One of the first thoughts which is likely to go through a modeler's mind after flying an average RTF is, "how do I get more power out of this thing?"
That was my first thought after my first flight with the recently reviewed Parkflyers RC F4U Corsair. The review may be found here. I concluded that the Corsair was an exceptionally sweet-flying model with only one real drawback:
Power left a lot to be desired.
Even at a rated 1200Kv, motor performance and therefore that of the Corsair was a bit more leisurely than I've come to expect from a warbird. This isn't to say the stock setup is substandard; it's great for newer R/C pilots moving out of trainers and into more scalelike subjects and that's exactly how Parkflyers RC markets the model.
It would seem that Parkflyers RC had more advanced users in mind with the recent introduction of the Power Star 3000 upgraded motor. At a very affordable US$34.99, this isn't a mere repackaging of an existing motor but rather a custom-wound unit built to Parkflyers RC's own specifications. Along with being a perfect fit in the Corsair, it's a near bolt-on swap with Parkflyers RC's 400-class Wing Tiger, Wing Tiger EPO, Pitts, Spitfire and P51D Gunfighter, requiring little more than a bit of time spent with a soldering iron.
This will be an easy fix, so let's begin.
My Power Star 3000 arrived in its own custom display box complete with the 3mm locating nut for the Corsair's simulated variable pitch propeller along with a 3mm nylon lock nut to retain the propeller. That alone was a nice upgrade which gave the first hint of the motor's performance.
Needed for installing the motor are:
I would personally recommend changing out the female bullet connectors on the ESC while the model is apart. There's plenty of shrink wrap tubing supplied with the E-flite connectors and they mate better with the new males.
Suggested as well is some thirty-minute epoxy. The firewall is attached with little more than the kind of contact cement often found on RTF models; the epoxy is cheap insurance, indeed.
Just before the review of the Corsair was published, I took it upon myself to do a bit of detective work with the electronics to see if there was any obvious reason for the lackluster performance.
It didn't take long to find the problem.
Two of the motor's three bullet connectors were poorly soldered and hanging by only a few strands of wire.
That was a rather simple fix, consisting of a new set of E-flite 3.5mm bullet connectors and about 3" (76mm) of W.S. Deans 16-gauge silicone jacketed hookup wire on each motor lead since the original motor leads were rather short to begin with. I swapped out the female bullets on the ESC while I was at it; E-flite provides a very generous length of shrink tubing.
It seemed to perform better on the bench, but I postponed flying the Corsair once I learned that I'd be getting the Power Star 3000.
Prior to removing the original motor, I ran some simple tests of propeller RPM, power output and current draw. I wanted to see just how much power the Power Star 3000 would make in comparison to the out-of-box system once installed.
I used the fully charged original flight battery for both the before and after tests with the help of my AstroFlight Super Whattmeter and my Hobbico Digital Mini-Tach. The Super Whattmeter is powered by the flight battery, but the tachometer was in need of a couple of fresh AAA-cell alkaline batteries. RPM readings were made without the Super Whattmeter in line.
I don't use these tools often, but they're utterly invaluable at times like this.
A check of RPMs was first, followed by the power and current draw. The high readings were:
Watts divided by amps equals voltage, so the rather severe test came out to 11.08V being pumped out by the battery. Ohm's Law still reigns supreme.
I admit to being surprised at what I thought was a low RPM reading, but that Hobbico tach simply doesn't lie.
Removing the Corsair's original motor and mount was a breeze thanks to the extended length phillips screwdriver provided with the model. I took a moment to further cut down two of the mounting screws; they were protruding just a bit into the battery compartment and I'd cut them down while in the model during the write-up. Though they didn't come close to the battery, I didn't want to take a chance on a punctured battery somewhere down the line.
Reminder: If one is removing the motor for the first time, may I again suggest the use of some 30-minute epoxy to hold the firewall in place. There's little more than the familiar "RTF Mucoidial Contact Cement, Patents Pending" holding it in place. The screws themselves may be fouled by the stuff, so patience and some gentle persuasion with pliers might be in order.
Although the Power Star 3000 comes with the plastic adapter needed to attach it to the factory mount, I thought it would be faster and easier to simply remove the original motor at the adapter by loosening its 1.5mm grub screws and replacing it with the Power Star 3000. From there, it was a simple matter of reinstalling everything.
Before buttoning everything up, I did a quick check of the system to see if the new motor spun in the right direction.
Not only did I get it right, I immediately noticed the increase in speed.
And what an increase it was once the prop was back in place and with the same battery:
One should keep in mind that the actual numbers and performance are better than what tests would indicate. The tests were performed while I held the model in place on a work stand which naturally causes the propulsion system to work harder.
Now for some flying.
As always, my flight tests take place at the Coachella Valley Radio Control Club, site of the model's maiden flight.
The right-left breeze down the runway was a bit stronger than I would have normally liked, but I wanted to see how the Power Star 3000 would pull the Corsair through the wind.
Once airborne, the difference was beyond dramatic. I finally had some real power on tap for some basic aerobatics. I could now put the Corsair through larger loops, clean barrel rolls and even an Immelmann turn or two. Victory rolls were simply beautiful as I pulled the model up from low runway passes. Speed was considerably higher; it was actually faster against the wind than it had been flying with the wind prior to the motor change!
After the wind died down, in went a fresh battery and off went the Corsair with even more stunning results.
Now I was able to easily put the lightweight Corsair through its paces with more high-speed passes and smooth, easy aerobatics. The fun factor which seemed to be lacking at the lower speeds was back with a vengeance. I ran all three packs through the Corsair, each pack returning at ambient temperature.
If I had any regret, it was this: I didn't have any more batteries!
It certainly is, provided the beginner is comfortable flying the Corsair with its original motor and has some prowess with a soldering iron. Beginners should be advised that while the extra speed adds some stability, it also adds some responsiveness to the control surfaces and there's less reaction time to recover from errors. The stock radio has no provision for exponential stick adjustments, so gentle thumbs are absolutely necessary. Intermediate and advanced pilots: This simple modification is a must and a better radio is a real plus.
The Parkflyers RC Power Star 3000 motor is exactly what the doctor ordered for the Corsair and for other models using this same motor. It's a quick, simple upgrade requiring no modifications or other electronic components. Simply do some basic soldering, bolt it in and go flying. I would even go so far as to encourage beginners to order the motor ahead of time when they order their own Corsair so that they're ready to go when their skills are up to the task. Two thumbs way, way up.
My thanks go once more to Parkflyers RC for the privilege of reviewing this motor and for making the Corsair that much more enjoyable. Angela Haglund of RCGroups.com makes all of these reviews possible; she has a rather busy job, to say the least.
Thanks as always to our worldwide audience who've made RCGroups.com the number one information source for all things radio controlled. Enjoy your stay and enjoy your hot new Power Star 3000!
No minuses were noted.Last edited by DismayingObservation; Dec 02, 2013 at 09:02 PM..
|Dec 05, 2013, 12:21 PM|
The % of 20A is irrelevant.. the vital number is 66%. I hope the supplied ESC and the stock battery can cope with such an increase. Also what is the weight and Kv of the 3000 motor? I would never buy any motor where the makers and distributors refuse to supply even the most basic specs (weight, Kv, Io, Rm, max. current etc......).
|Dec 05, 2013, 04:02 PM|
Or clamn 98% efficiency.
As some brands.
As a model of these, with a pitch of only 6 and 5900 rpm, it can reach 50MPH speed.
65 MPH according to the manufacturer.
Also with a battery of 1300ma. flying up to 20 minutes.
would average about 45 watts, or 36 watts per pound.
|Dec 05, 2013, 07:45 PM|
Looks suspiciously like the DT series of hobbyking motors although the Kv isin't the same.
|Dec 05, 2013, 10:03 PM|
Your math is slightly off, Manuel (but as much as the manufacturer's!)... 6" pitch and 5900rpm gets you only 33.5 mph pitch speed.. even the touted 7340rpm only gets you 41.7mph.
|Dec 05, 2013, 10:45 PM|
Not my math.
Capable of reaching speeds up to 65 miles per hour, yet it can fly as slow as 15-20 mph.
The Tri-bladed propeller provides 25% more thrust than a standard 2 bladed prop. More prop thrust means better
low and high speed maneuverability.
Includes a 1300 mah Lipoly 11.1v volt rated at 25C that provides up to 17-20 minutes of solid run time!!
It didn't look particularly fast, topping out on downwind passes at an eyeballed top speed of maybe 50 MPH (80km/h) with a cruising speed of roughly 40 MPH (64km/h).
my calculations are 5900 son 33.55 pitch speed and 29-30 model speed.
to 7340 is 41.74 pitch speed and 37 model speed.
|Yesterday, 11:20 AM|
Gladstone, NJ. USA
Joined May 2000
I really need physical specs and rec's
Sounds like a great review. Where can I get the physical dimensions
prop, battery, and esc recommendations. I need to see if it fits my project.
Jon B in NJ. USA
|Yesterday, 11:42 AM|
Sorry Manuel... I was thinking that you had converted the numbers given in the review for Motor#1 133W/5900rpm and Motor #2 277W/7340rpm.
Flight speeds of 50mph and 65mph were mentioned.... but clearly, as you point out, with pitch speeds of only 33mph and 41mph these are impossible!
|Thread||Thread Starter||Forum||Replies||Last Post|
|Review Parkflyers RC F4U Corsair RTF Review||DismayingObservation||Electric Warbirds||7||Dec 03, 2013 11:01 PM|
|Yippee! Elfi parkflyer with spring suspension landing gear upgrades||rcastab||Parkflyers||13||Oct 25, 2013 03:40 AM|
|Review Parkflyers R/C Cessna 182 Pro Series RTF from Parkflyers.com Review||DismayingObservation||Beginner Training Area (Aircraft-Electric)||5||Aug 13, 2013 06:05 PM|
|For Sale Parkflyer plastics upgrade kit for PKZ Wildcat||RcAirplaneNoob||Aircraft - Electric - Airplanes (FS/W)||0||Feb 24, 2013 08:15 PM|