Versed Vaper
Wotofo Cog MTL RTA Review Main Banner
Home » Reviews » Wotofo Cog MTL RTA Review: Gear Mechanism Airflow

Wotofo Cog MTL RTA Review: Gear Mechanism Airflow

Wotofo Cog MTL RTA



Wotofo Cog MTL RTA 1
Design — 8.0
Build Quality — 9.0
Ease of Building — 9.0
Performance — 7.0
Flavor — 9.0



Check Price

Wotofo has teamed up with Matt from SMM to bring us the Cog MTL RTA. It is a mouth-to-lung RTA designed especially for builders who prefer nic salts or high nicotine vaping. It features a single coil setup on a 22mm build deck and a 3ml tank reservoir (2ml TPD version).

The Cog MTL RTA has an innovative gear mechanism, which Wotofo claims offers very precise air flow tuning. 

Does the Wotofo Cog redefine MTL vaping with its gear mechanism airflow control?

This tank was sent to me by Wotofo for the purpose of this review.

Box ContentsWotofo Cog MTL RTA Box Contents

  • 1 x Wotofo Cog MTL RTA
  • 1 x 510 Delrin drip tip
  • 1 x Fused Clapton coil 0.8 ohm
  • 1 x Single Strand coil 1.2 ohm
  • 1 x Bag of 2.5mm cotton strips
  • 1 x Bag of Spare o-rings and screws
  • 1 x Cross head screwdriver
  • 1 x User manual


  • 22mm Base Diameter
  • PCTG (plastic) Tank
  • MTL Draw
  • Unique Airflow Mechanism
  • Single Coil RTA
  • 3ml Tank Capacity (2ml TPD version)

Design & Build QualityWotofo Cog MTL RTA 1

The first thing I noticed when unboxing the Cog MTL RTA is how good it looks. I received the stainless steel version for review, you can also get it in black, gunmetal, blue, gold and rainbow. The colour you choose will be the colour of the base, inner cover and metal inside the top cap. The tank itself is made from PCTG, which is a plastic, and it’s hard to put into words how shiny it is compared with glass. It suits the stainless steel of the rest of the tank perfectly and doesn’t attract fingerprints or smudges the same way glass does.

The Cog MTL RTA comes with a 510 delrin drip tip that is designed to condense the vapour and give a mouth to lung draw. I’m not really a mouth to lung vaper, but quickly became used to the drip tip and found it to be very comfortable to use, not becoming hot when vaping for extended periods of time.

The top cap of the Cog MTL RTA unscrews to allow you to fill the tank. The top cap is the same stainless steel on the inside, but covered in the PCTG material of the tank itself. This means when the top cap is screwed on it blends in with the whole tank, creating a really nice, uniform look. Under the top cap, on the top of the tank, you will see two kidney shaped filling ports for putting in your juice. These are adequately sized, to allow you to fill up the tank without spilling liquid everywhere.

As mentioned above, the tank is made of PCTG, not glass. It looks good, and is really light weight compared with glass. I did have initial concerns over the durability of the material, but over my two weeks of testing I haven’t encountered any issues with durability. One thing the light weight will allow is the ability to use the tank on smaller mods, without it being top heavy. With the small diameter of 22mm and a height of 51mm, if the tank was made from heavier glass and sitting on a small mod, I could see it being unstable if you knocked your setup while it was sitting on a table, for example. So the lightweight of PCTG definitely has its merits. 

On the bottom of the base of the tank there is a gold plated 510 connector pin. However, instead of your usual regulation marks etched onto the metal base, there is a clear window, allowing you to see the cog mechanism that the tank gets its name from.

Overall, I love the design of the tank. It looks good, with the PCTG material really complimenting the stainless steel of the rest of the tank. It has a transparency to it that you don’t seem to get from glass and it looks good all the time, no fingerprints or smudging on the tank. Also light just seems to pass through it better than glass, reflecting off the inner chamber.


  • Wotofo Cog Gear Mechanism Airflow

The airflow system on the Cog MTL RTA is what it’s all about. The base of the tank has two airflow slots, one on either side. But, instead of adjusting the airflow with an airflow control ring that covers or reveals more of the slots, Wotofo and Matt, from SMM, have come up with an innovative airflow system. A geared mechanism for fine tuned airflow.

This works by twisting the base, and as the base ring moves, the mechanism transmits the rotary motion to the internal gear which works like a revolver cylinder, aligning one of the five internal inlets with the only passage that directs an accurate amount of air right underneath the coil. Phew. You can watch this in action by holding the tank upside down and turning the base ring.

On the outside of the base ring you have 5 indentations which let you know which setting you are on and it audibly and satisfyingly clicks into each setting, also preventing any accidental adjustments of your airflow. There is no knurling on the base ring, just the five indentations and the two airflow slots, but I didn’t find this to be an issue at all when adjusting between the airflow options.

The airflow options on offer are 0.8mm, 1mm, 1.2mm, 1.4mm and 1.6mm.

Build DeckWotofo Cog MTL RTA Build Deck

The build deck on the Cog MTL RTA allows for a single coil build on its 22mm base. It’s really easy to build on using the 2.5mm inner diameter coils provided by Wotofo and you could go up 3mm ID, but any larger and you may struggle to fit them in without risking shorting the coils.

There are two spring loaded clamps on the build deck. As you loosen the screws, the clamps rise up allowing you to slip your coil legs under the clamps.

I used the provided fused clapton coil which was really easy to slip under the clamps and then tighten down.

As the clamps are opposite each other, you have to have your coil legs pointing out, instead of both pointing downwards. This means you can either position the coil with the legs on the top or bottom of the coil when installing. I opted to put mine on the top, as this means your coil is closer to the airhole below, hopefully increasing flavour. When I switch the coils I will try it the other way around to see how much of a difference this makes.

You also have your two wicking ports on either side of the build deck, which is where you will tuck your cotton ends into.

How to Build on the Wotofo Cog

  • Wotofo Cog MTL RTA Building On 1

I found building on the Cog MTL RTA to be really easy and straightforward. You get two coils included in the box, a dual core fused clapton coil of 0.8 ohms, and a single strand coil of 1.2 ohms. Both are Nichrome 80 and have inner diameters of 2.5mm. I opted for the fused clapton, and on both provided coils the legs are already positioned correctly to be slipped into the clamps.

A screwdriver is included in the box, so you can use that if you don’t have a dedicated screwdriver that you use for building. 

The first thing you should do if you are building directly on your mod is take out your batteries. If you don’t and you press the fire button when building you are going to feel it.

Start by unscrewing the clamps and you will notice that they will start to rise, being spring loaded. I used a screwdriver and slipped it through the coil, so I could hold it in place while installing, but you should also be able to do this with your fingers if you need to. Once the clamps have been unscrewed enough you just tuck the legs of your coil under the clamps on each side, then while holding the coil in place, screw the clamps back down. If you’re new to building it can feel like a third hand would come in handy, but you will get the hang of it with practice and a little patience!

Once the clamps are screwed down, you can straighten the coil up if needed, ensuring it is positioned over the air hole at the bottom of the deck.

When you are happy that everything is in place and your screws are tight on the clamps, you can snip the ends of the legs on the coil. Get them as close as you can.

Put your batteries back in your mod, turn it on and turn the wattage down, it’s time to dry fire these coils! I put my wattage down to 10 as these are MTL coils, and it provides plenty of power to get them glowing. You just pulse the fire button, don’t hold it down, and your coil will start to heat up. If you notice that only parts of your coil are starting to glow red, don’t worry. Stop pulsing and run your screwdriver over the coil in a strumming motion. You can also give it a squeeze with your tweezers. Make sure you don’t fire your mod when touching the coil with anything metal. If you have ceramic tweezers you’re fine, but metal conducts electricity. Keep strumming, squeezing and pulsing and your coil. What you are looking for is the coil to glow evenly from the inside out. Once this happens, you are done. Stop pulsing and let the coil cool down for a minute or two. You can blow on it to cool it a bit quicker too.

Once the coil is cool, you can wick it with cotton. Wotofo provides a bag of two cotton strips, which is the correct width to fit the coils. Each strip is long enough to provide about three wicks each. However, I found it was a little too thick to get the cotton through the coil without deforming it. I pulled a very slight strip off the cotton and this fit much better. You want the cotton to be snug, but not so tight that you will deform the coil when pulling it through.

To start, twist one end of the cotton and poke it through the coil. Grab the end with your fingers or tweezers and gently pull through while feeding from the other side with your other hand. You can pull it all through and leave just enough of a tail that it fits down to the bottom of the wicking holes. Then cut off the side you have pulled though, again leaving enough to poke to the bottom of the wicking hole on that side.

Now you can thin your cotton by gently combing it with your tweezers, and fluff and spread it. Then using your tweezers start to tuck the ends of the cotton into the wicking ports. If they just reach the bottom, that’s what you want, or even if you can see a little space between the cotton and the bottom. Don’t have them too long or your juice will struggle to get through and you’ll have dry hits. Too little cotton and the juice will flood your build deck.

It can take practice to get right, I’ve struggled in the past with some RTA’s. I did find the Cog MTL RTA to be quite forgiving though. I didn’t suffer any flooded decks or dry hits once wicked.

Lastly, you are going to take your juice and dab it onto the coil and cotton to prime it. You can quickly fire your mod while doing this to soak juice into the coil. You are just making sure the coil is saturated with juice so you won’t burn any cotton when you start vaping.

Once done, you take the rest of the tank and slip it onto the build deck, tighten it with a few twists and take off the top cap. Fill up with your liquid of choice and you’re ready to vape.

Overall, building on the Cog MTL RTA was a pleasure, really straightforward, and no issues encountered.

PerformanceWotofo Cog MTL RTA 4

So, how does the Wotofo Cog MTL RTA perform? In my opinion it performs well. As I mentioned at the beginning of the review, I’m more of a DTL vaper. But I found the Cog to give great flavour, and I enjoyed switching it up and going MTL. I enjoyed it so much that I’m now going to have two setups on the go at all times, a DTL and a MTL setup.

The included fused clapton coil was rated at approximately 0.8 ohm and came out reading 0.77 ohm. The flavour from the coil was great, no complaints at all. I found 20 watts to be the sweet spot, giving the right amount of flavour and heat for me, with a cloud production of more than I was expecting.

I haven’t used the single strand coil provided as the fused clapton coil is still running fine. I don’t want to swap it out when it’s giving me such good flavour!

Building was easy, with no flooded chamber or dry hits encountered at all over my testing period.

I also haven’t experienced any leaking from the tank at all, and this is including when it’s stuffed into my breast pocket of my motorbike jacket on my ride to work.

However, I do have to say that the draw on the Cog is a loose MTL and this is where a slight bit of negativity comes into this review. The cog’s airflow adjustment doesn’t offer that much airflow adjustment. The difference between the 0.8mm and 1.6mm feels negligible. If you switch straight from 0.8mm to 1.6mm you can tell there is a difference, but it’s not that big a difference. I would say the 0.8mm setting is still quite an airy draw, which is going to be a problem if you like your MTL draw tight. For me personally, it’s not a problem. I like it on the 1.6mm setting and I’m happy with that. But considering Wotofo state the gear mechanism allows fine-tuned airflow control, I think it does fail on that front.

The only other thing I have experienced is a slight build up of liquid under the drip tip where it connects to the top cap. I can only assume this is from vapour condensing and it can easily be removed with a tissue if you pop the drip tip off, but it can give a bit of a gurgling noise when drawing if it builds up.


Is it worth picking up the Wotofo Cog MTL RTA? I think this depends. If you are already a MTL vaper and especially like a tight MTL draw, then I would say no. You will more than likely be disappointed with the airflow options on the Cog, and already have MTL tanks that give you what you want. If you haven’t tried MTL vaping or prefer a more airy MTL draw, then the Cog will give you great flavour, an easy build, no leaking and a good amount of vapour production.

For me, personally, this is staying in my daily use. 

However, it is a shame that the whole mechanism that the Cog gets it’s name from doesn’t seem to live up to what it should have. I think the idea and thinking behind the Cog’s mechanism is great, but it hasn’t really delivered what it set out to do. Maybe with a few tweaks to the implementation of the design it can deliver, and we’ll see a Cog V2 in the future?


Daniel M Author Pic

Daniel MacGregor

I started vaping approx. 5 years ago as a way to give up smoking. I'd tried many times previously to stop, but switching to vaping finally helped me to give it up for good. Now I enjoy building my own coils and squonking on an RDA, and would love to help others make the switch from smoking to vaping.

Add comment