred to *off*, and stay there, to be a fail.A key takeaway for me (which sounds obvious in hindsight) is that traditional switches just work. I'm not sure the "special rocketry" switches really add ananything.
For years I have been recommending the NKK miniature slide switches. They’re rated for 50 gees of shock and vibration in six degrees of freedom.A key takeaway for me (which sounds obvious in hindsight) is that traditional switches just work. I'm not sure the "special rocketry" switches really add anything.
Always enjoy your videos and knowledge......
I have switched over to a Featherweight Screw switch after the NEW Schurter Power Select Switch failed before I even finished building the model.
Hopefully this Featherweight will prove great !! May try some of the tricks talked about, making the screw tighter to turn thus avoiding
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I’ve switched to using the FingerTech switches, and have had great success. My only caveat is that don’t like the supplied aluminum hex screw - I tend to bugger them up if the allen drive isn‘t well aligned. To fix this I always replace the aluminum screw with stainless screws (from McMaster).
The MS series switches from NKK in the panel mount variant (with solder lugs) are available from a couple of vendorsFor years I have been recommending the NKK miniature slide switches. They’re rated for 50 gees of shock and vibration in six degrees of freedom.
Unfortunately they’re no longer available with solder lugs on their terminals, but Cherry Switch makes some that are nearly identical. I think the Cherry Switch is what PML used to sell that they said were 50 gee rated.