RDA and Mech Mod Intro

[speedfreek67]

Safety:

Use ohms law to find the MINIMUM resistance, and *never* go below that.

For a given resistance of coil a dual coil RDA will have half the final resistance of a single coil. So take your target resistance and build two coils with double that resistance.

Use 4.2 volts as your input for safety (with a fully charged battery the amp draw will be at its highest).

Leave a margin (for safety and for errors in your resistance measurement) i.e. if your battery CDR is 35 amps keep the amp draw below 30 amps for example.

Scrupulously check your battery wraps. The tiniest little tear can cause a short circuit which could overload your battery and cause it to vent or explode.

Make sure your build is safe by checking the built RDA on an ohms reader or regulated mod. If there is a short circuit (possibly caused by an off cut of wire lying in the base of the RDA or your coil touching the top cap when you put it on, for instance, i.e. something touching somewhere it shouldn't), on an ohms reader or reg mod it will say "atomiser short" or similar and won't fire, but on a mech it will try to fire and short circuit the battery, causing damage to the battery and possible explosion.

Keep all threaded parts of your mech (and the threads on the 510 pin of your RDA) clean.

Periodically check for damage to insulators.

-_-_-_-_-_-_-_-_-_-_-_-_-_-

Comfort & Learning:

The lower the amp draw (the higher the resistance), the less stress you put on the battery and the longer the run time between battery changes. You can get a good vape at 0.5 ohms, for instance, using the right wire.

Different RDAs will produce a hotter or cooler vape using the same coils, as the space within the deck and the airflow are also factors.

Start off using simple wire, as it is easier to calculate. Nichrome flatwire is good in mechs. 24 gauge NI80 (nichrome) 3mm inner diameter, 6 wraps, dual coil, comes out at around 0.23 ohms.

Use http://www.steam-engine.org/ohm.html to calculate your safe build for your battery using 4.2 volts.

Use http://www.steam-engine.org/coil.html to see how different materials, coil diameter, number of wraps etc affect the heat output of the final build, at a given voltage (use 3.9 - 3.7 volts for this!).

Ask as many questions as you like.

Good luck!

 

[ChrisMcrUK]

Safety:

Use ohms law to find the MINIMUM resistance, and *never* go below that.

For a given resistance of coil a dual coil RDA will have half the final resistance of a single coil. So take your target resistance and build two coils with double that resistance.

Use 4.2 volts as your input for safety (with a fully charged battery the amp draw will be at its highest).

Leave a margin (for safety and for errors in your resistance measurement) i.e. if your battery CDR is 35 amps keep the amp draw below 30 amps for example.

Scrupulously check your battery wraps. The tiniest little tear can cause a short circuit which could overload your battery and cause it to vent or explode.

Make sure your build is safe by checking the built RDA on an ohms reader or regulated mod. If there is a short circuit (possibly caused by an off cut of wire lying in the base of the RDA or your coil touching the top cap when you put it on, for instance, i.e. something touching somewhere it shouldn't), on an ohms reader or reg mod it will say "atomiser short" or similar and won't fire, but on a mech it will try to fire and short circuit the battery, causing damage to the battery and possible explosion.

Keep all threaded parts of your mech (and the threads on the 510 pin of your RDA) clean.

Periodically check for damage to insulators.

-_-_-_-_-_-_-_-_-_-_-_-_-_-

Comfort & Learning:

The lower the amp draw (the higher the resistance), the less stress you put on the battery and the longer the run time between battery changes. You can get a good vape at 0.5 ohms, for instance, using the right wire.

Different RDAs will produce a hotter or cooler vape using the same coils, as the space within the deck and the airflow are also factors.

Start off using simple wire, as it is easier to calculate. Nichrome flatwire is good in mechs. 24 gauge NI80 (nichrome) 3mm inner diameter, 6 wraps, dual coil, comes out at around 0.23 ohms.

Use http://www.steam-engine.org/ohm.html to calculate your safe build for your battery using 4.2 volts.

Use http://www.steam-engine.org/coil.html to see how different materials, coil diameter, number of wraps etc affect the heat output of the final build, at a given voltage (use 3.9 - 3.7 volts for this!).

Ask as many questions as you like.

Good luck!

Ok so the battery I'm going to be using is a Samsung 30T. Nominal voltage is 3.6 and the max discharge current is 35. So resistance will be 3.6/35 = 0.10. So never go below 0.10? How high can I go?

What does it mean when you say amp draw?

This is the cotton I've ordered: https://masquevapor.com/gb/accessories/8831-wicker-beast-vape-cotton.html#
And these are the coils I've ordered: https://masquevapor.com/gb/demon-killer-coils/17915-parallel-double-015ohm-pack-demon-killer.html

 

[ChrisMcrUK]

main thing to remember with a mech is if it dont work pressing the button harder is not the best idea
if it gets rather hot v quick part ways
all ways test your build on a regulated mod/coil building thingamajig so you know its not shorted and around the right resistance
use the button lock as pocket firing is rather common
if your batts will take a 0.12 ohm build its not necessary to build all the way down to it leave a little headroom if you can
when your using it do take the cap off the rda once in a blue moon to check it all looks good in there

as for coils you can get funky wire now so its easier to build silly cloud chucking coils
fused clapton and flatron are my faves from crazy wire
if your buying prebuilt coils you need to aim for 0.3 ohm and above as when you put 2 coils in the ohms half so 2 x 0.3 will give an rda a 0.15 ohm resistance
hope that helps

Ok thanks. These are the cotton and coils that I've ordered:

This is the cotton I've ordered: https://masquevapor.com/gb/accessories/8831-wicker-beast-vape-cotton.html#
And these are the coils I've ordered: https://masquevapor.com/gb/demon-killer-coils/17915-parallel-double-015ohm-pack-demon-killer.html

 

[ChrisMcrUK]

If I can quote some tubby at you...

What does amp draw mean?

 

[decoy]

Ok thanks. These are the cotton and coils that I've ordered:

This is the cotton I've ordered: https://masquevapor.com/gb/accessories/8831-wicker-beast-vape-cotton.html#
And these are the coils I've ordered: https://masquevapor.com/gb/demon-killer-coils/17915-parallel-double-015ohm-pack-demon-killer.html

the coils will be to low for your batt if you use both ie it will come out at 0.075 ohms if you use both coils
https://masquevapor.com/gb/1412-demon-killer-coils
would be somewhat safer as you'll be at 0.15 ohms

 

[decoy]

What does amp draw mean?

draw is how much power your pulling from the batt
you are probably better off looking for coils that are 0.4 and above as this will let your batt last longer
its not all about going low ohms its a balancing act

 

[oldhippydude]

Ok so the battery I'm going to be using is a Samsung 30T. Nominal voltage is 3.6 and the max discharge current is 35. So resistance will be 3.6/35 = 0.10. So never go below 0.10? How high can I go?

What does it mean when you say amp draw?

This is the cotton I've ordered: https://masquevapor.com/gb/accessories/8831-wicker-beast-vape-cotton.html#
And these are the coils I've ordered: https://masquevapor.com/gb/demon-killer-coils/17915-parallel-double-015ohm-pack-demon-killer.html

No.
The max voltage on the battery fuly charged is 4.2 volts as @speedfreek67 points out in his post.
Use 4.2v in your calculations

 

[speedfreek67]

Ok so the battery I'm going to be using is a Samsung 30T. Nominal voltage is 3.6 and the max discharge current is 35. So resistance will be 3.6/35 = 0.10. So never go below 0.10? How high can I go?

No, you do not use the nominal voltage, you use the fully charged voltage of 4.2 volts. You have already been told this twice, and acknowledged this earlier. Sorry if I sound harsh, but with a mech YOU are the only safety measure, so you *have* to understand exactly what you are doing and you *have* to concentrate, as slipups could be very dangerous.

4.2/35 = 0.12 and at these low resistances, which are almost hard shorts, 0.01 of an ohm can make a big difference to the amps drawn from your battery.

You can go as high as you like, 0.2, 0.4, 0.6 ... 1.8 etc, but no lower than 0.12. The higher the resistance, the lower the amp draw. The lower the resistance, the higher the amp draw.

What does it mean when you say amp draw?

The amps drawn from your battery, which is dependent on the resistance of your build. Too low a build will draw too many amps and cause your battery to overheat, damaging the battery and possibly causing it to vent or explode, turning your RDA/mech setup into a pipe-bomb.

This is the cotton I've ordered: https://masquevapor.com/gb/accessories/8831-wicker-beast-vape-cotton.html#
And these are the coils I've ordered: https://masquevapor.com/gb/demon-killer-coils/17915-parallel-double-015ohm-pack-demon-killer.html

Cotton is a personal choice, but you need to make sure your coils are at least 0.24 ohms each, as when you use two of them the result is halved and needs to be 0.12 or above.

I can't tell from that webpage whether the coils are 0.15 ohms each (too low) or 0.3 ohms each resulting in 0.15 ohms for the pair.

If you want to try them, install one of them only and check the resistance on a regulated mod. You will probably want to look at YouTube tutorials on how to install coils, bedding them in and making sure they glow evenly from the inside out. You need to "fettle" a coil when you install it, to make sure it is bedded in properly and reading it's resistance consistently and you will need ceramic tweezers to do this properly, along with sidecutters (snips) to cut off the extra wire.

If one coil is reading 0.3 ohms or thereabouts after installation, then you can install the second one to bring the build down to around 0.15 ohms.

If one coil is reading 0.15 ohms then the coils are of too low a resistance for dual coiling.

To be honest, most people would recommend starting out on a single coil RDA and getting used to building using a regulated mod before venturing into dual coils or mechanical mods.

 

[ChrisMcrUK]

draw is how much power your pulling from the batt
you are probably better off looking for coils that are 0.4 and above as this will let your batt last longer
its not all about going low ohms its a balancing act

Thanks for your help.

So I should be ok with these? https://www.cloudzvapour.com/product/fused-clapton-pre-made-coils-0-45ohm/

When using RDA's how often do you drip liquid on to the coils? Is it the same as sub ohm tanks, i.e. when the flavour goes or you get a burnt taste?

 

[ChrisMcrUK]

draw is how much power your pulling from the batt
you are probably better off looking for coils that are 0.4 and above as this will let your batt last longer
its not all about going low ohms its a balancing act

Oh and can I just use the same liquids I’ve been using in my sub ohm tanks or do I need to be getting something different.

Sorry again for all the questions