dkshema
rrProfessor
Location: Cedar Rapids, IA
| Underpowered....as I stated, the 420LF isn't exactly known in the heli world as being a screaming powerhouse of a motor. The pinion you chose may also be working against you, as well as your selection of battery and it's associated discharge rate.
I'm no electric heli genius at this point, but having operated a couple of T-Rexes for about a year, and reading as much as I can (and sorting out the BS) over on the T-Rex forum, it's pretty easy to determine that you've got a lot of variables to work with to get a good flying heli. If you have been over in the T-Rex forum, you'll discover that there are some 60,000+ posts over there. A LARGE percentage of those posts are people asking "what motor and pinion works best", and there are about as many answers as there are questions.
Only recently (within the past month or so) have any of the Align motors made people stand up and pay attention to them as serious contenders for providing anything other than average performance in the T-Rex. That motor is the Align 430L/3550KV motor. Up until that motor was introduced, the Align motors were mostly known for running HOT and not providing stellar performance.
The HOT T-Rex's that are performing very well are either running very expensive motors ($100 and up), or are running expensive motors and 4 to 6S LiPos.
The JGF 400DH was touted as providing some real punch to the T-Rex. It does work well, but by no means does it really make the T-Rex sing. The JGF 450TH is reportedly a strong motor in the T-Rex, along with the 430L/3550 from Align. The reports that I've read here on both of those motors indicate that finally, after a year of being out on the market, that a good, strong running 3S setup is finally available at a decent price.
If you also read the T-Rex forum, you'll see that a lot of the die-hards over there have invested a TON of money in trying different motor/ESC/battery combos to get a good running system. A thousand dollars invested in a T-Rex is not unusual, to get real performance, it is the norm, and only a start at that.
You've tried one brushless motor and one pinion in the EP 400. The motor you tried as I stated earlier, didn't really even light up the T-Rex, so I wouldn't expect it to make a stellar performer out of the EP 400. One pinion has also been tried in your setup. Again, the T-Rex forum tends to indicate that those who have been very successful with the T-Rex have spent a LOT of time mixing and matching pinions to their motors.
Along the way, the T-Rex crowd has done a bunch of tweaking to the basic airframe to get superior performance. The "Doctor Dremel" mod to remove almost all "excess" plastic to get the thing light enough to fly well was one of the first mods (go look at the early posts that talked about how the T-Rex was just too heavy to fly or perform well). That was followed by a whole boatload of DIY CCPM hacks to improve the control system, and further reduce weight. Next, there was the addition of some more precision aftermarket parts to improve performance even more. Then CF blades were introduced to improve performance yet again. Homemade CF frames, homemade and aftermarket upgrades abound now for the T-Rex. That's not by accident. All that tinkering was and still is necessary.
Go take a serious look at the T-Rex forum. See how many "tracking problem" posts there are. Or how many "serious tail wag issues" posts there are. Or maybe look into the number of times the TR belt drive has been a problem. Read about the poor fit of the canopy on most models, so severe that the canopy just plain interferes with the control system. Read the endless posts about ball links being too tight, or too loose. Are the original purple links OK, or the upgraded gray ones, or the "new" purple links, and finally the new black links. They're all still tight. Or the posts about the skid cross struts breaking all the time. Maybe you haven't seen the repetitive posts about all versions of the Align swashplates coming apart in flight. Or the uniball getting bound up in the swash. Then there are the posts about poor CNC work on some of the Align upgrades -- heads that aren't made right, flybars that don't fit the new flybar seesaw and control system, new CNC TR hubs from Align that explode in flight. Plastic parts whose molds are bad, or the quality just isn't there. Cheap screws. Motor end-bells that fall off. New dual-fork tail rotor bellcranks that are too tight and don't work properly.
It hasn't been all sunshine and lollipops in T-Rex land this past year. Even today, there are still a bunch of rough spots in the T-Rex world. The T-Rex road is getting smoother, but you still might need a 4WD to navigate it from time to time.
In spite of all of those troubles, the T-Rex has taken the RC Heli world by storm. The main reason is that Align had a pretty shrewd market strategy -- introduce a dirt cheap electric heli kit that showed promise, then sell spares for dirt cheap, only package the spares such that you never could just buy what you really needed or wanted. There are a lot of parts in people's spares boxes that will probably never be used, but only because you had to buy them to get the part you really needed (pitch mixing levers, anyone?). Align then started trickling out upgrades to fix known deficiencies in the kits. They're still doing it.
Prior to the debut of the T-Rex, the Shogun/Zoom/Zap/Dolphin was "the" micro heli to own. Go read THAT forum here and see what people have had to put up with to get a decent flying micro heli. Again, spending a thousand dollars on a single Shogun is chicken feed compared to what it actually took some people to get a good performer. There were at least three attempts that I'm aware of to get the stock shaft driven TR to work reliably. There are at least two belt-drive upgrades on the market that actually cost more to buy than it did to buy the Shogun kit in the first place.
In the end, I suspect that like the Shogun (first real contender for "super" micro heli performance), and the T-Rex (current champion of the micro heli performers), the EP 400 is going to take a small army of dedicated "tuners" out there to find the right motor/pinion/ESC/battery combination to make this heli perform up to its potential. It will be the people with the time, the ingenuity, and the $$$ resources who will crack this nut.
I have some time, I have the ingenuity. At the moment, the $$$ resources need to be managed among food, shelter, two teen-agers, a five year old, and my wife. I plan to pick up an EP 400 as soon as I can, and see what it takes to make one of them tick, and tick well.
As I said earlier, if you don't like your EP 400, send it to me, I'll put it out of your misery. I don't necessarily have deep pockets to spend endless amounts of $$$ on it, but I'm willing to learn what others have tried successfully and apply it, while doing a bit of my own tuning and experimentation. And I might just end up with another fine flying heli.
True, it could turn out that the EP 400 is a dog. But it's going to take more than one person with one motor and one pinion to convince me of that.
A short history lesson here:
When I first started flying RC planes as a kid just out of high school, with my first "real" job, I used to save all my receipts from hobby related stuff that I purchased. After about two years, I had this sudden urge to take out all those receipts, add up the numbers, and see what I had spent so far on my hobby. When the numbers rolled out on the paper (before the advent of the hand-held pocket calculator), I scared myself with the bottom line. There was no way I could have spent that much in two years or so! But I did. Now, the choice was to give up this hobby because of the expense, or hang in there.
Thirty-five years later, I look back at that day, and my decision to stay the course. I've spent countless $$$ since on planes, helis, parts, motors, glue, wheels, accessories, radios...and it has all been worth it. I've had fun, I've learned a TON, and I've taught a lot of people to fly along the way, and made countless friends. The money spent on this hobby has no match to the countless hours of enjoyment, relaxation, challenge, satisfaction, and friends made along the way. I'm now passing the fun on to my kids. I hope they take up the baton and run with it.
The moral is that it's not the money invested in this hobby that's important. It's the return on investment that you get from that money.
Dave |
