# Rotary Switch Failures?

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#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
I am retiring a few older Altimeters. So I just got a StratologgerCF as I have had great results with Perfectflite (and MissileWorks). Of course I read the warning about using the 110v/220v rotary switches.

I have used those a LOT and never had a failure. Yet the enclosed insert to the instructions seems to indicate I am wrong...

We had this same discussion on TRF (I think within the last year) and I think that you will find opinions on both sides of the aisle. Personally, I am with you. In fact I used the Stratologger last summer with the 110/220 switch and it worked fine. In fact I just bought another Stratologger. However, I did not see the insert in the first Stratologger I bought. I haven't opened the package for my latest purchase. On a slightly different subject there were people last summer that told me that they did not trust the Stratologger. I find a lot of different opinions floating around. I remember when I first advocated Q2G2 igniters and people told me I was wrong. Now the devices are so coveted you can't find them anymore.

#### Zeus-cat

##### Well-Known Member
The altimeter manufacturer is telling you not to use the rotary switches as they were not designed for a high G environment. That doesn't mean they won't work. It means that they are more likely to fail than a switch that is designed for a high G environment.

It is like the college guys who come to our field and they are launching a high power rocket with a cheap 9V battery powering their altimeter. One of the things that I tell them is to always use a good battery like a Duracell. I have seen one college guy destroy about $1,000 dollars of rocket and electronics because he used a battery from Amazon that were 8 for$10. As best as we can tell the battery failed during the boost phase as the altimeter recorded about two seconds of data. The altimeter was still functional despite a ballistic recovery (semi-functional as the connectors for the main and drogue were sheared off). Stratologgers will operate for a second or more if battery power is lost. Since it only collected data for about two seconds it apparently lost power during the boost (high G) phase of the flight. We assumed it was the battery that failed. The battery was destroyed so we can't be sure.

Doesn't everyone want a successful and safe flight? If the manufacturer is telling you not to use a rotary switch why would you want to use it? A high power rocket coming in ballistic because of a recovery system failure is a very dangerous thing. I think it is incumbent on all rocketeers to launch as safely as possible. We certainly don't need another fatality in this hobby.

#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
Thanks for the replies. Oh I 'get' it. The point is well taken. But I am not into twist and stuff. And I don't like arming anywhere other than at the pad vertical.

So if there is a thread that lists safe high G switches please point me too it.
Thanks!

#### dhbarr

##### Amateur Professional
Thanks for the replies. Oh I 'get' it. The point is well taken. But I am not into twist and stuff. And I don't like arming anywhere other than at the pad vertical.

So if there is a thread that lists safe high G switches please point me too it.
Thanks!
Fingertech Mini Power Switch is supposed to be one of the toughest / smallest, AFAIK

#### dhbarr

##### Amateur Professional
They are nice switches, but how expensive are they with shipping to the US from Canada where Fingertech is located.?
7 bux a pop from robotshop, which is US based. I couldn't estimate the shipping on Firefox mobile, but I don't guess it would be too outrageous.

#### mpitfield

##### Moderator
Staff member
Global Mod
They are nice switches, but how expensive are they with shipping to the US from Canada where Fingertech is located.?
I just purchased 10 of them and shipping was \$12.87 to get to me in Toronto.

#### markkoelsch

##### Well-Known Member
I have been using the Missileworks screw switches. I think you would have to do something truly ludicrous to break one.

#### rharshberger

##### Well-Known Member
7 bux a pop from robotshop, which is US based. I couldn't estimate the shipping on Firefox mobile, but I don't guess it would be too outrageous.
Thank you! I dont plan on buying any anytime soon but its good to know that there is a US vendor. Fingertech is located in Saskatchewan thats why I was curious about the international shipping cost.

#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
I have been using the Missileworks screw switches. I think you would have to do something truly ludicrous to break one.
I use drogue-less cable cut deployment. Given the LONG coupler length of my Rocketry Warehouse kits, I have never had an issue with drilling static holes several inches behind the nose cone and yet I have the altimeter in the nose cone. The last thing I want is to arm through a hole in the nose cone. That is a new and bad, static port. With the shurtler switch, that is not an issue. It seals the hole.

I am accepting no solution that does not do the same. I am exploring the home made screw switch using Rawl nuts.

Jeff

#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
Looking that that switch... am I the only one who started looking at plugs differently... ????

#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
I have a question.... Deans plugs... used to ARM high amp RC setups. But not by pulling... but by inserting... How might that be done with pulling?

#### dixontj93060

##### Well-Known Member
My standing offer--if anyone wants to get rid of those flakey, unreliable Schurter rotary switches PM me and I'll pay shipping.

#### Worsaer

##### Amateur Propulsionist
Thanks Tony - that there's a good list!

#### rharshberger

##### Well-Known Member
I use drogue-less cable cut deployment. Given the LONG coupler length of my Rocketry Warehouse kits, I have never had an issue with drilling static holes several inches behind the nose cone and yet I have the altimeter in the nose cone. The last thing I want is to arm through a hole in the nose cone. That is a new and bad, static port. With the shurtler switch, that is not an issue. It seals the hole.

I am accepting no solution that does not do the same. I am exploring the home made screw switch using Rawl nuts.

Jeff
Now I know what the real name for Well-nuts are, "Rawl nuts".

#### gdjsky01

##### Whoosh, pop: life is good
TRF Supporter
My standing offer--if anyone wants to get rid of those flakey, unreliable Schurter rotary switches PM me and I'll pay shipping.
But not YET gonna happen.

#### robbdm

##### Rocketry Tourist
I use the Schurter rotary switches... over 5 years, hundreds of flights no issues I only use Stratologgers.

I've add redundant switches in larger rockets and use these arming switches from binder design.

#### tbonerocketeer

TRF Supporter
I am retiring a few older Altimeters. So I just got a StratologgerCF as I have had great results with Perfectflite (and MissileWorks). Of course I read the warning about using the 110v/220v rotary switches.

I have used those a LOT and never had a failure. Yet the enclosed insert to the instructions seems to indicate I am wrong...
I think you will find the newest versions are the issue. The last batch I had felt lighter than what I remember. I wonder if they had to switch to Chinese made to be cost competitive. Now, I have had the old ones fail, though it was always on the pad. One day they just stop arming, click, no beeps. Remove the switch and they beep away.

#### Zauskycop

##### Well-Known Member
What is the verdict on the 2P SPST On-Off 1.5A Push button Switch available from MAC Performance? I like the ease of the push switch...anyone have reviews or know if these will hold up?

#### Steve Shannon

##### Well-Known Member
TRF Supporter
What is the verdict on the 2P SPST On-Off 1.5A Push button Switch available from MAC Performance? I like the ease of the push switch...anyone have reviews or know if these will hold up?

I cannot comment on the specific switch that MAC sells, but Radio Shack sold a switch that looked identical and worked identically. One of my friends flew them all the time for years until he had one come apart during use. He stopped using them.

Ask MAC for the manufacturer's data sheet. See if there's a physical shock, vibration, or gee rating.

Steve Shannon

#### djkingsley

##### Well-Known Member
I am starting to assemble my L3 avbay and I have sets of tubular key switches, Schurter rotary switches, and a couple of EggFinder WiFi switches in my parts box.

Does anyone have a read on if the EggFinder WiFi switches are acceptable for a NAR L3 Certification Flight.

My default plan is to use the tubular key switches for the L3 rocket, I have flown both the tubular key and Schurter switches in my L1 & L2 rockets.

#### Exactimator

##### Well-Known Member
I am starting to assemble my L3 avbay and I have sets of tubular key switches, Schurter rotary switches, and a couple of EggFinder WiFi switches in my parts box.

Does anyone have a read on if the EggFinder WiFi switches are acceptable for a NAR L3 Certification Flight.

My default plan is to use the tubular key switches for the L3 rocket, I have flown both the tubular key and Schurter switches in my L1 & L2 rockets.
I see no reason why the EggFinder WiFI switch would be an issue, but that's something you should confirm with your L3CC.

I would wonder more about the key switches. One of the requirements is that the ejection charges can be disabled. If someone needed to disable the charges and didn't have a key, that would be an issue. Again, something that would need to be checked with your L3CC.

Good advice I've heard on cert flights is go with what you know. Use whatever acceptable switch you're most familiar with.

#### Exactimator

##### Well-Known Member
What is the verdict on the 2P SPST On-Off 1.5A Push button Switch available from MAC Performance? I like the ease of the push switch...anyone have reviews or know if these will hold up?

I've never flown a push button switch on a rocket, but I'd be concerned about a large enough shock in the right direction accidentally activating the switch and powering off the electronics.

#### dixontj93060

##### Well-Known Member
I've never flown a push button switch on a rocket, but I'd be concerned about a large enough shock in the right direction accidentally activating the switch and powering off the electronics.
On the typical locking push-button mechanism, if you had a big enough shock to have the circuit switch, then you have bigger problems than the switch.

#### Steve Shannon

##### Well-Known Member
TRF Supporter
I am starting to assemble my L3 avbay and I have sets of tubular key switches, Schurter rotary switches, and a couple of EggFinder WiFi switches in my parts box.

Does anyone have a read on if the EggFinder WiFi switches are acceptable for a NAR L3 Certification Flight.

My default plan is to use the tubular key switches for the L3 rocket, I have flown both the tubular key and Schurter switches in my L1 & L2 rockets.
First, discuss this with your L3CC member. She or he can always bring the question to the committee.
The rule is that for your L3 rocket you must be able to physically open the circuit somewhere between the battery and the ejection charge. Does the wifi switch do that or is it a solid state switch?

#### Exactimator

##### Well-Known Member
First, discuss this with your L3CC member. She or he can always bring the question to the committee.
The rule is that for your L3 rocket you must be able to physically open the circuit somewhere between the battery and the ejection charge. Does the wifi switch do that or is it a solid state switch?
Oops, I think you're right that it's not sufficient.

Here's the portion of the NAR code regarding the disconnect:

2.4 The capability must exist to externally disarm all pyrotechnic devices on-board the rocket.In this context, disarm means the ability to physically break the connection between apyrotechnic system and its power source. Simply turning off the device controlling thepyrotechnic(s) may not be sufficient.

I was thinking of the additional step of putting a disconnect in between the altimeter and the charge. That was deemed unnecessary for modern altimeters since, when the power is disconnected from the altimeter, it can't power the charges. That doesn't apply here.