Wire and switches for E-Bay

[exprditer789]

What wire do you perfer when wiring an E-Bay.Whats the best switch to use and how do you hook that up to the altimeter?Alex

 

[quickburst]

"Whats the best switch to use".
I like these switches:
https://www.missileworks.com/index.php?main_page=product_info&cPath=2&products_id=3

"How do you hook that up to the altimeter"?
The swithch is used to turn the alt off and on. Normally it breaks the hot wire coming from the battery. Is that what you are asking?

"What wire do you perfer when wiring an E-Bay"?
I like to use 24 AWG stranded wire, be sure to tin the ends.

OCYMMV


Alex

 

[WillMarchant]

I like Dave's post except that the forum had a big discussion a month ago about tinning the ends of stranded wire being a no-no. For "good connectors" (that have a leaf spring) you just leave the twisted wire ends bare. If the screw itself contacts the wires then you crimp on a ferrule.

I also encourage people to double-check the altimeter instructions as they often have wiring instructions. Both what the connections do and what wire is recommended.

I like the missileworks switches and have used them a lot. But I miss having a "remove before flight" lanyard.

For altimeters that include a capacitor onboard to "debounce" the power switch, I'm thinking about heading back to a headphone jack and using the NC connection for the switch input. The argument against those is that the spring contact can "bounce" but if the altimeter is protected against that then you should be fine.

 

[jderimig]

I like to use 24 AWG stranded wire, be sure to tin the ends.

OCYMMV

Unless you put them in screw terminals.

Phoenix Reference here

Read section "No conductor pretreatment"

 

[Pantherjon]

Switches?:confused2: I don't use no switches! Twist and tape! It works, simple and efficient!

Twist the leads from the switch terminals together, tape, then listen to altimeter beeps and then tape to side of rocket..Or you COULD tuck it back through the vent hole into the avbay..But, taping to the side of the rocket makes disarming a lot easier if you have a misfire or ignition problem with the motor...:2:

 

[WillMarchant]

Or you COULD tuck it back through the vent hole into the avbay..But, taping to the side of the rocket makes disarming a lot easier if you have a misfire or ignition problem with the motor...:2:

I can't recommend putting the wire back inside the AvBay for the reasons PantherJon gives. If you do you should tape the exposed ends to make sure they don't short out anything if they rattle around inside the AvBay...

 

[troj]

I recently purchased a spool of 24ga stranded speaker wire -- typically need to runs of wire, anyway, and it saves the hassle of having to twist pairs together.

I like the switches from MissleWorks that Dave gave the link to.

-Kevin

 

[Rocketjunkie]

I connect the e-matches directly to the altimeter (22 gage solid) and use an extra piece for the twist and tape arming. New wires every flight.

 

[quickburst]

I like Dave's post except that the forum had a big discussion a month ago about tinning the ends of stranded wire being a no-no. For "good connectors" (that have a leaf spring) you just leave the twisted wire ends bare. If the screw itself contacts the wires then you crimp on a ferrule.

I also encourage people to double-check the altimeter instructions as they often have wiring instructions. Both what the connections do and what wire is recommended.

I like the missileworks switches and have used them a lot. But I miss having a "remove before flight" lanyard.

For altimeters that include a capacitor onboard to "debounce" the power switch, I'm thinking about heading back to a headphone jack and using the NC connection for the switch input. The argument against those is that the spring contact can "bounce" but if the altimeter is protected against that then you should be fine.

I did not know that. I think its Perfect Flite that recommends the tinning. The thought behind it is so you don't have a stray strand contact something inadvertently. I'll look around and see, but I have to admit what you are saying makes sense.

I have used the twisted wire method many times myself. I don't normally shove them back into the bay. I tape them down most of the time. I have also left them just hanging out to flutter at will. I'll have to admit it has never caused a failure or any other sort of problem.

 

[troj]

I've only had the twist & tape method cause me problems once. At Sweaty Balls II, I twisted and taped on a bay held in with plastic rivets.

On the way up, the rivets fell out (I had used them before without a problem) allowing the bay to slide, and shear the wires when the apogee charge fired.

-Kevin

 

[sylvie369]

I've only had the twist & tape method cause me problems once. At Sweaty Balls II, I twisted and taped on a bay held in with plastic rivets.

On the way up, the rivets fell out (I had used them before without a problem) allowing the bay to slide, and shear the wires when the apogee charge fired.

-Kevin

One could reasonably argue that you had trouble with the rivets, not so much with the twisted wire method.

I have mostly used the Missileworks switches, but I'm quickly moving to twisting wires together and taping them to the outside of the rocket. I'm also not a fan of shoving them inside, and it doesn't seem necessary.

 

[exprditer789]

What do the wires connect to that you connect on the outside of the rocket and tape?

 

[Sgt Blowfly]

The wires connect to the "switch" terminal on the altimeter inside the Ebay. The wire is snaked through to the outside of the airframe thru a vent hole, then twist and tape to the side of the rocket, or as mentioned earlier, you can shove it back into the ebay. This arms the altimeter.

 

[exprditer789]

Thanks for making that clear.Alex

 

[cbrarick]

McMaster Carr makes great spst push button switches if you're going to use the "thru the wall" switch method. I mount the switch upside down in the ebay so that you make the push button on the backside of the ebay. This prevents damage to important parts.

I second the use of speaker wire. Got some nice stranded wire from radio shack and I'm not certain if I'll ever run out...

 

[quickburst]

I knew I had read this somewhere.

"Do not allow an excess of bare wire outside the terminal, as it could shortcircuit to adjacent parts or wires. Always use solid wire (or tin any stranded wire ends with solder) – the loose strands in untinned stranded wire can “escape” during wire insertion and make contact with adjacent terminals."

This was clipped out of the Perfectflite MAWD manual.

Now, I don't believe that not following Peter's advice will doom your project, but I'm sure he has his reasons for the procedure. I have always tinned the ends of my stranded wire, I have also noted that if I didn't place them exactly under the terminal that they could get stuck or even damage the terminal block.

So ..... do as you see fit. What ever works for you will be the way to go.

 

[jderimig]

... Always use solid wire (or tin any stranded wire ends with solder) – the loose strands in untinned stranded wire can “escape” during wire insertion and make contact with adjacent terminals."

This was clipped out of the Perfectflite MAWD manual..

This is a very widespread and forgivable mistake because correct best practices are not widely know in this area.

More references on terminal best practices.

European Electrical Standards VDE 0611: "Means of retaining conductor strands shall be provided when terminating conductors at devices or terminals which are not equipped with this facility. Solder shall not be used for this purpose."

IPC-A-620, 4.1 Wire Preparation, Tinning. "Note: Wires intended to be secured to threaded fasteners or crimp terminations shall never be tinned."

There is a difference between making an inadvertent mistake (letting a wire strand escape) and purposely making a mistake (tinning stranded wires for screw/crimp terminals.)

The correct way to deal with the strand escape issue is to crimp a ferrule on the stranded wire and insert that into the screw terminal. I admit I don't do that either and few people do. So it gets down to a selection of which mistake you want to make.

 

[sandmantoy]

I always tin stranded wire and never had any kind of problems. I have seen a stray strand cause a short on many occasions over the years not necessarily with rocketry but I believe it to be the correct way. On larger voltage wiring connections it may be the case when using heavy gauge wire as I have seen instructions for high voltage connections with instructions to not tin the wires and for screw terminal connections to have crimped lugs installed. These where mainly on 3 phase switches and motor connections where these instructions where observed.

In fact when looking up this quoted standard you will see that it is for high voltage switch wiring and 3 phase. Minimum voltages they are using for reference is 80 volts and most are referenced to 550- 1100 volts. I would say it is safe for our 24v and less circuits are safe being tinned. I am pretty sure our rule of thumb was you don't tin wires that could get hot in a clamped situation because it can become loose and come out when the solder becomes fluid.

 

[DJDeadParrot]

For altimeters that include a capacitor onboard to "debounce" the power switch, I'm thinking about heading back to a headphone jack and using the NC connection for the switch input. The argument against those is that the spring contact can "bounce" but if the altimeter is protected against that then you should be fine.

I tried using these for a while. I found that they don't last all that long before they no longer complete a circuit when the jack is unplugged. Do they lose their 'spring'? I now have 5 or 6 rockets with an unusable phono jack built into them.

So, yeah, twist and tape for me, too.

 

[exprditer789]

Is there negative and positive wires going to the terminal blocks from the drouge and main terminals on the altimeter.When i hook the e match to the block is there a neg and pos plug in.

 

[dixontj93060]

More references on terminal best practices.
European Electrical Standards VDE 0611: "Means of retaining conductor strands shall be provided when terminating conductors at devices or terminals which are not equipped with this facility. Solder shall not be used for this purpose."

BIG, BIG MISTAKE. Do not listen to Europeans (dominated by German engineering) regarding electrical or, worse yet, computer/software engineering. They know mechanical engineering, but they are extremely weak/nearly incompetent regarding electrical/computer/software engineering. I know this from experience working in Europe for a German company. Tinning should be perfectly fine for providing a positive physical and electrical contact.

 

[troj]

BIG, BIG MISTAKE. Do not listen to Europeans (dominated by German engineering) regarding electrical or, worse yet, computer/software engineering. They know mechanical engineering, but they are extremely weak/nearly incompetent regarding electrical/computer/software engineering. I know this from experience working in Europe for a German company. Tinning should be perfectly fine for providing a positive physical and electrical contact.

...except that IPC (the second reference he listed) is an International body involved in electronic interconnects. I'd say that group is likely a bit more knowledgeable about the topic than the rocketry crowd.

-Kevin

 

[jderimig]

BIG, BIG MISTAKE. Do not listen to Europeans (dominated by German engineering) regarding electrical or, worse yet, computer/software engineering. They know mechanical engineering, but they are extremely weak/nearly incompetent regarding electrical/computer/software engineering.

Unreliable contacts due to tinning is a mechanical engineering issue not electrical.

They know mechanical engineering, but they are extremely weak/nearly incompetent regarding electrical/computer/software engineering.

Hmm.
Too bad most of US ERP systems are run by SAP (German)
Industrial controls Siemens (German)
Most popular industrial CAD system Solidworks (French!)

I could go on and on listing EU tech that has completely displaced US tech in EE and software. We're screwed.

Edit: Europeans also kick our professional golfer's butts.

 

[sandmantoy]

I would have to agree that is more of an engineering issue but as it stands the rule or standard for those instructions are for higher voltages than any rocketeer will ever need and I don't find any fault with them. Except that they are being referenced for this issue.

I have wired Machinery and facility electrical for more than 15 years as well as worked with industrial electricians replacing the 400 amp main service to one of our buildings. Those rules do apply to 110- 460 volts from what I have experienced over the years. I don't understand why they call it low voltage in there reference, maybe it has been referenced from some really high voltage rules but it does not apply here.

It makes sense that stranded wire will come loose if it heats up in a high load situation if it has been soldered when clamped down and the solder becomes fluid from the heat. Another instance is a large heavy stranded wire can come loose when when there is sufficient vibration over time, I can't remember the term for this. In a machine shop the whole building will vibrate when all the machines are running at more than half horse power, I am sure other industrial buildings will be the same.

The small gauge stranded wire we tin the ends on will conform to the clamps we use and not come loose. Try this yourself, tin a piece of stranded wire and clamp it in one of the connectors of your altimeter. Then remove it and you will see that it has been malformed by the clamp. This you can not do to a large gauge wire without just about damaging the clamp.

Sorry I rattled on about this so much lol. I truly believe tinning the small gauge stranded wire in our hobby is the correct and safest way to connect a stranded wire in a screw connector and one reason many of us have been doing it this way.

 

[dixontj93060]

European Electrical Standards VDE 0611: "Means of retaining conductor strands shall be provided when terminating conductors at devices or terminals which are not equipped with this facility. Solder shall not be used for this purpose."

There may be some confusion as to applicability here. The original Low Voltage Directive started in Europe to define connectivity/safety applied to "all electrical equipment designed for use with a voltage rating of between 50 and 1000 V for alternating current and between 75 and 1500 V for direct current" (low voltage when compared to power distribution). I am not completely sure, and don't have time to trace it back, but VDE 0611 entitled "Low Voltage Switchgear and Controlgear" seems to be an extension to this line of work at least as near as I could trace it through the parallel IEC document tree back to 1953, IEC 60947. So although it is stated to cover up to 1000VAC and 1500VDC maybe there are remnants of the high voltage heritage. If so, it certainly aligns with the defacto field electrical "rule of thumb" stated by Sandmantoy, HV, no solder; LV (<=24VDC), solder.

But in any case, I cannot source the complete VDE 0611 document without shelling out hundreds of bucks (which I'm not inclined to do given what I've recently spent on rocket motors), but I cannot find the parallel phraseology as quoted by John above in the IEC standards. The only reference made to soldering/tinning I can find in the IEC docs again relate back to screw terminals (see below). The only place I can find the specific quoted phrasing above is in connector/ferrule manufacturer's marketing documents.

IPC-A-620, 4.1 Wire Preparation, Tinning. "Note: Wires intended to be secured to threaded fasteners or crimp terminations shall never be tinned."

This specific statement above in IPC-A-620 is made for crimp terminations and threaded fasteners. Clearly you don't want to tin a wire before crimping as it will inhibit the crimping action. Threaded fasteners according to the same document (see picture excerpt attached) wrap around screw threads. Again, based on common sense you don't want to tin wires that have to then bend/wrap around a screw (too stiff/added stress). In our applications in rocketry, most often the connection is to a terminal block. Although the terminal block is operated by a screw, the actual connector mechanism is, in most cases, a sandwiching action.

 

[dixontj93060]

Unreliable contacts due to tinning is a mechanical engineering issue not electrical.

Well, not just mechanical, electro-mechanical and electrical. The parallel IEC document to VDE 0611 has a whole battery test specs related to electrical performance of the connector/terminal/crimp/etc. along with the mechanical tests (partial list attached).

Hmm.
Too bad most of US ERP systems are run by SAP (German)
Industrial controls Siemens (German)
Most popular industrial CAD system Solidworks (French!)

I could go on and on listing EU tech that has completely displaced US tech in EE and software. We're screwed.

I would be careful not to equate business success with technical prowess--they are miles apart. Seldom does the best/most advanced/novel product/idea win.

You mention Siemens... I used to work for a division of Siemens/Bosch in Germany. It was like pulling teeth for them to understand high level software concepts and complex electrical systems, in the end we had to build a "skunk works" team in the U.S. to get anything done. Granted, things have likely changed since then (circa 1990 or so), but one of the folks I used to work for (and good friend) advanced to the Board of Directors for Siemens--and up until his retirement I know he still struggled with these same issues.

Edit: Europeans also kick our professional golfer's butts.

AGREED!

View attachment IEC60947-1 and 2approved.pdf

 

[jderimig]

There may be some confusion as to applicability here. The original Low Voltage Directive started in Europe to define connectivity/safety applied to "all electrical equipment designed for use with a voltage rating of between 50 and 1000 V for alternating current and between 75 and 1500 V........

Ok ok, my Phoenix Connector (most ubiquitous connector used on rocket altimeters) still stands though...

https://phoenixcontact.custhelp.com...p_tbl=9&p_id=149&p_created=1246298765&p_olh=0

The biggest risk I personally have with tinned connectors is that the risk of fatigue breakage of the wire where the tin transitions to strands in the lead (away from the connection) is very high.

Anyone can do this test themselves, tin a lead and bend it back and forth and count how many cycles to break, do the same with an untinned lead.

 

[dixontj93060]

The biggest risk I personally have with tinned connectors is that the risk of fatigue breakage of the wire where the tin transitions to strands in the lead (away from the connection) is very high.

Anyone can do this test themselves, tin a lead and bend it back and forth and count how many cycles to break, do the same with an untinned lead.

Actually, I totally agree with this. If you have significant vibration or normal mechanical movement (even scheduled maintenance could apply in some cases) over an extended period of time, tinning is not the best choice (but then again, neither is solid wire in that application).

NICE CONNECTOR, BTW.

 

[sandmantoy]

I agree with solid wire not being a good choice and I guess there is no way to fool proof any system of attachment. I don't think we have problems with corrosion without compromising the altimeters also. I have seen some pretty nasty wiring done in electronics bays and do see your point about the wire braking. I think in those instances tinning the wire would be even more important to eliminate the chance of a stray strand being a liability.

I still think those rules are more about the voltage being a problem with tinning the wires. I think securing the wiring would eliminate most other problems one would encounter. I also think with our light duty application that most of this is not that big a deal when some are just twisting the arming wires together and taping them to the outside of the rocket anyway lol. :y:

 

[berlinetta]

Switches?:confused2: I don't use no switches! Twist and tape! It works, simple and efficient!

Twist the leads from the switch terminals together, tape, then listen to altimeter beeps and then tape to side of rocket..Or you COULD tuck it back through the vent hole into the avbay..But, taping to the side of the rocket makes disarming a lot easier if you have a misfire or ignition problem with the motor...:2:

Would you suggest the twist and tape method for flights breaking mach or could break mach. I am considering trying this method with my ARR Predator Jr.