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Apr 18, 2016, 08:59 PM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by cccpull
Bangood USA warehouse has the BNF for $99.99 + shipping and RTF 139.99 + shipping and 5% off this month. Their shipping is very reasonable.
Yes, you are right. Sometimes when I try the PNP at BG, the price is $99. Other times it seems to be $139.99. Today it's $99.99. Yesterday it was $139.99.
Don
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Apr 19, 2016, 08:00 AM
Registered User
I had the same situation happen to me, until I realized the lower price would occur when in the US warehouse instead of the main/home Bangood site. Nevertheless, it was just a heads up on the price, since I had been checking this model out for a while.

BTW, this is no "mini-review", it's quite detailed and very nicely done. I'm always appreciative of reviews, it's fun, but it's also a lot of work.
Apr 20, 2016, 09:20 AM
Registered User
Thanks for the review hifinsword and I don't think there was too much that was "mini" about it. This came at a good time as cccpull sent me the link for this plane and I ordered it. It should be arriving any day now. According to the info mine came from the USA warehouse. I ordered the PNP kit. I was surprised that there was a lot more assembly to do do this kit than I thought-which is ok. I was just under the impression that it was pretty much but the battery the receiver in and the wings on and you would be ready. Thanks again for the time and effort. With this info, can't wait for it to get here.
Apr 20, 2016, 11:11 AM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by cccpull
I had the same situation happen to me, until I realized the lower price would occur when in the US warehouse instead of the main/home Bangood site. Nevertheless, it was just a heads up on the price, since I had been checking this model out for a while.

BTW, this is no "mini-review", it's quite detailed and very nicely done. I'm always appreciative of reviews, it's fun, but it's also a lot of work.
Quote:
Originally Posted by Tman00
Thanks for the review hifinsword and I don't think there was too much that was "mini" about it. This came at a good time as cccpull sent me the link for this plane and I ordered it. It should be arriving any day now. According to the info mine came from the USA warehouse. I ordered the PNP kit. I was surprised that there was a lot more assembly to do do this kit than I thought-which is ok. I was just under the impression that it was pretty much but the battery the receiver in and the wings on and you would be ready. Thanks again for the time and effort. With this info, can't wait for it to get here.
Thanks for the comments guys. I revised the first paragraph of post 1 and made this a discussion thread for the plane. I really like the plane and think it will be a good plane for anyone flying it. It really does handle well. That's including moderately windy days, even without a Stabilizer. I still have to pull the motor and ESC to finish the writeup. Any substitutions for parts that workout well, will go into the first page, or linked on the first page so hopefully you don't have to go searching the thread for such things.
Don
Last edited by hifinsword; Apr 27, 2016 at 03:46 AM.
Apr 21, 2016, 09:58 AM
Registered User
There was a package waiting on my door step when I got home last night. My new FMS Super EZ! The only thing I got to do last night was to open it up and check to make sure there was no damage. It was all good! Unfortunately I have to go out of town tomorrow and won't be back until mid week-so no putting it together until later. Feel like a kid at Christmas time.
Apr 21, 2016, 03:43 PM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by Tman00
There was a package waiting on my door step when I got home last night. My new FMS Super EZ! The only thing I got to do last night was to open it up and check to make sure there was no damage. It was all good! Unfortunately I have to go out of town tomorrow and won't be back until mid week-so no putting it together until later. Feel like a kid at Christmas time.
Yeah. I feel like that even if it's only a prop that just came in. Feels great!
Hope you can get to it soon.
Don
Apr 22, 2016, 03:29 PM
Time For Me To Fly!
fastmax's Avatar
Very nice review and thread! Thanks for sharing. I may have to give one of these a try in the future.
Latest blog entry: Hobbymate X130 Build & Review
Apr 24, 2016, 04:54 AM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by fastmax
Very nice review and thread! Thanks for sharing. I may have to give one of these a try in the future.
Thanks. I hope it helps.
Don
Apr 24, 2016, 04:55 AM
Blue Skies
hifinsword's Avatar

Measured CG versus other CGs


1. GENERAL CG DISCUSSION
I'm no engineer or aerodynamist. I'm sure there are technical differences for the different Center of Gravity (CG) terms that are tossed about. But to simplify this discussion, I am going to use the following terms - CG range, ideal CG, designed CG, published CG and measured CG.

What is the CG in an airplane? We'll leave helicopters and multirotors out of this discussion. In real airplanes, "CG range" is usually discussed with the terms forward and aft CG limits used. It is a range of measurements that give you the best flight characteristics for the mission or phase of flight you are flying. The CG point moves as passengers embark or disembark, fuel is burned or received, cargo taken on or discharged, weapons released, etc.

In model airplanes with internal combustion (IC) engines, CG changes are usually limited by weight changes due to things like the fuel burned or a "candy drop mission. With electric-powered airplanes it's usually the "candy drop" mission that would change your CG. You have to take into account any fuel burned or candy dropped so that your CG range stays within the "CG range" fore and aft limits.

The "ideal CG" is that CG which achieves hands-off straight and level flight with no trim to the control surfaces.
You don't pick a CG point and make it balance there. You balance your plane and find out where that point is. The recommended CG is a good starting point, not the ending point.
Airplanes have a "designed CG". The engineers designing the airplane take into account what they want to achieve and design the airplane around those parameters. They know mathmatically where the CG should be based on their design. They design around a "datum line". You won't usually find it in the RC model's stats. A common substitute for it is the horizontal stabilizer.

"Measured CG" is where your airplane's CG measures in a balanced condition. The horizontal stabilizer of your airplane should be level.

Hopefully your measured CG agrees with the ideal CG. In fact the measured CG is your ideal CG if you can achieve balanced flight with it. Assuming your airplane does not have a twisted fuselage or wings, problems with angles of incidence, etc., your airplane should perform its best once you have set it up with a CG that gives you a balanced and level airplane.

The "published CG" is what the manufacturer of model airplanes have published as the CG at which the model should be flown. Too often we chase the "published CG" to achieve a balanced airplane. That is not needed when the airplane balances out of the box at a different CG than published. Before you add weight to the nose or tail of your airplane to achieve the published CG, fly it as it balances with a level horizontal stabilizer, whatever that CG may be.

2. TO MEASURE CG UPSIDE DOWN OR NOT, GEAR UP OR DOWN? THAT IS THE QUESTION.
There is way too much discussion about how to measure CG, be it upside down or a normal attitude, with "gear retracted" (gear up) or "gear down" (gear lowered). IT DOES NOT MATTER!

The upside down or a normal attitude when measuring CG is all based on what is the easiest way to measure CG.

The term "gear up" when flying real airplanes means in the wheel well, not "up" in the air with your airplane upside down. Likewise, "gear down" means "down and locked for landing", NOT down from a vertical position in the air while in an upside down attitude.

Balancing an airplane is easier if the center of mass is below the point the airplane is being held up by. For low wing airplanes that means upside down. For high wing airplanes that means a normal attitude. Use whatever works for you.

Try holding a small high-wing plane upside down, loosely by the wing tips. It will try to rotate to the normal position. That's where the center of mass balances most easily. The opposite is true for low-wing planes.

As for gear being retracted or lowered, it's also up to you. Since most of the flight for most of us, will be with the gear retracted, that will be what you are trying to measure - the CG that your airplane will be experiencing for most of the flight. If you plan to fly only touch & go's (T&Gs) and want to make sure your CG is at an ideal spot, measure with wheels down. It's your choice.

3. THE FMS SUPER EZ
This is a long way of getting to the FMS Super EZ's published CG of 60mm. I was able to fly with a balanced airplane at a measured CG of 72mm, and then 76mm with the stock battery. The more the airplane was nose-heavy, (CG at 72mm) the less it was able to perform. A CG of 76mm was much better at performing loops. A nose-heavy CG induces drag that is reduced at a more neutral CG of 76mm. Without the extra drag created by a nose-heavy attitude, the power is available to provide the thrust and lift needed for loops. A more neutral CG allows a higher performance level.

Adding weight just to achieve the published CG of 60mm did not make any sense for me, when it was obvious adding weight to an already slightly nose-heavy plane would only make it more nose-heavy. Measure where your airplane balances and fly the CG that gives you a balanced airplane, whatever that CG comes out to be.
Don
Last edited by hifinsword; Aug 24, 2016 at 05:09 AM.
Apr 24, 2016, 07:55 AM
Blue Skies
hifinsword's Avatar

My CG machine


I decided to go hi-tech purchasing a CG measuring machine. The fingertip method just wasn't working for me. Planes kept falling off as soon as I let go with the other fingers.

But my RC budget was a little low on funds and I didn't want to sell a plane to finance it. So this is what I ended up with. And it works well. The only mod I anticipate is some foam padding on the tips so it doesn't leave an impression on the foam.
Don
Apr 24, 2016, 05:58 PM
Blue Skies
hifinsword's Avatar

CG at 82mm 1300mAh, CG at 77mm 1800mAh batt


I decided to test the aft limits of the CG today. My first flight was with the OEM 1300mAh batt. I set it to a CG of 82mm. Today's flight reminded me that less than the recommended aileron throws are definitely needed for a beginner. I flew with some turbulent, but not strong wind. I was low and the wind was moving the EZ around some in some spots on the field probably because of a burble coming off the trees. It was one of those pull up, , whoa, , push down, , come right, , now left!! SAVED IT! WHEW!! moments.

Without any expo or reduced rates, it got touchy for a few seconds. But most of the flight time was up high and uneventful.

I think a CG of 82mm is close to the aft CG limit with the lighter 1300mAh batt. The lighter batt didn't move the CG forward as much as the heavier 1800mAh batt did. That was even though the heavier batt was further back than the OEM 1300mAh batt. The plane's CG moves forward with batteries in place.

I put the heavier 1800mAh LiPo in as far back as possible without going into the Radio bay. It gives a CG of 77mm. You can see from the pictures where the batt falls on the battery tray.

Performance was similar to the second day, after the first day of flights reported earlier. Big loops were fine. Some forward stick was required to maintain inverted flight. I would call the forward stick medium as opposed to light force with the CG further forward with a CG in the low to mid 70mm range. Straight and level flight was no problem at 50-60% throttle. Gliding in for a landing with zero throttle was surprising. The more aft CG seems to give a higher angle of attack in the wind, causing more lift when trying to dive to a landing with some wind on the nose.
Don
Last edited by hifinsword; Aug 24, 2016 at 05:13 AM.
Apr 24, 2016, 09:38 PM
Registered User
Excellent resource you have created here. If possible, please also test the cg with 3s 2200mah packs.
Apr 25, 2016, 02:58 AM
Registered User
TechTronic9000's Avatar
Looking forward to the maiden flight
Latest blog entry: VolantexRC V767-1 "Firstar"...
Apr 25, 2016, 08:48 AM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by Lentar
Excellent resource you have created here. If possible, please also test the cg with 3s 2200mah packs.
I'm getting ready to go out to fly later this morning. I have a 2200mAh 3S LiPo I was planning to use in my PZ Corsair but maybe it'll end up in my EZ.

I converted the plane over to a Spektrum system this morning and took out the FS system. That will give me THR CUT, a nice safety feature, an automatic timer, and the ability to change throws and exponential to my personal taste. My Lemon receiver also gives me the ability to turn on or off a 3-axis gyro rate stabilizer, and vary the gain, either individually on the ground for each control surface, or all of them collectively inflight. Post flight report to follow.
Don
Last edited by hifinsword; Jan 05, 2017 at 08:12 AM.
Apr 25, 2016, 08:49 AM
Blue Skies
hifinsword's Avatar
Quote:
Originally Posted by TechTronic9000
Looking forward to the maiden flight
Good luck TT. Is it a PNP or RTF?
Don


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