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.
Review: FlyDream 2.4GHz module and receiver (Pt 2)
PUTTING THINGS TO THE TEST
So how does the FlyDream 2.4GHz system work in practice?
Although FlyDream claim this is a Frequency-hopping system, it's more of a multi-channel DSSS one. When put on the spectrum analyzer, it is clear that the system uses only three separate groups of frequencies -- much like version 2 of Corona's DSSS sytem.
Is this really frequency hopping?
No, but it's still three times better than a single-frequency non-agile DSSS system like the FlySky.
Under test exhibited a good resistance to interference but could be blocked by strong in-band interference, even when the interfering signal did not cover the whole band.
Some of this can be put down to the receiver's inability to handle exceedingly strong signals. In fact, simply bringing the transmitter too close to the receiver (within 1-2 feet) is enough to cause the red LED on the receiver to go out and control to be lost.
In practice this may not be the issue it appears to be on the test-bench as the signal levels required to cause control loss are far greater than one would expect to encounter in "the real world". This was borne out by flight-testing in which the FlyDream performed flawlessly.
On a couple of occasions during testing, control was not restored to all channels when the transmitter was moved away again -- something strange apparently happening to the receiver software that got it somewhat confused. This was not always reproducible however, and only appeared to affect one channel so it may have been the digital servo that got confused. No such behavior was experienced in real-world testing.
A key consideration for 2.4GHz radio systems is the voltage at which the receiver stops working or resets and the voltage at which it starts working again. Early 2.4GHz systems were plagued by an inability to handle these brown-outs and very slow recovery times but the FlyDream performs well in this area.
To test the system, the receiver and one servo were connected to a variable-voltage source and the voltage slowly decreased until the bind light went out and servo movement stopped. The FlyDream continued to work right down to 2.82V and recovered almost instantly when the voltage was raised to 2.84V.
A couple of anomalies were observed during bench-testing...
Turning the receiver on before the transmitter resulted in the servos being driven hard to their limits before returning to neutral.
Clearly this could cause servo-gear damage in some cases. FlyDream advise that the new release of the product as addressed this problem.
Secondly, some slight jerkiness of servo movement was observed with slow stick deflections (although nowhere near as pronounced as with the Corona FHSS system). The effect of this is unlikely to be apparent in normal flying but if you're into very hi-speed models or hardcore 3D then it could be more of an issue. However, for that kind of flying, a budget 2.4GHz system like the FlyDream probably won't be your first choice anyway.
Like most of the low-cost 2.4GHz solutions, the failsafe on the V1.2 system I tested is inadequate for large models. FlyDream advise that they have now implemented a much better failsafe for V2.0 units, allowing the failsafe position of all channels to be set to the user's preferences.
I notice also that unlike most other 2.4GHz systems, the FlyDream transmitter module uses a slide-switch rather than a momentary-contact button to activate the bind mode. It's easy to see that this switch might accidentally be bumped if your transmitter is thrown into a flight box where other items might slide against the back of the module. No harm would be done in this case but it might leave users scratching their heads as to why they can't get any response from their model.
IS IT ANY GOOD?
First up let me say that this is one of the lowest-cost 2.4GHz module-based solutions so it's clearly not going to be in the same league as Futaba's FASST or other brand-name offerings.
On the plus side, the receiver is small and light and the construction quality seems good.
On the downside, there were some issues (mentioned above) but FlyDream claims that in the V2.0 product, the most important ones have already been addressed (if they provide a V2 sample I will check and confirm that). Hitec users will also find the transmitter antenna position to be inconvenient.
The RF side of things performs adequately and based on the testing performed to date it seems to have more than enough range (manufacturer quotes more than 1Km) but it's a little bit of a stretch to call it "frequency hopping".
The bottom line has to be: would I use it?
Yes I would. I'd be happy to use this system in any of my electric or glow-powered models, but I'd be hesitant to risk my 50cc gaser to it (or any other low-cost 2.4GHz radio for that matter) -- at least not until I've had a chance to check out the changes that have supposedly been made in the V2 product.
If you're looking for a low-cost 2.4GHz solution then the FlyDream isn't perfect but it is (at current pricing) quite good value for money and worthy of consideration, especially if the version 2 works as claimed and you can find someone selling it.Pro's:
- Small, lightweight receiver
- Triple frequency operation
- Good resilience to brownout/reboots
- Futaba module unsuitable for Hitec radios
- No useful failsafe capability
- Not *really* FHSS
- Swamps at very close range
- Very few dealers -- where do you buy?
- Product: FlyDream 2.4GHz module/receiver
- Supplied by: Fly-Dream
- Price: around US$59 for module + 1 receiver
- Overall rating: 3.5/5
Normally I buy all the products that are reviewed here but this module and receiver were offered for review by FlyDream and I accepted. FlyDream were made aware that the review would be objective and no favors would be granted. What you've just read is an honest review without any deviation from the facts.
Whenever a product that is reviewed has not been purchased with my own money, a disclosure like this will be made in the name of honesty and integrity.
Updated: 20 Sep 2012
Here's a blog that will keep you informed just what's going on behind the scenes at RC Model Reviews and also tells you a little more about myself.
23 Mar 2010
How come there's no compatibility between different brands of transmitters and receivers? Why can't you use a cheap Chinese receiver with your Futaba FASST radio?
4 Mar 2010
Since this has become a very frequently asked question, I've posted this simple guide to getting your product, or a product you're thinking of buying reviewed here at RCModelReviews
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