|Weight:||7.9oz / 225g|
|Length:||13.77in. / 350mm|
|Flying distance:||11.8in. / 300 M|
|Receiver:||4 channel with gyro|
|Battery:||1150 mAh 3.7v LiPo|
|Blade Diameter:||13.77 in. / 350mm|
|Typical Flight Duration:||6 – 9 minutes|
I suppose a good way to start this review would be ask oneself how a helicopter can be offered for about $60 with free shipping and be worth your effort. I gave this a good thought before starting this review and immediately removed the MJX F-28 from the well-packaged shipping box, charged the battery and started flying. I had one simple goal for this review and that was to makes the difference in the F-28 between an RC hobbyist product and a toy.
I can assure you with no hesitation this is not a toy. It is a well-built coaxial helicopter with a metal frame that, after repeated flights, did not show signs of wear, loosening screws and bolts, or poorly milled gears with an incorrect gear mesh. I can honestly say that I learned to become a better rotorcraft flier using the MJX F-28, and I am pleased I took the time to follow through with the review.
For those of you wanting to try rotor flying, this is a great way to get started. The F-28 package is not 2.4 GHz, but includes everything you need to fly: The bird, 3.7v 1150 mAh battery, 110v charger, extra blades, and most importantly, a programmable transmitter. The canopy is nicely painted and comes in blue or red. The landing gear is aluminum with the typical FM antennae wrapped around one gear. While I was impressed overall with everything, it was the transmitter that stood out. I will detail more later, but rest assured that no toy has a programmable transmitter with an easily readable backlit LCD screen.
The F-28 is an RTF, and all you need to do is install the antennae. Mine, unfortunately, did not make it in the shipping process. It had somehow slipped out of the box. I was offered another, but I had plenty of FM transmitter antennae, so I quickly found one and installed it with no problem.
RTF F-28 Includes:
The screen on the transmitter provides some feedback both on the ground and in the air. I am not one to take my eyes off the aircraft so the movement indicators are more for ground testing. On the screen you see a height and direction indicator, channel indicator (three frequencies are included in transmitter), voltage in both numeric and symbolic, signal indicator, and a throttle position indicator. The screen also includes a backlit option.
The flow chart for setup includes the ability to set the sticks to mode 1 or mode 2. Rudder, elevator, aileron and throttle are programmable with settings for end point, expo and servo reversing. The endpoints use presets, but the expo is fully adjustable. The throttle is adjustable so you can reduce the available power to the rotors. All of these settings are very useful for early flights to reduce overcorrection and being too strong on the sticks. I did dial these all down until I became comfortable with the F-28. Keep in mind that if you fly indoors with no wind the reduced end points will work great, but if you move outdoors you might find the inability to overcome the wind and see the need for more control input authority.
Lets get right to it. The first thing I noticed was that the F-28 was quiet. While you hear some gear mesh, you do not hear gears grinding. The blades were balanced right out or the box, and I immediately flew to a hover, but with some movement, so I invested some time in understanding the transmitter.
The instructions that come with the model are in Chinese, but the website provides the interpreted instruction that are easy to follow.
The tail is coordinated with the gyroscope so as you increase the trim to hold the tail steady, you are also increasing the gyro response. This is the only setting that has to be reset every time you fly. I just powered up and bumped the trim to 7 or 8 as a setting and in a no wind condition I could almost fly hands off in a hover.
I did notice that as you input directional control, the F-28 will respond by dropping its altitude slightly. I was easily able to increase the throttle which I thought was perfectly set for my thumb, and kept the altitude steady.
I did not find any issues with my F-28. It flew very well, was responsive to inputs, holds a hover nicely, and I do believe I have many more flights left with no need to replace anything. After at least 20 flights I have little wear on the gears and I can see a slight amount of lubrication evident.
Arming the ESC on the F-28 is, from what I experienced, just a little different than other ESC arming procedures in that once you move the stick to full throttle, you still have to move the stick back to zero throttle and then up to the mid point and back. You can see the headlight locks on fully (not blinking) and the transmitter reflects the ESC is armed symbolically on the LCD screen.
The battery is a perfect fit in a holding carrier under the fuselage, and I thought a nice touch in the design is the fact that the female plug is actually housed in the fuselage. In other words, you do not have to fumble with two plug ends; simply plug the male end into the fuselage. The F-28 uses two different blades for each rotor. The extra set is actually four blades.
As the battery begins to diminish, the F-28 will require more and more throttle input. It is easy to tell your flight is coming to an end. I did not experience any quick losses of power.
After flights I always felt the battery, drive shaft and motors for heat build up, and I did not find any of these to be hot: slightly warm at best.
One thing that some coxial helicopters can do is simply tip over on throttle up. The F-28 was solid from takeoff to hover to landing. I also thought the stability and stance of the landing mains was good with little tipping on landings.
The F-28 is all about beginner flights. The ability to dial back the end points on the transmitter and turn down the throttle inputs is worth a lot with regard to learning to fly a helicopter. The tail is responsive to the trim inputs, and when you have it set, the tail pretty much sits still. None hold perfectly, but the F-28 was capable of sitting tight and holding a hover. This is extremely important for learning to fly.
Overall, I enjoyed this helicopter and still do think it has a lot of flying time ahead. I thought the flight times were reasonable and what one would expect. I would order an extra battery. I cannot completely attest to the durability of the F-28, as I never crashed the helicopter. I learned to fly on a rotor-powered helicopter, and while I was a little rusty, my thumbs remembered what they needed to do after a few flights. I did bounce the blades into objects a few times, and I was pleased they were not brittle at all. I have flown other helicopters that would shatter if they had even a slight impact. The landing gear is durable and can stand a bounce without deforming.
The battery is a 3.7 volt LiPo holding 1150 mAh of power so you will get 6 – 8 minutes flights no problem. It took generally about three hours to charge the battery using the supplied charger. I was able to use my own charger and get a charge in about an hour.
There are a few design points I want to mention as excellent:
For your information:
|Jan 20, 2012, 07:23 PM|
Man, what a NICE transmitter! Full sized, digital trims and that cool display.
Does it merely respond to stick input or does it have a telemetry link? I doubt the latter due to the cost, but what a cool selling point that would be if it were true.
|Jan 21, 2012, 02:58 AM|
I have owned an F28 - twice!
I bought it and flew it. Found it did not suit my flying style. Sold it. The owner flew it for a while, broke it, tried to fix it, made it worse, put new parts into it, still no go, sold it back to me cheap. I tore it down and found he had lost all the bearings out of it!
Anyways - my experiences:
4ch with solid MJX build quality
Configurable servo rates and endpoints
Digital trims work well
Mode 1 (actually mode 4) and mode 2 switcheable
Stable and easy flier
Only need 4 AA batteries
3.7V system is underpowered and has short flight times when flown hard - a higher performance battery would likely help some
Tx programming button and wheel are very imprecise
LCD display is only useful for configuring, not for flying (not really a con)
If this fits your needs, that $62 price at Banggood is actually pretty good. Based on my experience with the F28, I would say the stable hover, and predictable movement, makes it good for a novice that wants a larger heli. Performance minded fliers will want more power and flight time.
This was my fleet at the time: T23 (modded it), T34 (sold it), F28 (got it again), T38 (modded it)
|Jan 25, 2012, 05:22 AM|
United Kingdom, Coventry
Joined Jan 2012
I am new to RC helicopters, having received a cheap micro heli for Christmas, which is great for indoor flying and I really like it. I would like to buy a larger model, and have a shortlist of the T23, T34, F28 or Skyking. As you have owned three of these four, I would really appreciate your advice for a novice (or indeed from any others with experience)
I will probably not mod it, simply fly it out of the box and adjust settings to enjoy when I can find the time.
|Jan 25, 2012, 07:15 AM|
Joined Nov 2005
My experience was a slight breeze was all it took to cause problem with movement. I mention in the article that if you do fly outdoors you need to make sure your control inputs ate maxed out to get it to fight the wind. When dialed back, I noticed at time into the wind I could not make any headway.
|Jan 25, 2012, 06:13 PM|
Good luck and have fun!
|Jan 25, 2012, 06:58 PM|
T23 - The T23 is 24" long and is a 3ch with elevator servo rather than rear tail motor. The transmitter is configurable. It is too big for indoors unless you have a lot of room. Hovering in my family room, this beast really makes it own wind which then effects its stability. With only 3ch's, control is limited, which means you can't get away from a wall when you need to. Outdoors it needs the tx settings, fwd trims, and servo arms cranked up, and is challenging but fun. Indoors-too big. Outdoors-light breeze only.
T34 - The T34 is about 20" long, has the horizontal tail motor for fwd/rev and also has the configurable tx. It is slow, predictable, and easy to fly, but again, the size and 3ch controls limit indoor to careful hovering around. Indoors-too big. Outdoors-totally calm only.
F28 - The F28 is about 14" long, proper 4ch, super tough blades, good size for indoors. Outdoors, with mode 2 practice, tx settings and fwd trims maxed out it, can handle a very light breeze, if you can. Also see my experiences in post #5.
Summary: Indoors-good. Outdoors-mostly calm only.
The Skyking is likely to fly like a bigger version of the T34.
Big doesn't automatically mean outdoor capable, just bigger crashes.
Most coaxials are very limited in outdoor ability, especially stock. Even one that can handle some wind, such as the X350, requires practice and parts.
Maybe check out some of the more agressive fixed pitch micros as a next step.
|Jan 26, 2012, 12:24 PM|
And I agree that the F28 could be a good, inexpensive compromise if you prefer to not yet jump into a mode 2 fixed pitch, which many here will recommend as a next step.
Give yourself extra room until you get used to the controls. Start by flying it just like your 3ch, then add in the aileron movements.
I found the F28 too underpowered to suit my flying style but is very durable and easy to fly.
It will come in mode 1 (actually mode 4), which is the same controls as your 3ch, but with aileron for side-flying added to the left stick. Once you have the hang of it, go into the tx and increase the settings for more speed and faster response.
Then, when you want to move up to a mode 2 heli, you can easily switch your F28 tx to mode 2, which, with all cyclics on the right stick, makes faster maneuvers easier.
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