OBS Crius RDA Review - Photo Album with more photos
The OBS Crius is a pretty standard looking 24mm RDA. I received the black one that has a sand blasted matte finish a lot like the full black Dead Rabbit. Liquid smudges on it doesn't look as bad as the Dead Rabbit but they still stand out. It's usually not a problem because it's very hard to make this RDA leak and there's usually no condensation around the outer airflow slots.
The machining and general finish is superb on this RDA. I'm not a big fan of the silver OBS and Crius written on the sides but it's done very well. It looks more expensive than it is. It comes with a bottom feeding pin installed, and a little screw that closes the BF hole to use with regular mods.
According to OBS product page the RDA comes in black, navy and stainless steel. I've only seen the black and the SS up for sale. Interestingly the box it came in has options for rainbow, green, orange, red and gold but no mention of those colors on the internet.
The RDA supports dual coils only. Being a single coil fan I'm a little disappointed by that. If it's not possible to have cutouts for single coil on the AFC cap I wish companies would include a single coil AFC cap or sell them separately.
The Crius supports 810 drip tips and doesn't come with a 510 adapter. The included ultem 810 tip is a little different. It has an unusually narrow bore compared to other 810 tips. The walls are hollow where juice ends up collecting and it looks pretty bad. I wish it was a solid block so that wouldn't happen, and it would probably insulate heat better as well.
There is no dome on the top cap, just a slight rounded bend. A dome wasn't really feasible since the RDA has two barrels on the top cap.
Airflow system
This OBS Crius RDA channels its airflow sort of like how the OBS Engine Nano RTA, or more specifically the IAI RDA does with a little twist. It sucks in air through four evenly spaced slots on the outer barrel and channels it to the coils via two slots positioned adjacent to them. The slots on the outer barrel are placed higher than the ones on the inner barrel to catch any spills in the valley between the two barrels. The design makes it very leak resistant and any collection in between the barrels can be cleaned very easily at your convenience.
I was a little confused on how the airflow worked before I received the RDA. I drew the following diagram to help explain it better. OBS claims the four holes sort of create a vortex but I'm not familiar with aerodynamics enough to affirm or dispute that.
The airflow control ring makes an excellent seal with the outer barrel. When you close off all the outer slots you don't get any air when you pull. When the outer slots are wide open there is plenty of air coming in for a very lose draw. This RDA can go from super restricted to super loose draw. Thanks to the inner barrel making the chamber very small, you can throw on a 510 adapter and a 510 tip and get a pretty decent MTL experience.
So does this unorthodox airflow system make a difference? Well aside from the leak resistance, I initially thought the goal of this design was to increase air pressure going into the coils, especially when the slots are wide open. In practice it actually does work. I tried blocking off the two outer slots furthest away from the inner slots and noticed a difference.
When the slots are wide open blocking off two of the outer slots does make a noticeable change in the amount of air, but there's so much air that it doesn't really matter. There's still plenty of air going into the coil for a super loose draw.
The more you close off the outer slots, the bigger difference it makes when you close off two of them. I feel that leaving the outer slots open a quarter way while blocking none of them feels the same as leaving the outer slots half way open while blocking off two of them.
So I don't think the airflow system is increasing the pressure or speed of the air going in, it's just giving you a little bit more air in an RDA that already can be made pretty airy. However I do find the flavor a little better when all four outer slots are open. I don't know if it's just in my head but I definitely prefer airflow through all four slots. I thought the design was a little gimmicky at first but I don't feel that way anymore.
The airflow system is slightly louder than your typical RDA, especially when all the slots are open. I guess that's a side effect of channeled airflow. Funny enough the RDA is a lot quieter when blocking off the two outer slots closest to the inner slots.
Build deck
This has got to be one of the easiest decks to build on. The positive (top) and negative (bottom) posts are separated by a insulator made of Zirconium Oxide. There is only one screw to tie everything together and it's spring loaded. You unscrew it a little bit and the Zirconia block separates from both the positive and negative posts. Install your coils and simply tighten the screw to lock the legs in position. There is ample room to get the cutter in there and clip the legs.
I've tried vaping at ~100 watts for 10 minutes or so and there were no marks or signs of failure on the Zirconia block. It wasn't fun.
The posts can accommodate pretty thick wires. They also won't twist up flat and wide wires. You can wrap your coils clockwise or counter clockwise.
There are notches on the deck that locks the top cap in place. It's an awesome feature because you won't lose grip unscrewing the atty or adjusting the airflow. More attys should have this feature. It's also necessary for this RDA because you can't see the inner airflow slots to line up with your coil when you're putting the top cap on.
The juice well is pretty deep. It's hard to get an accurate measurement because of airflow slots on the inner barrel. According to my best estimates it's about 10mm deep.
It has squonk holes on both sides of the center post. One thing to note the holes are just ~1.5mm above the deck. I don't really have much experience squonking but AFAIK people like the holes to be a little higher than that. As I understand after a squonk the juice would saturate the wicks and go right back into the bottle leaving pretty much nothing in the well. This seems like a wasted opportunity because the juice well is pretty deep and the airflow system was designed to minimize leaking.
The O-rings for the drip tip and the top cap are nice and tight. They work very well. The o-rings around the deck however are too thin/long. The top cap is really easy to take off and that's very annoying. I don't know if it's like this on every unit or just my one.
The inner barrel of the top cap folds at the top and covers your view of the deck. So unlike most RDAs you can't take just the AFC cap off and take a peek at the deck to see how much juice you have left. The outer airflow slots also sit higher than the inner slots so you can't peek through the airflow slots either. Since you use part of the top cap as the juice well like the Dead Rabbit, it makes near impossible to see how much juice you have left in the well. Because of all those points it's really hard to get rid of the excess if you over drip. I got a lot of spit back when I over dripped once, opening up the slots all the way and taking longer puffs helped with that. Knowing how full your deck is by feel will take some getting used to. If you're on temp control at least you won't have to worry about accidental dry hits.
