Monday, December 28, 2015

FAA UAS registration requirement

If you aren't aware of it, the FAA recently created rules requiring pilots of unmanned aircraft systems (UAS) to register them.   I believe they are a violation of the law passed by congress, specifically the special rules for model aircraft, which I have already posted.

My comments to the FAA are:

Wednesday, October 7, 2015

RC blog entry on my programming blog

Just a short note to refer to the latest post on my programming blog, which is a close look at PWM input. It's an overview of the various methods of inputting a PWM value using an Arduino microcontroller, which is not something I've ever wanted to do outside the RC context. However, it includes code, so the post went to the blog, which has a repository for such.

Thursday, September 3, 2015

Roll Sensor for an RC Yacht

Roll telemetry data

I'd like to get telemetry from my RC Yachts beyond Rx voltage and RSSI info. For instance, the "optimal heel angle" seems to vary depending on who you listen to, so getting heel angle would be a nice start.

There are lots of cheap sensors that can report this, but none are targeted at yachts. So I'm going to build a simple one. Since I can't find rc radio gear that supports such telemetry, I'm going to hijack flight pack voltage on an aircraft system. Just read the roll angle from the gyro sensor (an MPU650 in a GY-521 board), convert that to a number between 0 and 255, then output that as a PWM value via a D->A circuit to get a voltage. The advantage of using an analog voltage sensor is that any radio system with flight pack telemetry can do this.

Thursday, June 11, 2015

The Joysway Orion


The Joysway Orion is another departure, being a sailboat. Or, as those in the hobby put it, an rc model yacht. If you're not familiar with such, you might want to read my introduction to it.

Thursday, April 2, 2015

HobbyZone Sport Cub S Review

The reason

Yup, this one is weird. The wings don't move! Not something I usually do. However, I like scale aircraft, and those aren't very popular for helicopters, at least not compared to aircraft. So scale copters are rare, and hobby grade ones tend to be expensive. I can find a number of airplanes I'd like to fly that cost less than a simple pod-and-boom helicopter of similar quality, never mind the cost of putting a scale fuselage on it!
So I bought this to learn to fly fixed wing, as that's what it was intended for. I also picked up a pair of floats for it, because - well, they were nearly free and look very cool, which is the point!

The aircraft

The Sport Cub S is an ultra-micro scale model of the Cub Crafters Sport Cub, which is a variant of the legendary Piper Cub. At that scale, it's missing most of the struts, and there's no cockpit detail, but it's about as close as similarly priced toy grade helicopters - and it's hobby grade. In particular, it has a steerable tail wheel, which is a nice touch in a an inexpensive model.

Saturday, March 14, 2015

A plea to the model aviation community

Our legislative problem

Unless you've been incredibly busy flying (in which case, I'm jealous!), you will have noticed that a lot of jurisdictions are considering, or have enacted, laws governing model aircraft. Actually the laws usually deal with drones, or if you have better educated politicians, unmanned aerial vehicles or systems.
These laws are a problem for us, the rc model aircraft enthusiasts, because they almost always include our models. Nuts, in at least one case, it unintentionally included kites!

Thursday, March 5, 2015

Some FCC regulations

More legal documents

Since one of the things I advocate is tinkering with the radio, I thought I might point out what the US Law has to say about that. After all, they regulate what you do with radios, and all the ones I have come with FCC ID numbers on them.

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.

Friday, February 6, 2015

The law about model aircraft

Drones, the FAA, and the law

There's been a lot of news about "drones" lately. Actually they're just multirotor model aircraft, but the press can spell "drone". Mostly about people flying them in unsafe or undesirable ways. The FAA has responded by issuing fines and proposing regulations, and there's been a lot of blog posts and comments and in general hot air about what the FAA can and can't do, and should or shouldn't do, and so forth. There's even been some judges ruling on things - and then being told they were also spouting hot air. And yes, I've been responsible for my share of most of the above.

Here, I want to try and provide light, not heat. The most recent act of congress dealing with model aircraft flight is the FAA Modernization and Reform act of 2012. I'm just going to quote the actual text of the act. I have cleaned up the formatting some but have not altered the text. I'm not going to comment on it or offer my interpretation - I'm sure we'll get a lot of people doing that. I'm just going to quote it so people who want to comment on it or offer interpretations have a chance to read it before doing so.

Thursday, January 29, 2015

Phoenix Flight Gear polycarbonate 200QX frame

The why

I normally like scale-looking things. For multirotors, that doesn't make a lot of sense, but I still like the enclosed body look over the open frame, let it all hang out look popular for miniquads.
The downside of this is that you have a battery compartment. For larger multirotors, this isn't an issue - there's lots of room, and a switch won't add much weight. But for the 200QX, getting the battery in is a squeeze, so using even a slightly larger battery won't work. And the battery cover is under a bit of pressure for the 3C battery Blade recommends for it.
So when my 200QX frame finally succumbed to my flying skills, I decide to try a miniquad frame replacement. Since I was going to put all the electronics on display, I decided to go with it, and got the Phoenix Flight Gear Polycarbonate Frame. I'm not providing pictures - they have lots of very good ones!

Tuesday, January 27, 2015

WLToys V323 Review

The gift

My son bought me a WLToys V323 as a gift this holiday season. Great choice on his part - it isn't going to be better than the Blade quads I already own. But it's a size I don't own - being larger than my 525 quad build, and a configuration I don't have, being a hexacopter instead of a quadcopter.

First impressions

Odd gods, but the thing is huge. That was also my sons impression. It's 550mm between diagonal rotor hobs, which is over 50% larger than the Blade 350QX's 350mm between diagonal rotor hubs. Add in the huge styrofoam prop guards, and well - it's huge.
See for yourself. Here it is next to my 350QX:
Beyond that, I tend to avoid WLToys because they have miserable quality control. One of the front motors died about two batteries into it. The seems to be a common problem on this and other multirotors that use it's motors. Fortunately, they are the same for clockwise and counterclockwise rotors, and are cheap, especially in four-packs.


It's got a typical set of features for a modern multicopter from WLToys. In fact, it shares parts with the more popular V262, V333 and V353 quads - thought it does use more of them. That's all to the good.
Let's just take a quick look at them.

6-axis gyroscope

This has the usual modern 6-axis gyroscope. It will hold a hands-free hover reasonably well. Not particularly great, but not bad for a multirotor without a GPS system.

Headless mode

There is a headless mode that can be accessed by holding down the video button. It works fine for a brief test, but reviews on other WLToys multirotors are that the hold direction drifts after a little while. The RTF transmitter beeps continuously when you are in headless mode, and was so annoying I couldn't stand to fly it that way for more than a few minutes.


Well, I've been told that flips are de rigueur these days, and yup, this one has them. It works, but you tend to lose a lot of altitude with the canopy on. I'm not sure why you'd want that feature on something that seems to be a camera platform, but it's one of the signs that this is a toy-grade copter.


This is also sold in an FPV format, and that it's a camera platform seems to pervade the design. It uses the same camera connections as the V959 and V2x2 multirotors and the V912 helicopter. Here's some raw footage that was filmed with a now three year old V959 camera on it, flying the Café Steamers mod.


There are some things about it that are either annoying or out-and-out misfeatures.

Battery tray

The battery tray wraps the battery pretty completely, leaving no way to remove the battery without pulling on one of it's cords.

Other attachments

While the web sites that sell parts for WLToys aircraft list several other V959 attachments as being for this hex and other similar aircraft, that is a lie. The camera is the only attachment that will work on this. If you're not sure, check the flight control board to see if there are connectors labelled for the ones you're interested in.

Still pictures

Whenever you take a still picture with it, it takes three - and then writes them out. On my old camera, this takes nearly 20 seconds, and it's easy to want more pictures before that amount of time has elapsed.

150 meter range

This is advertised as having a 150 meter range. I can see orientation on my 350QX at over 200 meters, so the V323 could easily be flown to beyond that distance. However, when it loses the radio connection, the motors just stop. This leads to it simply falling from the sky. Since the hex reconnects automatically, flying out of range can produce some heart-stopping behavior.

This failure mode is disappointing - and dangerous. Not having an altimeter means it can't make a controlled descent under those conditions, but setting the rotors to a slow descent should be possible. Likewise, without a GPS module it's going to get blow around by the wind - but that's true if it's in a free fall as well. This makes me worry about what will happen if someone flies it out of range of the RTF transmitter.

Flying the thing

But what everyone wants to know is how does it fly?

In general

The color scheme makes keeping orientation hard. The only difference is the two red props on the front - everything else you see from the ground is black. Until you get some altitude, the center of the canopy and prop guards can hide the two red props.

At night, the white LEDs on the front stand out and can keep you oriented, but the other four LEDs are flashing different colors, which is distracting. The LEDs aren't visible from any distance during the day.

One thing I did find out is that it doesn't compensate for a malfunctioning rotor, so you don't get any extra reliability. This means that it being a hexacopter instead of a quadcopter is simply an oddity, other than how it changes the flight characteristics - so lets look at those.

The RTF transmitter

It came with a transmitter - I don't think it's available without one. Unfortunately, I found it a major pain to fly with the RTF transmitter. That has four rates: 40, 60, 80 and 100%. It starts out in 40% rate, and flew about like I'd expect it to - slow and stable. The yaw was unreasonably slow, though. I figured that was just because they lowered the yaw rate as well.

Turned out not to be so - the yaw rate wasn't any faster in 100% mode. On the other hand, the transmitter seemed to have a dead band around center on the cyclic control stick. Small motions were ignored, but giving it enough cyclic to actually moved caused it to jerk down in the direction you wanted it to move before it started starts moving.

60% was still painfully slow, and 80% had also had the dead band issues. I pretty much gave up on the RTF transmitter after the motor died, and set it up on my Walkera Devo10.

With deviationTx

Fortunately, this can bind with a Devo transmitter running deviationTx with an NRF24L01 module installed. All of the features but headless mode work, which I consider an improvement. I don't use such even if it works well, and tend to configure transmitters so it can't be used. Flip mode as a switch works - throw the switch, and it automatically flips at max cyclic movement until you turn the switch off.

The V323 flies much better with that transmitter. There is no dead band, and it responds smoothly at 100% rates. I do use some expo to make things a little less sensitive near the center. I can even get a tolerable yaw rate by configuring the rudder to a 150% rate.

It still isn't as responsive or stable as the 350QX - but it also costs about 1/3rd as much.

You can get my deviationTx config for this hex from my post on the deviationTx forums.

Update: The latest versions of deviationTx claim to have headless mode support. I haven't tested it. I also found a hardware problem in the RF module I installed to use with this aircraft. Fixing that extended the range from the roughly 150 meters that it gets with the RTF transmitter to further away than I can recognize orientation.

Without the canopy

The canopy/prop guards on this thing are huge. A common mod for the more popular V262 quad version is to take that off, and replace it with a small bit of plastic covering just the electronics.

I've done that, creating the Café Steamers version. This was done using the inner bowl from one of the Healthy Choice Café Steamers low calorie meals. The arms fit into the steam vents in the bowl. Cut a slot from the rim to the first line of vents for each arm, then a small cross in those vents to give them a bit more room, and it snaps on nice and tight. Add some red spray paint, and it's done: IMAG0140.jpg
With this on it, the hex is much more responsive. The automatic flips are nice and tight. It even has a noticeable punch out. To be fair, if you want it as a camera platform, it does tend to have a lot more wobble in the wind.

The orientation problems are also not nearly as severe, either at day without the lights or at night with them. I personally have problems dealing with just a collection of lights at a distance, but that problem is with my vision, not the hex.

And since people will want to know, I get about nine minutes of relatively gentle flight time - just flying circuits, some flips to test it, and maybe a punch out to start - in this configuration. That is with the lights on full time, but no camera attached.

My WLToys rant

If you've been reading for a while, you'll know I'm not a fan of WLToys. The issue isn't so much how their aircraft fly, since they generally fly nicely once you get them set up properly on a good transmitter, and some are clear winners. The issue is lack of quality control and customer service, and non-flight design issues.

The motor crib death on this hex is typical of my experiences with WLToys. Pieces regularly arrive dead or flaky or die before the end of the second battery, which shows that their quality control is pretty much non-existent. If you then try and get any support from them, that's equally non-existent. It generally falls to the store you bought it from - which is usually a trans-pacific discount supermarket.

The design issues - like the battery tray and the poor failure handling - are also typical of WLToys. Again, nothing that changes flight characteristics, but things that could be safety issues or create extra expense for you in the long run.


It's not a bad aerial camera when flown with a good transmitter. And with something like the Café Steamers mod, it's quite fun to fly. No, it's not a Blade 200QX, but it also doesn't cost nearly as much. I'm not sure it's worth getting the hex instead of a quad version like the V262 for less money - unless you're just interested in having a hex to fly. Since I am, I've got to give Alan a big thumbs up on this gift.