Testing the Immersion RC Vortex 150, Part 2

By Terry Dunn

For experienced pilots, the Vortex 150 presents a high-performance ride in a turnkey package.

In a previous article, I examined the features and assembly process of the Vortex 150 race quad. This time around, I'll get this little beast in the air and see how it performs.

Flight Modes

The Vortex's flight controller has three default flight modes: Angle, Acro, and Horiz. You can select any of these modes during flight with a 3-position switch on your transmitter. Angle mode limits the quad's maximum pitch and roll angles and provides self-leveling when the controls are neutralized. While this is the easiest and most forgiving flight mode, the angle limits rule out any aerobatics.

Acro mode is the same thing that many flyers call Rate mode. It provides no self-leveling features or angle limits. Acro is definitely the most challenging mode to fly. Yet, it also provides the most precise control of the quad. It's like the difference between driving a car with an automatic transmission (Angle mode) and one with a manual transmission (Acro mode). It takes practice to get the feel of it, but the results are worth it.

The Vortex 150's flight controller is preprogramed with three flight modes. The Acro (rate) mode is especially smooth.

Horiz mode is a hybrid of Angle and Acro modes. During normal flying, it behaves like Angle mode. When you input large control movements, however, the bank limits disappear and it responds as if in Acro mode. You get the safety net of self-leveling, along with the ability to perform flips and other aerobatics. If you intend to eventually master Acro mode, Horiz is a great way to transition away from Angle mode.

First Flights

Before donning goggles with a new FPV ship, I prefer to start off with some Line-of-Sight (LOS) flying. I think this gives me better situational awareness while I get the feel of an unfamiliar model and work out any control kinks. I was a little concerned about LOS flying with the Vortex 150. It is so small that I thought I would lose visual orientation before it got very far away. Given its racing pedigree, it can get far away very quickly.

I was very surprised to realize that I could actually fly out a good distance and still tell which way the quad was pointing. The video antenna sticking out like a shaggy tail was a handy visual reference. I logged a few successful LOS flights, spending a little time in each of the flight modes. Everything worked well and the Vortex responded crisply to the controls.

Despite the small size of the Vortex 150, the tail-like VTX antenna makes in-flight orientation surprisingly good for line-of-sight flying.

For FPV flights, I've been using my new Fat Shark Transformer HD unit. Most of the time, I use the full-screen headset configuration. This unit matches up well with the Video Transmitter (VTX) in the Vortex. I've been flying with the VTX set to 250 milliwatts of power output (it is capable of up to 600 milliwatts) and I have not experienced any reception issues at all. Your results may vary depending on the conditions in your area.

Angle mode may be the most beginner-friendly flight mode, but it is not tame by any standard! The Vortex 150 has ample power to blast skyward and get moving at a fast pace. I thought that all of the default control settings in Angle mode resulted in a well-balanced and responsive feel. Actually, I like the default settings on all three of the flight modes. I haven't changed a thing.

Fat Shark Transformer HD FPV goggles are a good match with the built-in video transmitter and camera on the Vortex 150.

Horiz mode feels a lot like Angle mode. The only difference is that I'll jab the controls on occasion to perform flips and rolls. It's a lot of fun, while still being relatively stress-free. For a long time, Horiz mode and its similar cousins found on other flight controllers were my preferred mode when flying race quads. But I recently decided that I needed to buckle down and really invest some time getting comfortable with Acro (Rate) mode.

I've always thought that Acro mode is considerably easier when flying FPV rather than LOS. Seeing the horizon in your goggles is a better reference for level flight than looking at the quad in mid-air and trying to discern if it's tilted at all. I found that to be especially true with the short-armed Vortex. But that's okay. These machines are meant for FPV flying.

I've been really surprised by how manageable Acro mode is. With my other quads, I tend to search for level flight after a flip or high speed pass. I invariably over-correct and oscillate before I get things leveled out. I don't have that issue with the Vortex 150. Maybe the stock control settings are more exponential than linear (which softens control response near mid-stick). Or maybe it's because of the lower angular momentum and moments of inertia of a lighter and more compact quad. I don't know. Whatever it is, I really like how the Vortex 150 handles in Acro mode.

While not appropriate for rank beginners, the Vortex 150 can be flown by pilots who have mastered the bare rudiments of multi-rotors.

I feel like I'm in complete control of the Vortex at all times. That confidence has encouraged me to fly much more aggressively than I normally would with my other race quads. Sure I still bobble from time to time. Okay…I bobble a lot. But it's not a big deal because I don't stress about whether the quad will crash before I can recover. I can tell that my flying skills are steadily improving.

Race quads inevitably lead hard-knock lives. While I've had a few rough landings with the Vortex 150, I haven't yet cuased any incidents that really tested its durability. Even the original propellers are still going strong. I'm sure that a big fall is coming sooner or later. I suspect that the Vortex's small size and light weight will pay dividends here as well.

On the Clock

When using the 4S-460mAh battery, my flight times are only around two and a half minutes. It is invariably a very exciting 150 seconds of flight. But the time passes quickly. Make sure that you have several batteries on hand.

Thanks to the built-in on-screen display, I can monitor several parameters during flight. I've seen peaks of 28 amps during hard climb-outs. This is still within the burst current limit (41 amps) of the Lumenier 4S-460mAh 45C batteries that I'm using. The batteries, however, do get pushed rather hard in this application. They are usually quite warm at the end of a flight. I let them cool down completely before recharging.

The Vortex can fly with 3-cell or 4-cell batteries. I sometimes use this Flight Power 3S-800mAh battery for longer flight times (and reduced performance).

The Vortex 150 also flies well on 3-cell batteries. Even with the lower voltage, the model has plenty of power for fast and aerobatic flights. The performance is just a few notches below the 4-cell setup. Using a 3-cell battery also results in lower amp draw at full throttle. With the dual factors of less current and higher capacity, I can usually get 5 minutes or more of flying with the Flight Power 3S-800mAh 25C battery that I've been using. I plan to experiment with higher capacity 4-cell batteries as well. It's all a delicate balance between performance and flight time.

Final Lap

I wouldn't recommend the Vortex 150 for someone completely new to flying. But I think that anyone who has become comfortable with cheap indoor quads or an aerial photography rig (like a DJI Phantom) could transition to race quads relatively easily with the Vortex in Angle mode. Starting out with a 3-cell battery would help as well. There are plenty of options for boosting responsiveness and power as your skills grow.

For experienced pilots, the Vortex 150 presents a high-performance ride in a turnkey package. It is a racing-caliber machine that doesn't demand much time to get flight-ready. I've been using it to transition from 250mm racers and get a feel for the handling of the new, smaller racing quads. The differences have surprised me. The Vortex has also been a great model for sharpening my rate-mode flying skills. I intend to keep pushing myself and the Vortex in order to become a better all-around quad pilot.

Terry is a freelance writer living in Buffalo, NY. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.