Mech queries (advanced)

Scissorhands

Scissorhands

Dedicated Vaper
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Good day ladies and gents!

This is a space for mech user's to question/discuss/answer anything mech related, from basic maintenance, pro tips to personal experiences, anything goes

I would like this thread to be more technical/educational as opposed to product/clone related if possible

Ill kick this off with 2 questions

1) Would i be correct to assume that a mods volt drop is due to the mods own resistance in the circuit

eg. If i know a mod is putting out 3.7v on a fresh battery (4.2v) with a 0.2 ohm coil, i will in fact pull a max 18.5 amps, not 21 amps . The mod will have a resistance of roughly 0.027 ohms (please correct me if my understanding is flawed)

2) what product/s do you use on your aluminium,gold, brass and copper contacts to avoid arching/pitting/carbon build up

I hope that made sense
Best regards
 
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First of all, I think its necessary to define what a mech mod actually is. I see way too many people referring to their Noisy V2 Mech or Tesla Invader Mech.

A mechanical mod has absolutely no circuitry. As in Nada. no protection, no control, nothing. These devices generally cleverly break (and close) the circuit by means of a switchable contact plate between the negative of the battery and chassis of the device. In saying that, the chassis forms the ground/negative portion of the circuit (in laymens terms), and the positive is delivered straight to the 510 pin of your atty (either direct AKA hybrid, or an intermediary pin between the battery and 510 pin on your atomiser. Voltage/Power/Current is controlled by ohms law (the coil build in your atomiser).

Once you start finding electronic components between your batteries, chassis and 510 connector, you are treading into the "Unregulated" or "Regulated" world. This is beyond the scope of this thread so I will defer from explaining this further.

My attempt to answer your questions @Scissorhands :

1. Voltage drop in a mech is due to amount of material used. Simplify this a bit... consider using 2 PVC pipes, both connected to identical water taps, but the one is 1 meter long and the other is 10 meters long... you open the taps at the same time, which pipe does the water come out first?

2. I generally stick to copper, for conductivity, durability and affordability. To keep clean, I use a fine grit sandpaper or a blade and gently scrape off any build up. I know that there are probably better methods, but this works for me.
 
GREAT IDEA FOR A TREAD!Love it. my answers here would be as follows.

Regarding voltage drop, the general consensus of my research points to this.
The resistance of a tube mech, made of copper, is generally so low, it's almost nothing. The issue, is the internal resistance of the battery.

And secondly, I found to keep contacts clean, an eraser works great, but to really clean it, a blade to scrape off build up, and the the old vinegar & hot water bath.


Sent from my iPhone 7+ using Tapatalk
 
Thanks for your response @Cespian , I agree with your definition, and yes vendors market unregulated devices as mechs . . . Wich is misleading

1) i understand your analogy in terms of "a shorter path will generate less resistance" but more material could aid in conductivity between point A and B if the distance between A and b remain the same (eg. 20awg vs 32awg)

But still believe other factors are larger contributers like the surface area between contact poins in the switch/button as this would be a choke point

(Please know that none of this is fact, just my understanding, wich i hope someone would improve/correct, to better my understanding)

Regards
 
I clean my contact with a white eraser, followed by an alcohol pad. Thereafter some Deoxit Gold gets applied. If the eraser and alcohol do not get it clean, I use those 4 step nail buffers, followed by alcohol pad and Deoxit Gold.

9b285844-c5c5-5d40-0844-e92c54bf4013.jpg
 
Thanks @Andre ! Thats the answer i was looking for, i assume deoxit gold would be something to look for in electronic/repair places?

@GerritVisagie i enjoy the presence and enthusiasm in your posts, glad to see you here
 
I'm relatively new to Mech Mods, being an electrician I understand the ins and outs, possibly what made me love them more than regulated mods. If possible could you guys add pics of your setups, Clone/Authentic and HE/LE it doesn't matter. Looking at getting myself a decent mod, something solid. Would like some of your opinions.

That aside, for cleaning and polishing purposes I've ordered myself https://m.fasttech.com/p/7462700 will review it once I receive it.

Material wise I'm not fond of the copper odour so I will always choose SS over copper.
 


It's quite long and not in HD but a cool real world experiment. On the copper vs brass and SS mod material. Does volt drop and power readings.
 
Scissorhands said:
Thanks @Andre ! Thats the answer i was looking for, i assume deoxit gold would be something to look for in electronic/repair places?

@GerritVisagie i enjoy the presence and enthusiasm in your posts, glad to see you here
Click to expand...
Not sure if Deoxit Gold is available locally (mine was imported via the good graces of @Rob Fisher), but I am sure those shops should be able to point you to suitable alternatives. I know in the Reoville forum they mentioned some, but cannot remember the names.
 
CeeJay said:
I'm relatively new to Mech Mods, being an electrician I understand the ins and outs, possibly what made me love them more than regulated mods. If possible could you guys add pics of your setups, Clone/Authentic and HE/LE it doesn't matter. Looking at getting myself a decent mod, something solid. Would like some of your opinions.

That aside, for cleaning and polishing purposes I've ordered myself https://m.fasttech.com/p/7462700 will review it once I receive it.

Material wise I'm not fond of the copper odour so I will always choose SS over copper.
Click to expand...

Im also not too fond of copper, living on a coast line (salty humid air & sweaty hands) doesn't help

As requested , i know, terrible lighting

20170628_172247.jpg

And as i mentioned in the OP i dont want this thread to be centered around products but i make a terrible policeman and i do like eye candy :)
 
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Hey guys.

Regarding the whole voltage drop debate (in tube mechs that is), the material used in the tube of a mech doesn't matter at all to be honest. Where voltage drop plays the biggest role is in die button and threads of your mech. For example, let's say you have a mech which has a removeable button and 4 tubes which are all similiar but one which is SS, Ti, Copper and Brass. If all of them are identical in wall width and length overall each one would hit as hard as the next with a tiny bit more voltage drop on the SS tube, but not really enough to notice. Mooch did a very detailed bit on this subject and I have found it to be true. I always thought that I would only use copper mechs as they are the hardest hitters right? Except for a full silver mech. Yet I have used mechs now which have been all different metals and the ones that have hit the hardest are ones with proper copper buttons or brass buttons with copper pins, regardless of the tube material. I have a full brass able with a copper pin and brass button which hits extremely hard, yet a friend of mine has a titanium comp lyfe predator with a brass button which hits harder even though it is made of titanium which is less conductive. Reason being the quality of the button and thickness of the walls of the tube. Thus eliminating the need for a messy and extremely fast tarnishing copper tube. Hope that adds some insight to common beliefs centred around mechs..
 
Re voltage drop. If the voltage drops between the battery and my coil, what is being drained from my battery? The 4.2v of the battery or the 4.0v that's reaching the coil (hypothetical numbers)?

If it's the 4.0v that's reaching the coil, would it also apply to the amps the battery is putting out? The formula says yes, but I ask stupid questions.
 
spiv said:
Re voltage drop. If the voltage drops between the battery and my coil, what is being drained from my battery? The 4.2v of the battery or the 4.0v that's reaching the coil (hypothetical numbers)?

If it's the 4.0v that's reaching the coil, would it also apply to the amps the battery is putting out? The formula says yes, but I ask stupid questions.
Click to expand...

Actually the 4.2v, but there are other factors to consider. Keep in mind that the complete circuit is made up of the battery and all of the parts that make up the load circuit. If there is a voltage drop, it is due to resistance in components between the battery and the coil - battery contacts, springs, connector pins, switches etc. They all form part of the total series circuit that 'loads' the battery.
The actual load on the battery will depend on the overall resistance of your coil AND all of the components. If your coil is 0.25 ohm and all the components together adds up to another 0.01 ohms, the circuit will thus only deliver as if the coil is a 0.26 ohm build on a 4.2v battery. This is using your hypothetical values of 4.2v and 4.0v.
So, instead of a 70.56 Watt vape, you will effectively vape a 67.85 Watt build and the current draw would be 16.15A instead of 16.8A.

You can use a voltage divider calculator such as http://www.calculatoredge.com/electronics/voltage divide.htm and plug in our known values of Vin = 4.2v, Vout across the coil = 4.0v and the Coil itself is Rb @ 0.25 ohm. Ra calculated would then be the 0.01 ohm that is the sum of the rest of the 'whacky' mech and atty parts that refuse to play ball.

A hefty perceived voltage drop could also be due to ageing batteries and a sag in voltage due to higher internal resistance when the load increases - e.g. they might measure around 4.2v fresh off a charger, but as soon as they are loaded, the output actually drops to 4.0v ( also a hypothetical example )
 
Hi @Scissorhands , great thread

I will also try answer your questions and add some further comments:

Regarding volt drop, the way I understand it is along the lines of what @Kuhlkatz so greatly explained above. Its not just the resistance of the mod itself but also the internal resistance of the battery AND the coil you put in. A much lower resistance coil will lead to a higher measured voltage drop under load at the posts than a higher resistance coil, all else being equal.

I tested the volt drop of my Reos a while back under load and found that the volt drop tends to be around 0.2V with a 1 ohm coil. I.e. If the battery voltage was 4.1V, then the voltage at the posts while pressing the fire button was 3.9V. Not easy to do it with two hands because the probes need to be firm on the posts and then you need to fire it ;-)

As for your second question about something to help with arcing and pitting, i am using dielectric grease. @Alex got it for us at a supplier somewhere in the East Rand I think. He got a whole tub/can of it. He thrn gave me a large syringe full about 2 years ago and i have only used about 1/10th of the syringe! I put a tiny tiny amount of it on the battery positive terminal and spread it out with the sharp point of a toothpick. And i do the same on the positive pin that makes contact with the battery. It stays on there for a long time, only needs more once in a while.

From time to time I also do what @Andre recommended above, using a white rubber eraser and also wipe with rubbing alcohol.

I havent had any problems with major pitting (at least not that I can see with the naked eye) and my Reos are still firing very nicely 3 years on, so they must still be ok. But then again, i dont go very low on the resistance so am not overly stressing things. My lowest usable build on my Reos is about 0.4 to 0.5 ohms. So thats drawing only about 8-10 amps.
 
Kuhlkatz said:
Actually the 4.2v, but there are other factors to consider. Keep in mind that the complete circuit is made up of the battery and all of the parts that make up the load circuit. If there is a voltage drop, it is due to resistance in components between the battery and the coil - battery contacts, springs, connector pins, switches etc. They all form part of the total series circuit that 'loads' the battery.
The actual load on the battery will depend on the overall resistance of your coil AND all of the components. If your coil is 0.25 ohm and all the components together adds up to another 0.01 ohms, the circuit will thus only deliver as if the coil is a 0.26 ohm build on a 4.2v battery. This is using your hypothetical values of 4.2v and 4.0v.
So, instead of a 70.56 Watt vape, you will effectively vape a 67.85 Watt build and the current draw would be 16.15A instead of 16.8A.

You can use a voltage divider calculator such as http://www.calculatoredge.com/electronics/voltage divide.htm and plug in our known values of Vin = 4.2v, Vout across the coil = 4.0v and the Coil itself is Rb @ 0.25 ohm. Ra calculated would then be the 0.01 ohm that is the sum of the rest of the 'whacky' mech and atty parts that refuse to play ball.

A hefty perceived voltage drop could also be due to ageing batteries and a sag in voltage due to higher internal resistance when the load increases - e.g. they might measure around 4.2v fresh off a charger, but as soon as they are loaded, the output actually drops to 4.0v ( also a hypothetical example )
Click to expand...

Thanks! This makes so much sense.
 
I have a Karma Mech Tube with Sony VT5 and placed 2 stapled coils in as below

It is coming out at .19ohm and not firing......should it fire?

upload_2017-7-12_12-36-20.png
 
stephen.johnson2 said:
I have a Karma Mech Tube with Sony VT5 and placed 2 stapled coils in as below

It is coming out at .19ohm and not firing......should it fire?

View attachment 100971
Click to expand...
A VTC5 is rated at 20 amp continuous, assuming you are getting 3.7V you will be drawing 19.4 amps, personally that is a little close for my comfort.

But to answer your question, a mech should fire anything you throw at it, there's no safety

Are you using the Karma RDTA?
 
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