Model-Load, doing better than Spektrum's Model-Match

Your Reviewer

My Credentials
So who's doing this reviewing then?

Well I've been building and flying or driving radio controlled models for over 40 years and during that time I like to think I've built up a reasonable amount of knowledge.

I'm also a qualified electronics engineer who has worked in radio frequency, analog, digital systems and software for more than three decades. In fact I designed and built my first RC set back in 1969.

For the past nine years I've also been involved in the design and manufacture of some rather sophisticated engine technology and UAV flight control systems.

So, chances are I've been there, done that and have a huge pile of tee shirts to prove it.

Right now I'm heavily into 3D flying and enjoy all aspects of the RC hobby. I may be old but I don't feel it.

In the Pipeline

Here's just a little bit of what's to come on this site...

RC explained: Demystifying terms such as PCM, PPM dual conversion, single conversion, full-range etc., this feature will explain it all.

Cheap Chinese Engines: Just how good are those cheap Chinese glow and gas engines that sell for half the price of their "brand-name" equivalent? I put several to the test.

Build your own radio gear?: Back in the old days, building your own RC gear was not uncommon and now the arrival of 2.4GHz has made it practical again.

Better than Model-Match: Model-Load

LET'S AVOID A PATENT ON THIS ONE

Dated: 30 Apr 2010

There can be very few RC model fliers who, at one time or another, hasn't lost a plane to the effects of inadvertently using the wrong model memory.

Computer radios are great and they allow the various model-specific setting, such as trim, servo directions, throws, mixes, etc, to be stored in memory and recalled for each different aircraft in your hangar. The only problem is that it's often far too easy to take off with the wrong memory selected.

To avoid this situation, Spektrum were smart enough to develop and implement a system called Model-Match. This ensures that you can't accidentally fly the a model while having the wrong memory selected.

There can be little doubt that this has saved many models from destruction.

Unfortunately for the model-flying public, Spektrum chose to patent this innovation, which means that other manufacturers, such as Futaba, JR, Hitec etc, can't include it in their own equipment.

However, thanks to the computer power and 2-way radio links that are now becoming commonplace in 2.4GHz radio systems, there is a better way and I'm going to tell you how it should be done.

How does Model-Load work?

When a system fitted with Model-Load is used, the following would happen:

The receiver broadcasts its unique receiver ID number to the transmitter.
The transmitter searches its memory for a matching ID which is associated with a model-memory
If a matching model-memory is found, the transmitter automatically switches to that model-memory and begins transmitting as normal

From a user's perspective, you turn on your model and transmitter then, as if by magic, the correct model is selected and you're ready to fly.

Even systems currently fitted with Model Match require you to manually select the correct model -- a process involving multiple button presses and messing around. Model-Load completely automates the process, making things simpler, easier and safer.

Best of all...

The best thing of all however, is that this is not patented and therefore is a system that anyone can implement on their native 2.4GHz radio system.

By publishing this article and detailing the way it works, (henceforth considered "prior art"), nobody can subsequently come along and file a patent that would (like Model Match) prevent other manufacturers from of using it.

But what if...

There are a few "what if's" to be considered when implementing such a system however.

Firstly, some electric models and helicopter gyros don't like being powered up without a valid signal on the throttle or rudder channels.

This is simple to solve. The receivers used in Model-Load systems would have two failsafe settings. The first would be the normal failsafe and represent the appropriate settings in the event that signal is lost after the system is powered up. The second failsafe would be the "startup" settings that would be out put when the receiver is first turned on without any transmitter signal being present.

These "startup" failsafes would ensure that you'd get proper gyro initialization and that your electric speed controller would properly arm.

What if you accidentally turn the radio on with the throttle at a high setting when using an electric model -- after all, the speed controller may have been armed by the second failsafe described above and thus the model could burst into life with life-threatening consequences?

That's simple too. The throttle stick would remain inactive on the transmitter until it was moved to the full position, then back to to the low position after the radio was turned on. This would be an automatic low-throttle lock.

What if you'd left another model on (perhaps in the back of your car) so that the transmitter was already initialized for the wrong memory setting?

Simple, when you turned on the receiver, it would broadcast its unique ID and the transmitter, seeing that this was now a second active receiver, would signal an alarm to indicate that two receivers were currently active.

What do you think?

Hopefully, we'll see manufacturers taking advantage of this idea and going one better than Spektrum. While I can understand the commercial expediency in Spektrum patenting their Model-Match system, I think it was a bad move for safety within the hobby, hence my goal to ensure that we have something even better that all manufacturers can deliver without nasty legal battles.