Saturday, February 28, 2015

Estes Proto X & Proto X SLT


I did not buy the Proto X. It doesn't quite make my cutoff for toy grade. I bought the Proto X SLT. That is just enough different to make the cutoff. Unfortunately, it also would not go into link mode to try binding with my deviationTx controller. When I called Hobbico about this, they just verified that I was doing the right thing, declared it broken, and are going to send me a new one. As soon as they are in stock. In late April. So they sent me a free Proto X to make up for the delay.
So I have to give their support a huge thumbs up. As good as any I've run into, and a much better than anything I've run into when shopping across the pacific.

The quads

This gets the opposite reaction of my last quadcopter review: That thing is teeny. When the Proto X arrived, I figured they made a mistake given the size of the box. See for yourself:
Two Proto X's, a Blade NanoQX and a quarter for scale
For the record, the two Proto X's are cross-dressed in this image. The Proto X canopy is on the Proto X SLT, and vice versa.
The original Proto X was available just in time for the holiday shopping season in 2013. It was a major hit last year, winning a couple of "Toy of the year" awards. At the time, it was the worlds smallest production multirotor, measuring 50mm (2 in) on a side, and weighing about 11 grams (0.4 oz). Since then, a number of clones and copies have come out, including a few that are slightly smaller. The reviews are that it - and the new Proto X SLT - are still one of the, if not the, best of the bunch.
The Proto X SLT upgrade showed up about a year later. It used a radio protocol that would work with hobby-grade controllers. It also had a different canopy which allowed the battery to be replaced without taking off the canopy, so they sold it as having a "user-replaceable" battery. These are the change pushed it into my "buy" category.

The differences

Even though the original Proto X battery was listed as "not user replaceable" on the Tower hobbies site, it wasn't hard to replace: four plastic clips hold the canopy on, and after that you just peal the battery off the board and unplug it from a standard pico connector. Taking the canopy off seems to stress it about as much as taking the battery out of the Proto X SLT canopy. If you want, the canopies can be swapped to give the Proto X a "user-replaceable" battery. It also means that people unhappy with the Proto X SLT only being available in blue can use one of the five other colors the Proto X canopy comes in.
The new protocol means a new controller. The original Proto X used the Hubsan X4 protocol, and could be flown with the controller that come with the X4. The Proto X SLT comes with what is essentially a Hubsan X4 controller that uses the SLT protocol. I'll cover the differences a bit later.
The PCB on the Proto X SLT appears to be slightly thicker, but that could be because it's white instead of black making it appear thicker, or because white PCBs are thicker, rather than an intentional design change.
There are no other differences that I can see, and they have very similar flight characteristics.


The secret to the small size of these quads is the integration of the frame and the flight control board. The frame is a PCB that carries all the electronics - a μ-processor, an rf module, and at least one other surface mount chip, along with a bevy of smaller bits. Power to the motors is also delivered via the frame, using a pair of arms running out to each motor.
Larger quads have integrated power distribution into part of the frame, but all the electronics? Not before this.
This does mean that repairs are going to be beyond most people. Breaking an arm will mean you need to not only glue it together, but also repair the power to the motor that goes over that part of the frame.
However, the things seem to be quite durable. No noticeable damage after numerous crashes, including wedging behind and under sofas, suitcases, A/V cabinets and into at least one mop. The worst problem seems to be losing props - the seem to pop off during even an extra hard landing.
While durability is fine, robustness - for want of a better word - is a bit lacking. The plastic motor holders are a bit loose, and those hard landings also wiggle the motors. When they get out of true, the thing will drift, including a bit of drift in yaw. This can usually be improved by checking all the motors and pushing them back in place if required, then letting the quad sit on a level surface for 3 seconds to reset. Sometimes, forcing a calibration by holding the left stick down/left and wiggling the right stick back and forth until the quad lights blink is also required. But it's still a pain, and I find myself retrimming the thing regularly.

Flying the things

Either one of these is simply flat out fun to fly.


The smaller size just makes my living room seem enormous when compared to flying something like the NanoQX. Fast figure 8's with the NanoQX are tight for space in that room. With the Proto X, there's lots of space for them.
They also have nice, bright LEDs. Being blue on the front and red on the back makes orientation obvious even in an otherwise pitch black room.
The lights blink a low battery warning. This is also nice and clear, and you have plenty of time to bring the thing down safely before running out of power.


The downside is that there's nothing like the NanoQX agility mode. So while there's plenty of room for the automated flips (especially once the trigger mechanism is fixed as described below), I can't say how it stacks up for doing manual flips, because there's no way to do manual flips.
As noted, I need to trim the quads out regularly. This is more an annoyance than anything else.

The controllers

The Proto X can be flown with my Devo 6S. This isn't supported by Estes, and not something I was aware of before buying the Proto X SLT. deviationTx just keeps adding features.

The Proto X mini controller

The original Proto X comes with a really tiny controller. A lot of the nano quads that have come out since it come with similar controllers, but I haven't used any of them. You can see how small this controller is here:
The two Proto X controllers, the Devo 6S and the Spektrum DX5e.
Until I got the original Proto X, I couldn't picture myself using any of the nano quad mini controllers on a regular basis. But the Proto X controller changed my mind about that. It's actually better than most of the RTF controllers I've dealt with. It's not as good as the Spektrum DX5e, but it's still usable. The small size makes me comfortable taking it anywhere I'm willing to take the Proto X, which isn't true for larger controllers.
The major disadvantage of this controller is lack of any kind of yaw trim. As noted, the quad sometimes needs that.

The Proto X SLT RTF controller

The SLT version comes with a larger controller. As I mentioned, it's an SLT version of the Hubsan X4 controller, and the two are otherwise identical. This immediately gives you extra features, like a yaw trim!
Holding the throttle down trim button acts like an LED power switch. It's not clear that turning them off is a good idea, as orientation with them off is noticeably harder. They still start flashing for the low voltage warning when off.
There is also an expert flight mode that can be turned on by pushing down on the right stick. This gives you a more responsive and faster flight. It also lets you do automatic flips by making the proper magic passes with the right stick. This can be disabled by pushing down on the left stick. Note that a lot of reviews of the Proto X, and comparisons of it with other nano quads, will downgrade the Proto X as not being able to do flips. This is misleading. The Proto X is perfectly capable of doing flips, just not with the controller it comes bundled with.
This is, without a doubt, the best RTF controller I've ever used. The gimbals aren't great, but they're up to the DX5e quality. Unlike the DX5e - and all other RTF controllers - the rates aren't fixed. The actual rate used for each is adjustable, and you have separate settings for yaw, pitch and roll controls. Having two adjustable rates is much better than having four or five fixed rates. Especially when the big selection just lets you pick between behaviors you'd like to avoid, as opposed to being able to eliminate them.

And the real deal

As stated, the reason for getting the SLT version was to use it with my Devo 6S. Probably a bad decision on my part, as that costs more, and I can fly the less expensive version with it as well. Since that one has been around longer, deviationTx support is better than for the SLT version. In fact, at this point it's not clear that deviationTx's implementation of SLT will work with the Proto X SLT.
Doing so brings another upgrade in the gimbals. And another new set of features. For instance, the thing has telemetry! It reports the battery voltage back to the controller. While this serves little purpose on a small indoor quad with nice, bright LEDs, it does make me want to throw one at whoever at Blade decided the 200SRX didn't need that feature. I recommend not using it, as it seems to reduce flight times.
The hobby grade controller means you have a throttle hold, which I consider crucial for safety reasons. The rates and LEDs can now be put on switches, instead of being on buttons or sticks. I've programmed mine to do automatic flips with simpler gestures. This works in low rates mode, which the hubsan flip doesn't do. I'd still prefer a real agility mode, though.


I really do recommend this, for pretty much everyone. It's a lot less expensive than the Blade NanoQX, which is the only indoor flyer that I'd rate as better than a Proto X. Especially for beginning flyers, since the agility mode that makes the NanoQX better won't do them much good.
If you've got a hobby grade controller or the Hubsan X4 controller - or plan to get one of those - get the original Proto X to get that mini controller. Otherwise, the larger controller that comes with the SLT version is well worth the extra $10 or so it costs.