Hobbyking Durafly Zephyr V70 EDF Glider - Page 11 - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Jun 16, 2012, 10:27 PM
Commercial UAV Pilot
Originally Posted by ozzi supercub
Scott you have to understand that because this model is so different to anything available currently, questions will be raised. I'm guessing most guys here when they see a new model start thinking about how to mod it to try and improve it. Sometimes it works and sometimes it doesnt. EDF guys are the worst of the lot Its always 4S, 5S, bigger lipos, more speed lol
It only seems fair that if your prepared to accept people singing its praises before they've even flown one or even seen one fly then you should also be prepared to accept people asking legitimate questions.
We were discussing the Zephyr at my field this morning and I was wondering how the V-tail and the servos would handle being blasted by a 200+ kmh wind blast from a hot EDF system. I guess we'll find out when the the next batch arrives
Hey, I don't mind questions at all.....I already said...by all means, wait for the reviews to come out.
Sign up now
to remove ads between posts
Jun 16, 2012, 11:28 PM
The Earth got in the way!
kuczy's Avatar
^Will do... and like I said if it does perform like you say I'll try to get one to take to E-jets International for the big boys to see.
Jun 17, 2012, 12:23 AM
I'm wondering how it flies as compared to the Blaze or the HK Dynamic S.
Any of you buyers have one by chance?
If you had one of those would you want the V70?
Last edited by IFlyRCs; Jun 17, 2012 at 12:28 AM.
Jun 17, 2012, 09:52 AM
Registered User
karoliinasalmin's Avatar
Originally Posted by Turbofans
The battery/ESC/receiver compartment looks like its going to be a tight fit with big 3300-4000 packs. I noticed two cooling intakes on the nose, but I did not see any cooling exhaust. Maybe there is an exhaust hole just in front of the fan, but again, did not see one because there was no picture at that angle. A 4S pack may produce too much heat. Does anyone know if this plane has cooling exhaust?
The battery pack heat is not dependent on the cell count, but on how many amps you draw from it. For example, the 5000 mAh 6S battery is cool after a flight with my X8 because my amp draw is around 7 amps (without much cooling) during the course of the flight instead of something 70+ amps. The higher the mAh rating of the battery, the more amps one can get before the battery gets hot. If the battery gets hot anyway, it is indication of possible damage for the battery. I have ruined some batteries in EDF jets, exceeded the amp draw of the battery capacity + C-rating. Actually, the higher the cell count on the battery, the less amps are needed for the same power, and therefore the cooler the battery pack (and the motor) will be (for the same power). The heat itself or the thrust or the power has nothing to do with the cell count but power is amps * voltage and if you don't raise voltage, you will need insane amount of amps to get sufficient power out of the fan. Unless of course you are sufficient with the reduced power of going lower cell count.

Imaginary example:
14.4 V * 70 A = 1008 W
11.1 V * 70 A = 777 W
to get 1008 W with 3S you need: 1008/11.1 = 90 amps
1008 W with 90 amps makes the 3S battery much hotter than the 70 amps at 1008 W. Or if you want to save battery and motor, then 6S is even better: You need only 45 amps to deliver the same amount of watts that took 90 amps with 3S. The difference is that the 3S system killed the battery and burned the motor, but the 6S system runs happily all day long.

One could then think that why not to make 100S system? 100S system would be very good except that it requires very low KV rating for the motor to have the rotational speed of the fan in the desired range. The low KV rating is simple to do but it is very difficult to do it in a small space. Therefore low KV motors have thinner wire if they are the same size as the higher KV motors, and the higher KV motors therefore withstand more amps and thus will deliver more power which leads to the requirement to use lower cell count. If one would be designing a full size electric aircraft or full size electric car, then it would be very beneficial to up the cell count to very high, but for RC plane it is reasonable to use e.g. as low as the 3-12S systems for practical reasons to be able to use lightweight and inexpensive motors (and batteries and controllers). But the "cooling may be too insufficient for 4S" with subsequent consideration of using 3S, is inherently false assumption. The very basics of high school physics is enough to know this.

Since the fan design is not variable but is what you get from the shop, they are designed for certain rotational speed. To get enough power you have to somehow get the fan to rotate fast enough. And this can only typically happen by adjusting the cell count of the battery. 3S system without changing the fan obviously, will lead to slower rotation speed and less thrust and less power. In a typical HK 70mm ducted fan, the thrust typically obtained with 3S is very poor and it will be difficult to even launch the model. A more higher pitched fan, like the 70 mm ChangeSun 10 blade fan may produce same wattage with lower cell count, but with higher amp draw.

If the fan and the battery cell count is kept constant, then only the mAh and C-rating of the battery can be varied. The higher the mAh capacity and the higher the C-rating of the battery, the cooler it stays. And the higher the C-rating the more expensive (and heavier) the battery will be. It is much more economical (and beneficial) to up the mAh capacity than the C-rating. E.g. 4000 mAh 4S is much better than 2200 mAh, and the 4000 mAh battery stays much cooler than the 2200 mAh one (with the same amp draw and power/thrust with the fan that was unchanged in this example).
Last edited by karoliinasalmin; Jun 17, 2012 at 10:10 AM.
Jun 17, 2012, 11:07 AM
Suspended Account
anybody received his zephyr yet? Id like some pictures of the box
Jun 17, 2012, 02:27 PM
Ask me about my FPV addiction
Ugrd's Avatar
My fathers nor mine has arrived yet im guessing by Friday-Saturday we will get ours. They have shipped them out though.

Jun 17, 2012, 03:02 PM
Suspended Account
Please post some pictures when and if you can.
Jun 17, 2012, 06:31 PM
sssss18's Avatar
think mine will hit the UK about Tuesday. then its up to the customs gods to release before next weekend.
Jun 18, 2012, 08:21 AM
Geez That's A Big Fly
Banjofrog's Avatar
Mine was shipped Saturday, but it may go via Sydney which seems to be the long way so I may see it Friday maybe.......

Jun 19, 2012, 04:09 AM
Grand-Duchy of Luxembourg
Aender69's Avatar
Originally Posted by IFlyRCs
I'm wondering how it flies as compared to the Blaze or the HK Dynamic S.
Any of you buyers have one by chance?
If you had one of those would you want the V70?
Bernard from bungymania.com has just put online a review of the Dynamic S.

The flight envelope is roughly the same as my Robbe Parabolic (without V-tail however). With the right (light) setup the Parabolic is reasonably fast, but still likes to thermal on strong days.

In that category, I would prefer the MPX Blizzard.
Jun 19, 2012, 09:03 AM
Suspended Account
How can anybody answer this while he never flew the zephyr?? This is ridiculous.
Jun 19, 2012, 10:22 AM
Registered User
Wretcho's Avatar
I was one of the lucky ones to get in on the first batch, had been clicking refresh alot knowing they were due for release

Just finished speaking to HK support, I was wondering why I had not been notified about the postage/tracking number as we all get once our packages leave the warehouse, long story short it looks like my order was stuffed up.
Apparently they will be sending me another from China, then to Hong Kong, through Sydney/customs then a few days later to Perth.
Ill do a review on it next year when i receive it.
Jun 19, 2012, 10:34 AM
Originally Posted by pavcon
How can anybody answer this while he never flew the zephyr?? This is ridiculous.
My question was obviously aimed toward the future a week or 2.
I really wanted to see if any first round buyers had one of these other planes to compare to.
We'll see once the maiden reports come in.
Old Jun 19, 2012, 05:24 PM
A moderator felt this post violated the following rule: Off Topic Advertisement. It is temporarily hidden while hate2crash edits it.
Jun 19, 2012, 08:08 PM
Geez That's A Big Fly
Banjofrog's Avatar
Mine has now made it to Sydney, what I am struggling to understand is why EMS has changed the way express parcels are being delivered, up until the last month or so anything from Hong Kong or China came directly to Perth, now via Sydney which is adding at least an extra 3-4 days than previously, I think Hobby King needs to start asking EMS why? when we are paying for express delivery and it is getting slower, Singapore Post is now faster and cheaper and that is saying something.


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Battery for the Durafly Dynamic-S from Hobbyking Lars N Foamies (Kits) 22 Oct 10, 2013 02:13 AM
New Product HK Zephyr V70 EDF Glider! SHWEEEET! dustydonnay FPV Talk 33 Jun 29, 2012 12:26 PM
Discussion hobbyking durafly 310 question Syner01 Parkflyers 1 Jun 24, 2012 08:54 AM
Discussion Hobbyking Durafly Telemicro Firehawk989 Micro Ready-to-Fly 5 May 13, 2012 09:09 AM
Help! Replacement prop for HobbyKing Durafly P-51 pabo1 Electric Warbirds 3 Mar 28, 2012 02:07 PM