COMPARISON REVIEW: Nano S2 & Nano CP X

[xoexoe]

I have many months of experience with both the Nano CP S (2nd gen) and the Nano S2 (3rd gen). But I've never flown the 1st gen CP X. Multiple people here on HeliFreak have said that that the original Nano flies quite differently than either of the later two models, even in 3D mode. Must admit, I’ve always been curious.

Well, a few days ago I acquired a CP X from a fellow HeliFreak (thanks Chris!) and have put enough packs through it to give an initial review/comparison. I am writing this as someone who is most familiar with the S2 and will use its behavior as a basis to describe the CP X.

Both helis had the HH brushless mod installed.




Three-sentence summary

The Nano S2 is more stable, but the CP X is more fun. The S2 is a great trainer for learning maneuvers that with rudder movements that rely on piro compensation, while the CP X is better geared for high-cyclic 3D maneuvers. Both are great and serve different purposes.

Piro compensation: The good

Pirouettes are easier on the newer Nano S2. Plain and simple. This is where the newer model's introduction of piro compensation really shines. The S2 will better serve the pilot who is just learning upright/inverted orientations and stationary piros. The ability to crank the rudder stick and not worry about cyclic input as much—I say as much because the compensation is not perfect—cannot be understated.

With the CP X, constant macro cyclic corrections are needed during stationary piros. (While I'm no pro pilot, I found it nearly impossible to do fast-moving piros on the CP X. In fairness, it was quite difficult on the S2.) An experienced pilot will not have much trouble dealing with the lack of piro compensation, but it will create a larger hill for the newer pilot to climb.

Piro compensation: The bad

I have always felt that the Nano S2 was fighting my cyclic input while it was pirouetting. For example, imagine the S2 is pirouetting and you give a short burst of down-cyclic when the heli is tail-in. It ought to begin to move toward toward you and maintain that travel direction; at least bigger helis with proper FBL units would do so. But the S2 doesn't do that. Instead, the S2 rotor disc will quickly level-out and the heli will go into a stationary piro again. To get the S2 to continue traveling toward me, I would need to give a few more bursts of well-timed cyclic (or better yet, a slight stir of the cyclic).

Another way to say this is that the S2 sometimes feels like it's in some sort of Blade-SAFE stability mode even though it's nominally in 3D mode.

Now, I'm not saying the CP X will behave exactly like a proper larger heli if you go from a stationary piro to a moviing piro—it won't because of its lack of any sort of piro compensation. But at least it's not artificially stable.

Cyclic agility: So different!

Cyclic maneuvers like flips or agressive rainbows are quicker and easier on the CP X. This was my favorite part of flying the older model and why I found it more fun. The CP X feels similar to my T-Rex 150X or even my Oxy 2 with regard to how precisely & quickly I'm able to flip it.

In comparison, the S2 feels sluggish, especially elevator moves. In fact, after flying a few packs through the CP X, I did two things: (1) I gave more negative expo on my S2—right now I'm at –35%, which for Spektrum means more sensitive around center—and (2) I gave a fair bit of positive expo on my CP X—I think I'm around +15% now. Even with these drastically different exponential values, the CP X is quicker to flip and more enjoyable to go crazy in the air. I might need to go to –50% on the S2 for the two helis to even begin to feel the same.

(By the way, I even set up the two helis to have approximately the same max cyclic pitch. They really do fly differently! I will likely need to increase the S2's aileron and elevator travel endpoints on my TX.)

More than once I've seen HeliFreak posters say that the CP X was better than the CP S or S2. If I'm being honest, I thought they were just being cranky and basically saying "I never even touched anything with an accelerometer [like CP S & S2] and neither should you!" But I now better understand what they were saying. If I could rephrase this sentiment in terms of someone like me who is still relatively new to helis: The CP X will allow you to do more high-cyclic 3D maneuvers, whereas the S2 is slower, more stable, and more sluggish. This is again one of those cases where I think the S2 is better to learn on, but as soon as you look up the Game Genie code to unlock a certain maneuver, you're gonna want the CP X's agility. At least I do.

Can't do throttle curves on the S2. WHAT?!

There's a "feature" of the S2's FBL firmware that locks the throttle at 100% no matter what throttle curve you set up in your transmitter. Want a slower head speed with the S2? Sorry. Want to set up a V-curve in your transmitter so that you maintain constant head speed? Sorry.

You might say that on a tiny micro like the Nano S2 or CP X, 100% is fine, no big ideal.... That is true for me now, but wasn't true for me when I was initially learning to fly collective pitch helis. Back then I actually wanted a non-reactive head speed. 60%? Yes please! But even if someone is not an absolute beginner, the lack of ability on the S2 to customize throttle curves means that you can't maintain constant head speed as the battery voltage decreases during a given flight. On both my CP X and my T-Rex 150X (which don't have governors), I have different sets V-curves, one for the beginning of the pack when the voltage is high and another one for when the battery is about half spent and I need to simulate a governor by manually bumping up the power output (e.g., 80-68-65-68-80 and 100-88-85-88-100). With the S2 I don't have this flexibility. But I do with the CP X.

Horizon Hobby, why did you do this with the S2? Or was it unintended, as I suspect it was? (Given the existence of the firmware bug with throttle hold/cut on the Nano S2, my money is on it being unintended.)

Final word: Which do I like better?

There are features of both the S2 and the CP X that I like and don't like. I can best summarize it by describing what my ideal "Nano S3" heli would be: it would have the piro compensation of the S2 but the agility and customizability of the CP X.

I will be flying both helis. If I want to practice my aileron or elevator flips or aggressive rainbows, I'm gonna break out the CP X. If I want to practice small-radius nose-in or tail-in circuits (or anything else that requires constant rudder), I'd do the S2.

Both are great in their own way and serve different purposes.

Bonus video: First flight with the CP X

I filmed my very first flight with the CP X. Obviously the thoughts I communicate during the video were not as well-formed as they are now, so what you're seeing are just my initial impressions.

First flight with Nano CP X — Comparison to Nano S2 (11 min 3 sec)

[fiddle]

Originally Posted by xoexoe

Another way to say this is that the S2 sometimes feels like it's in some sort of Blade-SAFE stability mode even though it's nominally in 3D mode.

I feel the same way! It makes it hard to fly as it is different than everything else including the simulator.

[Chris1683]

You hit the nail on the head with your review!

The original CPX was classified as an intermediate helicopter for those very reasons that you mentioned. There was much less artificial stabilization and it made the pilot learn maneuvers in the more traditional sense. The S2 relies a lot on firmware for keeping it stable and for this reason, many people who fly it feel like their skills actually degrade when they go to fly their bigger helicopters.

I’ve owned and flown all 3 Nano’s and what you say is true. The S2 is great for beginners. The CPX is a great little heli for when you are ready to step up your game but don’t want to get out of the Nano category.

The point you made on expo values is also very true. On the S2, it’s very mushy and most people like flying it with negative values to gain more control. On the CPX, I have found that +30% is great for mild and 3D flight.
I also increased my servo endpoints for aileron and elevator to 105/105 and it gives it a little extra punch.

To increase the stability even more on the CPX, you can add a set of bulleted blades. They do make a noticeable difference. I suspect that is why Blade discontinued all of the High Performance blades for the Nano and only include the fast flight bulleted blades now with the Nano.

Enjoy your new CPX and keep the sweet videos coming!

[navigator2011]

Originally Posted by xoexoe

Three-sentence summary

The Nano S2 is more stable, but the CP X is more fun. The S2 is a great trainer for learning maneuvers that with rudder movements that rely on piro compensation, while the CP X is better geared for high-cyclic 3D maneuvers. Both are great and serve different purposes.
...

Wow, Xoexoe! That is a blog-level review and comparison! Thanks a bunch for taking the time to share your thoughts and post them here. I always love to watch your videos too -- keep them coming!!!

Originally Posted by Chris1683

You hit the nail on the head with your review!
...

I’ve owned and flown all 3 Nano’s and what you say is true. The S2 is great for beginners. The CPX is a great little heli for when you are ready to step up your game but don’t want to get out of the Nano category.
...

One thing is for sure, the S2 has done a great job at teaching me to fly around inverted. And, the moves I learned with the S2 have transferred over very well to my 150X, for example.

But even so, what is missing are intermediate-level nanos and mcpx-sized helis for people that are growing beyond the beginner phase but lack enough space to fly bigger helis. I sure do hope that HH takes this to heart.

[xoexoe]

Thanks!

For sure. I’m glad I have my S2. Fear-free flight with zero-cost crashes and stable piros is veerrrrry nice. Love it.

[navigator2011]

BTW, Xoexoe, I did notice the cyclic wobble in your S2. When mine was doing that it was due to a combination of vibes and torn rx board dampeners .

To be specific, I had a snapped lower canopy post on one side and a torn dampener on the other side. So, my board was basically dangling from the top dampener. Now, I've eliminated the vibes and installed a new frame, the wobble is gone even though I still have one torn dampener.

[xoexoe]

Wish it were that! No broken anything. This S2 has done that out of the box, new. I tried trouble shooting by either switching boards or switching servos (I can’t remember which, of course) and it was still there.

In the video one of my servos sort of bottomed out and I needed to spin the exposed gear manually it to get it unstuck. I’ll try replacing the servo. But if I still can’t figure it out after that I’ll make a proper thread on trying to fix it. I’ve got spares of everything now.

And Chris, I will try the bullet blades on the CP X this week. I’ve got too many of those lying around to count.

[navigator2011]

The tear is not directly observable just by looking. Mine torn at the narrow point that fits inside the hole in the board. So, be advised.

In any case, I look forward to hearing about your experience with fixing your S2!

[lahannsven]

Still a word to XoeXoe’s perfect review.
I set for the Nano S2 an Expo of -55%.
Only then you can use it as a trainer for a larger heli ( in my case Trex700L).

Otherwise with Expo 0% you have a Blade Msr likely beginner heli.

Irritating is the possible Nano S2 3D mode for a beginner heli. People think it is in advanced mode, but it is then in a “3D” beginner mode. Somehow absurd.

Maybe the newest heli generation is much more automated and the heli pirouettes itself without pilot interaction . A more automated drone concept — the pilot can drink a coffee and the heli does 3D tictocs.

[Chris1683]

Decided to take my Nano out for a flight today before the storms roll in!

Blade Nano CPX - Summer 3D Flight (4 min 6 sec)

[navigator2011]

That's great flying! Thanks for sharing!

Meanwhile, your CPX's tail looks pretty solid. How would you compare the tail hold of the CPX compared with the S2? My CPS's tail hold is flimsy at best--weather-vanes even with zero vibes.

[Chris1683]

Originally Posted by navigator2011

That's great flying! Thanks for sharing!

Meanwhile, your CPX's tail looks pretty solid. How would you compare the tail hold of the CPX compared with the S2? My CPS's tail hold is flimsy at best--weather-vanes even with zero vibes.

Thanks! The tail holds very well on my CPX with the solid stretched boom. This season I have been concentrating a lot more on backward flight and so far I have not suffered any tail blow outs.

[navigator2011]

Thanks for getting back to me! Your video makes me wonder if I should track down a Nano CPX.

[xoexoe]

Chris: Awesome flying! In the beginning you were doing backwards flight. Looked nice and controlled. I can’t even do that flying forward. The more I fly the more I can appreciate maneuvers that I used to think nothing of. Not because I thought they were easy, but because I had no idea just how much practice goes on to them.

navvy: Can’t hurt! I’ve got an itching to fly a little micro, and it isn’t the S2 (though I wouldn’t mind that either). Too bad the weather here has turned sour.

[Ah Clem]

xoexoe,

Excellent thread! Great information!

My KBDD Blades came in today, so I should have my S2 flying shortly.

I am very interested in seeing the differences you pointed out for myself!

[Ah Clem]

"There are features of both the S2 and the CP X that I like and don't like. I can best summarize it by describing what my ideal "Nano S3" heli would be: it would have the piro compensation of the S2 but the agility and customizability of the CP X."

I could not agree more.

After flying the S2 this morning for the first time, I too find it more stable, but less agile than the original CP X.

I ended up setting the aileron, elevator, and rudder end points at 125%, and putting 25% negative expo on aileron and elevator (I will be adding 25% negative expo to rudder before I fly it next). This aided the agility a great deal.

It does stay put much better while pirouetting, which is useful.

That being said, it does fly extremely well-it is just different and will take a bit more getting used to. It also flies a bit more like a larger machine, which in the long run, is probably better too.

My S2 has a great deal more power than my X (I have ordered and received a new motor for the X), which I attribute to the very high air time of the X.

One other thing that is better is the tendency for the machine to shudder when the head is unloaded and the ship is upright. In the two flights of the S2, I only noticed it shuddering once, and to a far less degree than its older relative.

Good improvement all the way around!

I am looking forward to flying it more, later on in the day (when it cools off a bit).

[thundercatfpv]

Hey how's it going, thanks for the review. I noticed that you fly your Nanos with your FRSky Horus. I to use the iRange Module but only with my non-collective pitch helicopters, drones and planes. although, I have not been able to set up my blade nano CPS. will you be willing to share your configuration or even better, your .eepe file? Thanks

[xoexoe]

I can post my entire .otx configuration file next time I’m in front of my computer; which should be in a couple hours.

[Number]

I have a Nano S2 model in my radio as well... link in my signature. You will probably have to mess around with switch assignments since my switches are different from the stock positions and styles.

[xoexoe]

Here is mine. Change the .txt file to .otx.

As Number did, I moved some of my physical switches around.