Mechanical Mod Safety
Mechanical Mod Safety
Ok so we do get a lot of requests from people, that are new to mechanical mods, to sell them a Noisy Cricket or other hybrid mechanical mods. About 90% of these requests are usually denied due to the nature of this mod. The other 10% we do find are experienced users of RDAs and already capable coil builders.
For the 10% we do a general overview on usage, maintenance, and caring for the mod over time. The thing we focus most on is battery safety.
Now for the 90% that are very new to this we start off with coil building, RDAs etc. In-depth knowledge is passed on and about 50% of these customers generally admit to going blindly into these purchases and also admit they wanted it because the mod looked cool to them. Another scenario is where a friend bought one and they want one too.
Have a look at this brilliant video that Kent Hill at Twisted Messes posted about the Noisy Cricket
First things first.
What is a hybrid mechanical or hybrid mechanical series mod. Lets break down what that means.
Hybrid This means that the mod does not have a regular spring loaded 510 connector like what is found on regulated and some other mechanical mods. The benefit of hybrid connections is that atomizer makes direct contact with the battery. The advantage of this is that you get the most direct contact to the battery with zero voltage loss to the atomizer. In order for this to work you need an atomizer with an adjustable 510 connector or one where the positive pin protrudes past the threads of the connector. See the image below on what is safe.
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Mechanical (in this case) refers to the nature of the mod. It is unregulated and has no built in protection against shorting or low battery drain. Some mechanical mods like the KVLT for example has a built in mosfet to protect the switch mechanism.
Series refers to the configuration of the batteries. You get two types of configurations parallel and series. With series your batteries sit back to back doubling the voltage of the mod but keeping the amp draw limits equal to that of a single battery. In parallel the batteries sit side-by-side offering around a third more the amp draw limit but keeping the voltage equal to that of a single battery. When building for series we need to keep this in mind. Double voltage equals a lot more power. We will dig into this further down when we discuss ohms law, heat flux etc etc etc.
That explains the terminology of the mod itself.
Ohms law and all that science class stuff
Now lets go back to school quickly and discuss ohms law and how to easily calculate your amp draw that the build will handle.
The potential difference (voltage) across an ideal conductor is proportional to the current through it. The constant of proportionality is called the resistance, R. Ohms Law is given by: V = I R where V is the potential difference between two points which include a resistance R.
That part makes zero sense to me so lets simplify it and use the formula in a practical example to show how it works.
Lets start with a fresh set of 18650 batteries. Im going to use the Samsung 25R as an example. They are a solid 2500mAh battery with an amp limit of 20A (continuous draw). Two of these in series will happily have 8.4v available for use. This 8.4v however will not go straight to the coils due to voltage sag created by the build. Keep in mind that you still only have 20A available. This 20A is continuous so you are looking at 35A 50A pulse, depending on the build. Im using continuous drain rate instead of pulse rates. While the continuous rate is when holding the button down until the batteries are completely drained I do feel that the continuous limit is safer to work with for inexperienced users.
To easily work out how many amps a build will draw we take the available voltage and divide the builds voltage into it. Lets work with a 0.5ohm build to be safe.
8.4v / 0.5ohm = 16.8A. Perfectly safe for the batteries.
Now you must be wondering what the wattage is going to be. Simple. Take the amps and multiply by your voltage.
16.8A X 8.4v = 141,12W
This is the most basic way to calculate it. When we discuss the coil builds to use you will understand why 140w isnt necessarily too much for this.
The above calculation is completely theoretical as in real world scenarios the build will cause voltage sag so the overall result will be lower.
Lets dive into how building coils work and how to build something usable for this mod.
First thing to understand is heat flux. Heat flux is the rate of heat transfer through any given surface. In particular with vaping and coils we are looking at heat flux density which is measured in W/m² or mW/mm² (milliwatt per square millimeter).
The easy way to explain is by using the example of taking 1 litre of water and filling two different objects with it.
Lets fill a glass with it. It basically overflows and makes a mess.
Now fill a swimming pool with it. It hardly wets the bottom of the pool.
Now look at two different coils and 8.4v of power being fed into them. A 28ga kanthal coil at 0.5ohm and a 22ga kanthal coil at 0.5ohm. Due to the nature of the wire they will have a different resistance. So to get both to 0.5ohm we have to take a certain length of wire and make a coil. 28ga will be 28mm of wire. 22ga will be 113mm. Now lets see what the heat flux of each will be.
28ga 4970 mW/mm²
22ga 617 mW/mm²
The 28ga is basically melting as soon as the power hits it. The 22ga will get hot but not instantly melt.
The key thing to know with this is that you need to the right size (not resistance) of coil. Since we have a fixed voltage and wattage with the build we need to find a balance between power and mass of metal being heated up.
My go to build on the cricket is a single coil 22ga at 3mm ID and around 14 wraps using Anarchist AN80 NiChrome wire. This is a great vape for me. Not too hot and the flavour and vapor production is spot on.
Kanthal was used in the calculations above. NiCr80 has a lower resistance so you need more wraps to get to the target resistance. However this yields lower heat flux since you have more metal to heat up.
Keeping the coils in check
We have two elements that basically cool these monsters down. The juice and airflow. As long as you have air and juice on the metal things will stay nice and comfortably in control.
Now you may ask, how do I get a cooler vape. Two ways to do it. Add more air or lower the heatflux. Basically you adjust your build so the device puts out less power or you add more metal to heat so that the heat is reduced.
The best batteries to use in mechanical mods are the ones with the highest possible discharge rate. Not the pulse, but rather the continuous rating.
When you just get the mechanical mod of your dreams you might be tempted to keep using it for as long as possible. The problem here is that you might actually run into a scenario where you accidentally drain the batteries too low. It happens easier than you think.
My advice is to check the voltage of both cells individually after every hour of use. Dont let them drain below 3.6v to be safe. After a while you will start to develop a sense for when the mod isnt hitting as hard as it does on fresh batteries. Make sure to use a proper battery charger.
It is normal for the mod itself to get warm when using it. Especially with big builds. This is mostly due to heat soak from the atomizer into the mod. It should however not get HOT! If it does get hot in your hand i suggest you put it down in a safe spot and let it sit to cool down.
The noisy cricket as well as most other mechanical mods are equipped with adequate vent holes at the base of the mod. This is to assist with cooling and to protect against catastrophic failure in the event of a battery venting on you.
Due to the mod being assembled and disassembled quite often to install batteries I suggest cleaning the threads with a microfibre cloth and rubbing alcohol every time you take it apart. This makes it easier to keep it operating at maximum efficiency and prevents layers of gunk building up on the threads over time.
With the cricket we have noticed some aluminium corrosion, a fairly common but potentially big issue. Also we have noticed some heat build-up in the switch that can burn your finger when pulsing if it touches the gold part.
Always make sure you attach the atomizer to the positive side of the battery and the fire button to the negative. Getting these two mixed up can cause the mod to auto fire. This is due to the protruding positive on some batteries making contact with the fire button. Weve seen this happen. Scary!
When not in use either remove the batteries or unscrew the fire button. double check that it cant fire.
Dont leave the device in the car or in any situation where it can get hot.
Make sure that the atomizer has the correct 510 connection.
Builds, builds, builds. No what works and what doesnt
Keep those batteries charged.
Please feel free to contact us at any time if you have any questions or if you are unsure about anything with regards to safety on mechanical mods.