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Sep 30, 2014, 05:52 AM
Taranis Tyro...
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New Product

Durafly EFX Racers - Owners Thread

Welcome to the owners thread for the Durafly EFX Racer. The first few posts will be updated as further information becomes available at launch; in the meantime here are the key pieces of information garnered during the EFX Racers design discussion thread...

Release videos:

Durafly EFX Racers PnF & Kit - HobbyKing Product Video (3 min 11 sec)

Durafly EFX Racers - HobbyKing Daily (7 min 5 sec)

Durafly EFX Racers - Product Profile Hobbykinglive (14 min 44 sec)

Purchase links and manual:
Pre-release videos:

HobbyKing Daily - Joe Nall Exclusive Durafly EFX Racer (1 min 0 sec)

~FAST~ HobbyKing Durafly EFX Racer (2 min 50 sec)

JN HobbyKing Tent (5 min 25 sec)

The model was released on the 30th September 2014 (despite the best efforts of HK's IT infrastructure to push it into October... ). The EFX has a 43" wingspan, digital servos all round (MG on the wings), is 3S or 4S powered and 100mph+ on the stock setup - they're gonna be popular!

More pre-release titbits from Stuart...
Originally Posted by stuart warne
It's 3 and 4s capable and 102mph is the fastest I've got out of the model in development thus far (4S), but that's the stock set-up.
Originally Posted by stuart warne
There will be limited kits available.
Originally Posted by stuart warne
good easy battery access on top via hatch and she'll fly on a 2200 3S or 1800 4S. We get a good 5 mins on the 4S using throttle most of the time and 7+ on 3s.
Originally Posted by stuart warne
Under arm is THE way to launch, these NY flyers, you just can't get the staff

Re: mods etc, as you wish, but there is already reinforcement for the aft fuzz and the wing is plenty strong enough. 4S is for 1800, 2200mah for 3S. You could squeeze a bigger 4S in if you wish, but the idea is with the 1800mah 4S you have enough flying time to enjoy it, but not too much those your nerves are fried by the end of the flight You will welcome a break after flying fast

That said, I welcome and encourage all to mod/make there own etc, and the airframe will take it so please mod as you will, it's all part of the fun if you wish, but you should give 'standard' config a go first
Originally Posted by stuart warne
(The battery bay is...) Approx L120*W38*H35mm
Originally Posted by mlee8249
These are the readings I took from the plane. Tachometer is a Fromeco optical...very accurate!

POWER SYSTEM: 28-36 2300kv brushless outrunner
FULL THROTTLE POWER: 41.2 amps, 595 watts (4S, 5x5 prop)
TOP RPM: 28,600RPM
DURATION: 4 minutes @ 100% throttle, 5-7 minutes @ 60% throttle (4S battery)

I was very pleased with the RPM. I will tell you this....for sure, balance that prop or there will be hell to pay!

Mike Lee
Courtesy of Fly RC Magazine
Pre-release review:
Originally Posted by Bajora
I just received a pair of the EFX racers as a part of a feature article on SPEED that we are doing for FlyRC. The out of the box quality of this DuraFly model is the best I have seen yet! Great instruction manual, very nice vinyl graphics that look like they will not easily get displaced, wingtip skids on the bottom and centerline protection for those who fly off hard surfaces, ball link connections for pushrod to control surface connections, etc. I assembled one last night in less than an hour, not counting the time spent shooting a bunch of studio photos. These models look really nice!
Originally Posted by Bajora
Flew both 3S & 4S models Sunday AM. Wow, I am loving these racers. I think Durafly has a really big hit on their hands with these little speedsters. Both maiden hand launches were non-events. The whoosh of the airframe on a high speed pass is especially cool. The guys at the field who saw me fly them went nuts over them!

The only difference between the two models is the color scheme (red or yellow). Both include a 5x5 prop for 4s (recommended size is 1800mAh) and a 6x5 prop for 3s (recommended size is 2200mAh).

I used the new A-Spec 4S 1800 when flying the red one on 4S. Red IS always faster! She goes like stink!
Addition - Much of the original EFX thread was taken over by discussions over the lineage of the EFX Racer design and it's similarities and differences with the Ralph Roberts designed Zephyr slope soarer. No copyright infringement has been found to occur, but many people in the thread indicated they would like to donate to Ralph when they buy their EFX, so instructions on how to do this have been posted here. As this matter has been discussed at length already, can I please ask that we do not talk about it here but instead focus on enjoying the EFX; if you feel strongly about this issue, the option to donate is available to you. Many thanks!
Last edited by MattyB; Oct 01, 2014 at 03:56 PM.
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Sep 30, 2014, 05:52 AM
Taranis Tyro...
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Product info

EFX Racer PNF instruction manual on Dropbox

The Durafly EFX Racer has been designed from the ground up to offer the speed (100mph+) and strength normally reserved only for high end full composite models, but with the handling and satisfaction only a Durafly model can offer.

This 1100mm (43") span model boasts a huge list of high performance features that set the EFX apart from the competition. The 2300kv 28mm brushless outrunner (designed specially for the EFX) uses ultra high speed Japanese bearings for only the best performance. The pre-installed Durafly 50amp ESC has been optimized to deliver smoothly the power you need, when you want it and all control surfaces use high speed, high torque digital 9g servo's (metal geared on the ailerons) together with ball link connectors to deliver true precision and control through-out the speed range.

The EFX Racer's high performance doesn't end with the electronics. The airframe has been engineered to be both rigid and lightweight, utilizing both glass and carbon fiber reinforcements throughout the model in combination with Super Compressed EPO foam and a highly polished surface finish to deliver the ultimate in performance in the air and the sleekest of looks on the ground. Following the supplied comprehensive manual, the EFX clips and screws together in minutes. Connect the control surfaces to the servos and install your own choice of receiver & lipoly pack and you are ready to fly!

Versatility is another of the design features of the EFX Racer. Right out of the box you're provided with two different power options, 6x5 for 3cell and 5x5 for 4cell. For good all round sports performance a 2200mah 3S lipo on the 6x5 will give good speed and is recommended for pilots less experienced with fast models. However, for true high speeds and power when you open the throttle, a 1800mah 4S on the 5x5 is the winners choice and will get you going over 100mph. For the ultimate speed/performance on 4cell, a 5.5x4.5 is recommended for 100mph+.

Complimenting the amazing speeds of the EFX is it stunning agility in the air. A simple under arm hand launch at 3/4 throttle from standing gets the EFX in the air and you'll have unlimited vertical as soon as you open up to full (4S). A full house of controls (Aileron, Elevator, Rudder) gives the EFX remarkable aerobatics performance. Loops can be as BIG as you want them, rolls are very precise either fast or slow and the EFX will knife edge all day long! Thanks to the exceptionally strong airframe, high powered, high G maneuvers will not present a problem either. The EFX Racer never fail you, but always leave you wanting more! It's not all about going fast and turning hard, you'll find the EFX handles exceptionally at slows speeds with both elegance and confidence inspiring grace. This is especially true in landing where you'll find no hint of a stall and good control all the way down to the ground.

Whatever set-up you choose and however you prefer to fly, your EFX Racer will perform and deliver time and time again and always keeping you coming back for more.


• 100mph+ performance right out of the box (on 4S set-up).
• Specially designed NTM motor with high speed Japanese bearings.
• Powerful and fast 9g digital servos.
• Supplied with 6x5 propeller for 3S and 5x5 propeller for 4S set-ups.
• Super Compressed EPO foam construction.
• Glass and carbon fiber reinforcement through out the airframe.
• No glue assembly. Just clicks and screws together in minutes.
• Ball link control system.
• Full compliment of spare parts available.

Wingspan: 1100mm (43")
Length: 760mm (30.2")
Flying weight: 720g (25.3oz)
Motor: 28-36 2300kv NTM Brushless Outrunner (with high speed Japanese bearings)
Prop: 6x5 (3S) and 5x5 (4S) supplied. 5.5x4.5 suggested for 100mph+ performance.
Battery: 1800mah 14.8V 4S (30C min) or 2200mah 11.1V 3S (30C min)
Servos: 4 x 9g digital servos (metal geared on ailerons)
ESC: Durafly EFX 50amp with XT60 plug
Receiver: 4-6 channel full range recommended.

4-6 ch receiver and transmitter
1800mah 14.8V 4S (30C min) on 5" prop - 2200mah 11.1V 3S (30C min) on 6" prop
Last edited by MattyB; Oct 01, 2014 at 03:55 PM.
Sep 30, 2014, 05:52 AM
Taranis Tyro...
MattyB's Avatar
Thread OP

Reviews, resources, ips and tricks

IMPORTANT - Check your motor mounting, some have been found to have issues...

Turnigy Efx 100mph+ Racer - must check (1 min 25 sec)

Non-HK reviews & flight videos:

(2 min 58 sec)

RCGroups Durafly EFX Racers (3 min 55 sec)

UPDATE - Added v2 EFX model setup, instructions, sounds files and model image for FrSky Taranis - features below:

General features (all flight modes):

• Throttle kill on switch SF with pre-flight check reminder.
• Flight countdown (reset by throttle kill on switch SF) and total model time timers.
o 4S memory set at 3.45 flight time; 3S at 6.00.
• Flight time remaining called out by short press of switch SH.
• RSSI called out by long press of switch SH.
• Speaker volume adjustable via S2.
• Model name announcement on start-up/selection.
• EFX racer BMP file included.

Flight mode specific features:

There are 6 flight modes – Takeoff, Acro-low, Acro-med, Acro-high, Speed and Landing.

Takeoff (selected by SE↑)
• Throttle limited to 90% to prevent excessive torque on takeoff; custom curve to remove non-linear throttle response (curve 1).
• No selectable rates (defaults to medium rate aileron, low rate elevator, low rate rudder).
• Takeoff mixes - For 10 seconds after motor live (SF↓) and 5 seconds after throttle stick advanced past half throttle (0) point:
o 10% up trim to help with solo one handed launches (particularly for RH mode 1 flyers).
o 30% coupled aileron→rudder to help with corrections to counteract torque.

Aerobatics (SE-; Acro-low selected by SA↑, Acro-med SA-, and Acro-high SA↓)
• Throttle limited to 90% for improved battery life and flight duration (custom curve 1).
• Triple rates (aileron, elevator and rudder) on switch SA (actually flight mode changes).
• Knife edge compensation mix (Rud→Ele), set to zero weight by default (configured by curve 3).
• Snapflap (elevator to flap) mixing available (default 30% weight; configured by curve 2).
o Snapflap volume adjustment on pot S1.
o Snapflap suppression on switch SG.
Speed (selected by SE↓)
• 100% throttle available; custom curve for increased resolution at high throttle settings (curve 4).
• “Nagging Nora” max power warning when at uninterrupted full throttle for 25 seconds or longer.
• No selectable rates (defaults to low rate aileron, low rate elevator, 0% rudder to prevent tail wagging).
• Snapflap (elevator to flap) mixing available (default 30% weight; configured by curve 2).
o Snapflap volume adjustment on pot S1.
o Snapflap suppression on switch SG.
Landing (selected by RS↓; overrides all other flight modes)
• Throttle limited to 90% to prevent excessive torque effect on a go around; custom curve 5 moves throttle to top half of stick movement (0 to +100%).
• Flaps and airbrakes (reflexed ailerons) activated by throttle stick from 0 to -100% (custom curve 6):
o No flaps or brakes activated whilst motor on (throttle stick 0 to +100%).
o Flaps deployed between throttle stick settings of 0 and -20%
o Brakes deployed (ailerons go up) from throttle stick settings of -20 to -100%; elevator compensation available in mixer, zero weighted by default (direction still to be determined).
o Negative aileron differential programmed with brakes (two levels, activated at -30 and -90 throttle stick travel respectively using GVAR1).
o For large brake settings (throttle stick <-90), 30% coupled aileron→rudder mix activated.
• No selectable rates (defaults to medium rate aileron, high rate elevator, med rate rudder).
Last edited by MattyB; Oct 31, 2014 at 10:58 AM.
Sep 30, 2014, 05:59 AM
Houston. .we have a problem.
FOX ONE!'s Avatar

Uk warehouse buddy discount code!

Yeah, Just got the order in at 2:00pm UK time!

Was planning on going down to the HK Warehouse to be the first customer to take delivery, but as it's only just been made "live" on the site, and it's a 3 hour drive away from me, I'll have to settle for waiting for the post to arrive!

I have quite a few 2200mah 4S packs knocking around, so hopefully will find a fit, but thought I'd better play it safe & order the "recommended" pack, too!

Here's a UK Warehouse Buddy Price Code for £6 off guys!! (you have to be logged in to HK to see the discount, so log in to your HK account FIRST, then open another tab or window & click on the link here):
Last edited by FOX ONE!; Sep 30, 2014 at 04:59 PM.
Sep 30, 2014, 06:03 AM
Registered User
Last edited by berazafi; Oct 08, 2014 at 04:46 AM.
Sep 30, 2014, 07:09 AM
Registered User
ChickenDrumstick's Avatar
Looking forward to these. Although I think I'll wait for the first rush and some flight reviews before ordering. But certainly a plane on my 'to buy list'. But only in yellow
Sep 30, 2014, 07:32 AM
Retired US Navy
Evan D's Avatar
Today, today! Ordered from east coast US warehouse.
Last edited by Evan D; Sep 30, 2014 at 08:22 AM.
Sep 30, 2014, 07:53 AM
Bajora's Avatar
AND THEY JUST WENT LIVE AT 5:55AM Pacific time !

Some video of the 4S EFX Racer shot this past Sunday. The pilots at the field that I fly at have been quite impressed by these models. In the video, I handed the sticks to one of them and let him have at it!

(2 min 58 sec)

And some photos I have shot over the last few weeks :

Last edited by Bajora; Sep 30, 2014 at 07:32 PM. Reason: Added photos
Sep 30, 2014, 08:01 AM
Head of aircraft dev Hobbyking
Stuart Warne's Avatar
I'll contribute to the thread to officially kick things off

Durafly EFX Racers PnF & Kit - HobbyKing Product Video (3 min 11 sec)

I look forward to seeing the reaction to the model and thank you all so much to for the interest, support, enthusiasm and most of all patients for this model.


Sep 30, 2014, 08:05 AM
Registered User
TheDavecal's Avatar
Just ordered it.

Sep 30, 2014, 08:27 AM
Registered User
rembrand320's Avatar
Just ordered the Yellow Slow Flyer
Sep 30, 2014, 08:30 AM
Registered User
Stuart thanks again for your hard work on this model. I have been reading about this plane for a while and decided to get my first durafly plane with the red efx! Can't wait to get it.
Sep 30, 2014, 08:35 AM
Registered User
MartinT's Avatar
Buddy code Europe yellow one:

Buddycode Europe Red one:

Do it guys! ;-)

Thanks For the hard work Stuart!
Sep 30, 2014, 08:37 AM

Buddy code US East Red save $10!!
Sep 30, 2014, 08:38 AM
.....and that's why I crashed
Lusby's Avatar
I'm in, yellow EFX on the way . You could see the stock indicator go down on each visit to the page, I better not get a 'we went to pack your order but were out of stock' email. Cant wait.... as usual it was cheaperfor both plane and postage from the international WH than the local Aussie WH so I have a longer wait than i'd like

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