|Wing Area:||1000sq. in.|
|Weight:||9.5-10.5lb, mine came in right at 10lb.|
|Wing Loading:||23.04 oz/sq. ft, 8.74 cubic loading|
|Transmitter:||Futaba 10C 2.4|
|Receiver:||Futaba fast 7 chanel|
|72" Extra 330 SC:||3D Hobby Shop|
|Available From:||3D Hobby Shop|
|Available From:||Aero Model|
|ESC:||Castle Creations hv85 and Pro BEC|
|Available From:||Castle Creations|
|Servos:||Hitec HS 985MG|
I first spoke with Ben Fisher, owner of 3D Hobby Shop, nearly 2 years ago. I had called to see if their carbon wing tubes would work in a biplane I was designing and building. I was impressed that he was willing to talk about a design that was not his. His knowledge of what makes these models do what we want - hover, harrier and just go where they are supposed to - was extremely helpful. When you buy a model from 3D Hobby shop, you are dealing with a company whose owner just loves airplanes and wants to share that love with everyone.
I have the 57 Extra 330SC, and when they first started taking pre-orders for the 72 model, I was at the front of the line. When Ben said he would let me do a review of this new and exciting release, I was honored.
The Extra 330SC Is a single seat low wing aerobatic monoplane. It is the current world champion's full scale aerobatic and Free style airplane. Scott Stoops and 3D Hobby Shop have worked their magic again and released this new and exciting 25% scale aerobatic/3D model in a 72" wing span designed for electric or 30cc size gas motors. The previous models in 57", 103" and 119 wing spans, are known for their precision flight, their lack of rudder coupling and rock-free harrier flight and have been a great success. If this one is anything like its predecessors, it will be an instant must-have.
UPS delivered a big ,double boxed package. There was no damage, and everything was in good condition with each part packaged in plastic bags.
One of the new and big improvements for 72 SC is the use of more carbon fiber. The cross braces and fuselage are reinforced with carbon fiber, making it stronger and stiffer
The landing gear plate is a carbon U channel with carbon rods running through it and the first four formers in the fuselage. STRONG!!
I used a Hacker A50-14l, Castle Creations, 85HV speed control, Castle Pro BEC, 4ea Hitec 985 servos, one 24 servo extension, five 6 servo extensions, 3 spinner and an APC 19x8e prop.
Needed to complete:
I downloaded the manual from 3DHS. I found it to be very easy to follow with pictures for each step of the build. The only thing left to your imagination is installing the electric motor and speed control. I installed the control horns in all the flight control surfaces before doing any further assembly, using Gorilla Glue as recommended by the manual. I went over the motor box and all the joints in the fuselage with thin CA. I also used thin CA on the hatch dowls.
The wings come pre-hinged, and the aileron gap is sealed. All that is left to do is cut out the covering and install the aileron control horn and servo with the included linkage. I installed a washer over the ball link and used Loc-Tite on the bolt.
I installed the rudder as shown in the manual, using Gorilla Glue for the hinges. As stated in the manual, be sure and use Vaseline on the hinge pins.
I used masking tape to mark the location for the cowl screws. I drilled and used the 4-40 bolts and blind nuts to attach the cowl. I used blue Loc-tite to hold the bolts.
The fire wall is pre-marked for center. I lined up the X mount on the center and marked the mounting holes. I used a 1/8 drill to pre drill the holes and then drilled to accept the blind nuts.
I used the Hacker A50-14L electric motor and installed it using the supplied motor mount and the bolt-on prop adaptor.
I used zip ties to mount the speed control and Velcro to mount the BEC. The throttle wire is run behind the BEC and to the side of the battery tray along with the power wires to the receiver. I needed a short servo extension for the throttle wire from the ESC.
I chose to mount the speed control on the side of the motor box. I drilled an extra hole for the zip tie and used Velcro to protect against vibration. I also drilled a hole through the front former to slide the battery wire through.
The supplied motor mounting bolts are long enough for several size motors. For the Hacker A50-14L, I had to put a light ply spacer behind the fire wall to hold the blind nuts. I cut the long motor mounting stand offs to 47mm, which gave me a 3mm gap between the spinner and the cowl.
I would reccomend that the speed control be mounted on the bottom of the motor box for better ventilation.
I used 30 minute Epoxy to seal the battery tray floor and then applied the Velcro to hold the battery in place. I used a Velcro strap through the battery tray and around the batteries to hold them in place. I marked the location of the battery to insure I get it in the same place for each flight.
I used 1/4" nylon spacers from the hardware store on the axle to center the wheels in the wheel pants.
I installed the landing gear per the manual and purchased used 31/4" wheels to fly off grass.
Do not cut the covering off the stab; it actually provides some of the strength to the tailfeathers. I measured to get it centered, made certain that it was parallel to the wing tube when viewed from behind and measured to be sure that it was square to the wing . When I was sure it was right, I checked it again and then used thin CA to hold it. The manual is very clear on installing the stab.
I glued in the elevator joiner to one half of the elevator and used Gorilla Glue to glue the hinges. After one side had dried, I glued in the other half.
I used Lock-Tite on all bolts.
I use Spider wire fishing line to secure all servo extensions.
I used crimping pliers that I purchased at my local fishing store to crimp the pull-pull cables. The cost was about $10.00, and I use it in all my pull-pull applications.
It makes a very solid slip-proof crimp with no risk of cutting the cable or brass tube.
As you can see, the crimp is parallel to the brass barrel and mashes the wires together very tightly.
The cables are crossed between the servo and rudder and just just tight enough to take out the slack. I used the long double servo arm.
I use two 6" extensions plugged into the reciever for the ailerons, two 6" extensions in the wing and one 6" extension from the ESC to the reciever.
I used the long double servo horn for the elevator and cut off the other end.
I was not quite careful enough to be certain that I had the right location for the elevator servo. Luckily, there is extra covering supplied with the kit to fix it when you get ahead of the manual. Look before you cut.
I marked the CG on the wing. The range is from the center of the wing tube to the center of the thumb screw. I had Ben fly mine at the California Huck fest and he liked it set right on the center of the thumb screw. 150mm from the leading edge of the wing at fuslage. This gives a very neutral CG when inverted.
The Extra 330SC can use a wide range of center-of-gravity locations, from 5.25to 6.0 from the leading edge of the wing measured at the root where the wing meets the fuselage. The forward edge of this range will be more nose-heavy for sport and precision flight, the rear edge of this range provides better 3D performance.
Before setting any control throws, I set the end points in my transmitter to 140% (the max that my Futaba transmitter allows).
I set my high rates to 100% and then mechanically set the push rods to the shortest hole in the servo arm that will give me just more than the full travel that I want on each flight surface.
Setting up your transmitter and control linkages this way will give you the best resolution and the most torque that your servos will allow.
I use 3 flight modes, all on one switch: low, medium and high.
Control throw setup
I set my Aileron High rates at 30* using the the throw guage from 3D Hobby shop. Low rates are at 15*
I set the rudder high rate too just where the rudder hits the elevator and low rate to 30*
I have the max throw that the elevator will allow: The elevator push rod hits the stab. I backed off the throw just enough to have no binding on the elevator, which is more elevator than is needed.
I set my low and medium rates exactly per the manual, and increased the elevator throw for the high rates.
Ailerons- Low Rate 15 degrees 30% exponential High Rate 30 degrees 70% exponential
Elevator- Low Rate 15 degrees 30% exponential High Rate Maximum possible throw, at least 45 degrees 75% exponential
Rudder- Low Rate 30 degrees 30% exponential High Rate 45 degrees 75% exponential
Make your first flight with the controls set on low rates. During the trimming phase, 3DHS recommends landing with some throttle and not attempting to dead stick the airplane. This may mean you need to time your flights and keep them a bit shorter than usual. After your first flights, check all control connections and the motor.
Flying the 3D Hobby Shop 72 Extra 330 SC is a pure joy. Tracking on takeoff is straight ahead and very little rudder correction is needed.
On the maiden only a few clicks of trim were required and checking knife edge showed a very slight pull to the gear and no roll coupling. The CG at 150mm from the leading edge of the wing at the root was very neutral inverted. My first landing was with out power and felt a little sensitive on the elevator. I needed to push the nose down just a bit. Now I hold a little power and she just settles right down, smooth as can be.
I mixed in a little rudder/elevator trim for the next flight.
WOW!!! This airplane really does make you look way better than you are.
Rolls and precision flight are very straight, and it excels at IMAC style flying, better with the CG a little forward.
Snaps are very precise and stopping them at any Ό point is just a matter of the correct speed and your thumb timing.
On high rates and with a little speed the roll rate is blindingly fast. Pull the nose up and the roll rate is just right for rolling harriers. There is also ample aileron to control torque rolls in a hover.
Harrier is very stable and rock free. Tight high alpha rudder turns, elevators and parachutes are all very solid with nearly no wing rock.
Knife edge is straight and high alpha knife edge is possible at very low speeds. Knife edge snaps and loops are simple. And knife edge spins are very tight
Water Falls are quite tight and need very little rudder correction.
Inverted flat spins are very good and easy to recover, just release rudder and aileron and it stops spinning.
I have seen no indication of a tip stall, this is a very forgiving airplane. No bad habits and does exactly what you tell it.
The 72 Extra 330sc will give you the chance to become a better pilot whether you are just learning aerobatics or are one of the best free style pilots ever.
|Hover||A||It has a very solid hover with good rudder and elevator authority. With the 19" and larger prop you will need aileron correction to stop the torque roll.|
|Torque Roll||A||Get the Extra 330SC straight up, and with the 19 prop, it will start to torque roll on its own. Give it rudder and elevator to keep it straight up, and it does a very good torque roll. Add some left aileron to speed things up.|
|High Alpha Level Flight||A||This is where the Extra 330SC really shines. Harrier straight ahead has very little to no wing rock and needs a balance of elevator and throttle. Tight rudder turns need a little aileron and power, but it still has very little wing rock. Elevators are solid, and throttle controls the rate of descent. It's nearly straight down and a very easy transition to harrier or hover. Parachutes are equally solid: Dive straight down with full elevator. Add some power to transition to harrier. It has no tendency to tip stall, and you can do them scary low.|
|High Alpha Inverted||A||Very good with no wing rock. I still need more inverted practice for rudder corrections but the Extra 330sc is really helping me with its gentle stable flight.|
|Flips (high alpha half loops)||A||Great from level inverted flight or a hover. Just go full down elevator, and blast the throttle. No tendency to tip stall or drop a wing. Come off the power on the down side. Repeat as necessary.|
|High Alpha Rolling||A||Again, very nice! Minimal corrections.|
|High Alpha Knife Edge||a||WOW! She excelled here. Very little rudder mix needed.|
|Stall Turns||B||Again, very nice. At the neutral CG, it need a little power to look right. I moved the C.G. forward to one more suited for IMAC, and it is even easier. No corrections needed .|
|Knife-edge-to-knife-edge turns||A||Plenty of rudder and solid at any angle of attack.|
|Wall||A||dependent. Full elevator and she rotates to a perfect vertical. Do it downwind, and she just keeps sliding down the runway pointing straight up. No tip stall.|
|Flat-Spin||A||Flat spins and blenders look great. I use less than full elevator and power to hold the nose level. They are very, tight and flat with a nice slow descent. Exit is very solid inverted; neutral rudder and aileron low power, and then just fly out by just adding back a little power and coming off the elevator.|
|Waterfall/loopet||A||It can flip over right on the wing or by coming off the power on the back side. It parachutes down until you give it power to pull the nose back up.|
|Knife edge spin||A||Can be entered from knife edge or an outside snap at the top of a long climb. Full down, full left rudder and full power, find the sweet spot for the aileron. For mine it is just a little left aileron. It spins so fast the prop capitation is as loud as a DA 50. Exit is idle, neutral rudder hold the down elevator.|
No! This is a high performance aerobatic model. On low rates and with a slightly forward C.G. it would be a very good first aerobatic model. It is light, stable and has no bad habits.
For me there are two kinds of airplanes: those that make you work, correct, fight, and you just never quite find the confidence to really show it off, and those that really beg you to throw them around, have that feel and balance that you have always dreamed about, ask you to get it low and flirt with the dirt a bit, just doing what you tell it to.
The 3D Hobby Shop 72 Extra 330sc fits into the last category. You wont be fighting wing rock when you are on the deck in a high alpha harrier, you wont be fighting the ailerons and rudder when you are trying to learn a knife edge loop. You will feel safe when you do a couple extra turns in that flat spin, and dragging the tail and hovering on the deck are just a few more tricks the Extra will be begging for.
If you are looking for a great easy to fly sport aerobat, an IMAC practice plane or something to get really wild with in you next 3D free style routine then you will love this airplane just as much as I do. I really like this airplane. They have really dialed in the aerodynamics; it is light strong and well engineered.
|Jan 16, 2011, 12:05 PM|
I flew it yesterday, first time with good weather in a long time. It just keeps getting better and better.
Let a friend fly it that is one of the better 3D fliers in our aeria and he was amazed at how solid it was how easy to hover and how big it feels in the air. He just set the tail on the deck and started to torque roll, kept saying WOW! WOW!.
|Jan 19, 2011, 09:08 AM|
Nice review Dennis. My Red, White and Blue 72" is just being finished now. I am looking forward to tearing it up with this...and my AJ Slicks. LOL
|Jan 19, 2011, 12:53 PM|
I especially like the video of Andrew Jesky and Joe Smith, Andrew starts out with a precision one roll loop followed by some precision snaps to knife edge, followed by Joe's tight rolling harrior loop. Then both just thrashig the heck out of it.
Richard, You flew mine at the huck fest so you know you are goint to like it when you are done.
You are welcome to come up and fly any time
PS: I have a new kit for the Unobtainium biplane and it is comming along.
|Jan 19, 2011, 10:15 PM|
Very nice review!!!! Great Job!
It is very cool that you got a good picture of carbon U-channel. I think that whole concept is really impressive and some real thought has been put into it.
|Jan 20, 2011, 07:35 AM|
|Jan 20, 2011, 09:24 AM|
|Jan 21, 2011, 01:33 AM|
I'll also note that mine is awesome on 6s 5000. I will admit that I am curious about what 8s would be like, tho.
|Jan 21, 2011, 06:35 AM|
I use 8s 4000 and 5000. It has alot of power The 5Ks help in the wind. Other than that the weight isnt really all that noticable.
|Category||Thread||Thread Starter||Forum||Replies||Last Post|
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