Causes of Short Circuits: All Equally Dangerous?

[DarrellG]

Based on everything I've read I have a feeling that the answer is yes, but not being 100% sure...

If a short were caused from an AFC contacting the coil, would we expect the potential results to be as bad as a short caused from an ill-conditioned wrap in the tube, a coil touching the post, or the negative threading of a pin contacting the battery in a direct battery connection? Did I leave any out?

I just got my first single 18650 mech a couple days ago: vgod. I'm trying to clear up some uncertainties before I try it out. I understand ohm's law. I know how to keep batteries in proper condition and which type to use for the range I'm building at (got some HB4's and VTC5A's). I'm not building super low; planning on around .2 to get a feel for things. I'm using the BMI Goldie (pin protrudes nicely). I'm just not satisfied enough with my understanding of shorts to fire the thing up yet.

Any input appreciated. Thanks.

 

[Ben85]

My advice would be to avoid any kind of short. If you know what you are doing then this is not a difficult task. No short is "better than" another - just build safely and use good batteries.

 

[DarrellG]

My advice would be to avoid any kind of short. If you know what you are doing then this is not a difficult task. No short is "better than" another - just build safely and use good batteries.

Yeah, I understood that regardless of the answer the bottom line would be to avoid any type of short.

Honestly, and oddly enough, the AFC/barrel of the atty is what I'm most concerned about. I feel like I have a handle on everything else. So many images I've seen of mech builds look like they have just a sliver of space between the coil and the AFC, to me they look pretty scary. Those images are really what prompted the original question, making me question if that type of short was of less concern for some reason. Do you tend to build coils that are close to the edge, feeling confident that they won't shift at all, or is it best practice to build as small as possible and have a good amount of space?

Thanks for the reply.

 

[Ben85]

Yeah, I understood that regardless of the answer the bottom line would be to avoid any type of short.

Honestly, and oddly enough, the AFC/barrel of the atty is what I'm most concerned about. I feel like I have a handle on everything else. So many images I've seen of mech builds look like they have just a sliver of space between the coil and the AFC, to me they look pretty scary. Do you tend to build coils that are close to the edge, feeling confident that they won't shift at all, or is it best practice to build as small as possible and have a good amount of space?

I build mine as close to the posts as possible, put on the AFC ring/ barrel and then visually check that it is not touching by looking from above. I also check the resistance when it is fully assembled to double check for any shorts.

 

[Ben85]

Another point to add, I am confident that they won't shift, but if I dropped it I'd be sticking it on a meter again and checking for shorts again before use.

 

[DarrellG]

Thanks a bunch for the input, Ben. Much appreciated.

 

[distortoblotto]

Never use a build without reading it on a meter. Equally important...Always make sure your build and battery can handle your amp draw.

 

[Kprthevapr]

Some people build really close to the center posts, while others build closer to the air flow. It all depends on personal preference.

With my stumpy, I build as close to air flow as possible, so I don't get hot juice spitting in my mouth. You can check to see if will touch/too close to the top/sides by resting the top cap on the coils.

 

[DarrellG]

Some people build really close to the center posts, while others build closer to the air flow. It all depends on personal preference.

With my stumpy, I build as close to air flow as possible, so I don't get hot juice spitting in my mouth. You can check to see if will touch/too close to the top/sides by resting the top cap on the coils.
View attachment 627111

Thanks for the tips and image, man.
I guess I just have a touch more anxiety when it comes to this specific issue; maybe more than is called for, but it's comforting to get this feedback from experienced users. I think I just need to get accustomed to building and testing the builds with more patience and attention to detail. Being anxious by nature, I might need to pop some 40mm monstrosity on my tube to feel completely at ease. That would be a sight.

 

[Ben85]

It's good that you are questioning it. Better that than just winging it and hoping for the best.

I always think that if I am concerned that the coil will touch either the AFC or the centre posts, I am probably trying to fit too large a coil in there in the first place. I'd just then reduce the diameter of the coil on the next build.

 

[DarrellG]

It's good that you are questioning it. Better that than just winging it and hoping for the best.

I always think that if I am concerned that the coil will touch either the AFC or the centre posts, I am probably trying to fit too large a coil in there in the first place. I'd just then reduce the diameter of the coil on the next build.

Right on. And no chances of winging it here. I'm in no rush.

 

[Ben85]

You do realise we will need some pics of your set up right... We like a good pic

 

[Kprthevapr]

You do realise we will need some pics of your set up right... We like a good pic

This is true

 

[DarrellG]

You do realise we will need some pics of your set up right... We like a good pic

I can't promise anything pretty, but when I get it set up I'll be sure to share.

 

[Ben85]

Hey, a pic's still a pic. You should see some of the cack photo's I have posted up

Good luck with your mod. Mech mods are what "made" vaping for me.

 

[Kprthevapr]

Hey, a pic's still a pic. You should see some of the cack photo's I have posted up

Good luck with your mod. Mech mods are what "made" vaping for me.

There are very few of us mech mod users still around, so any chance to get a pic of someone else's mod is fun for us "ole timers"

 

[Verb]

The topcap shorting a coil is not nearly as bad as a torn wrapper short or compressible center pin atty on a 510-hybrid. There is a bit more resistance with the topcap-coil short and it will most likely melt the resistance wire breaking the circuit before thermal runaway.

 

[mongo74]

I have the same mech, and a dead short caused by a 510 that's pushed in (or had the insulator melted off causing contact of the negative outer ring of the atomizer with the positive terminal of the cell) is the worst case scenario, other than putting the battery in upside down. While using a battery with a torn wrap is a huge no no with mechs, the delrin lining insde the Vgod is a last line of defense against a wrap with an unnoticed miniscule tear.

Bear in mind, even if you're an expert builder, you MUST ALWAYS use a meter or regulated mod to check your build and make sure there are no shorts (ie: coil touching posts or sleeve of atomizer) If you build to close to the sleeve of the RDA/RDTA, you run the risk of the coil literally arcing off the sleeve and burning it, and that can get ugly really quickly.

Play it safe, don't rush, triple check everything and enjoy that instantaneous hard hit a hybrid can deliver.

 

[DarrellG]

More great stuff. Appreciate all this info, guys.

@mongo74 The delrin lining was the key selling point for me. Simple enough to give the wrap a good looking over, but I figured another layer of protection certainly can't hurt. This is the first I've heard of arcing. I get that building safe can easily avoid these hazards, but just for the sake of curiosity, are we talking about the potential for an arc across a distance of, say 1mm, or more like a distance where it practically looks like the coil is making contact?

Apologies if this is getting too pedantic, but if this info is out there I'm all ears.

 

[Kprthevapr]

Do you see the rim inside the atty? That's where the top cap/air flow control sits. As long as you don't build too close to the inside rim, you should be fine