Hobby-Lobby F/A-18 "Red Viper"

Tuesday, June 24, 2008

By Jamie "GFBurke"
Specifications:

Manufacturer:StarMax
Name: F/A-18 "Red Viper"
Distributor: Hobby-Lobby, Intl
Type: Electric foam Ducted Fan Jet
For: Intermediate to advanced pilots
Flying weight: (review model): 19-3/4 oz. (560g)
Size: 28" (686mm) wingspan, 37" (980mm) long
Prop: 5 blade ducted EDF
Radio: Airtronics RD6000 Super transmitter with Hitec 6s Receiver, 4x 9g Servos.
Power system: MOTOR 14L inrunner EDF, 25A ESC, 3s 1300mAh 18C lipo.
CG: 580mm from nose tip


Introduction:
The new F/A-18 "Red Viper" from Hobby-Lobby is decorated in the scheme of the The "Diamondbacks" of VFA-102, complete with decals!

I have never flown an EDF jet before, but I love the idea of not seeing a prop sticking out and not having to worry about being hit by it! And of course, the sound is very appealing.

Unpacking:
Upon opening the box, everything seemed to be in order. All the parts were wrapped individually in plastic, then placed into a nice egg carton container.

All four servos are already glued in place with the control horns tightened on. The motor and ESC are at home and ready as well. The airframe is molded of a hard foam much like that of the Stryker.



The two servos that stick out of the fuselage are "Y'ed" together. These two servos control the elevator and move together on the same channel. The nose carries the steerable front wheel, so there is nothing to do to set up the ground control. I cannot get a close shot of the motor or ESC, so I'm not so sure what name brand they really are. Deans connectors where already soldered on the ESC and lipo (yea for me!).




I noticed the nose cone is made of a very soft material, as shown in these pictures. I'm sure this is for weight reduction, however I'm not so sure it's going to withstand my awesome landings.




Building:
The instructions say to glue the fuse halves together, however this was already done for me. Not only was the main fuse together, the 4th (aileron) servo is hidden in the fuse. This one servo connects to the rod going through the fuse, then into the main wing rod setup.

Step one was to put the landing gear in place. The design of the holder would allow the gear to be placed on backwards, since the hole for the aluminum are in front and in back. I studied the pictures of completed models, and set them up correctly.



The next step says to "put the control horns in". Well, that's about all the help you get! As you can see, the job requires a bit more thought on just how to make this all work. In the picture below, you can see that you only get 8 screws so that means 2 screws per horn. For extra peace of mind, I used the goop that was included on top of the 2 screws to really hold in the horns.



Designing this mechanical movement with just "install the control horns" takes some thinking. Not a big deal once you see it, but no real pictures were included to show you how. So this is what it looks like when it's good to go. All in all, it's a very cool design and unlike any setup I've seen before. The short rods are used for the ailerons, and the longer rods are used for the elevator. It works very smoothly.

I found it was easier to put the goop on the wing, then insert the aluminum stick that comes out of the fuse into the screw holder. Basically, thread that stick in the hole while gluing on the main wing. Otherwise, you will have to remove the screw that holds that strange "two-armed horn" then thread it through.

Be sure to get all rods and threads the same length on each side. Of course, turn on the radio and zero out the servo then align your control surfaces, then tighten up the screw that holds the threaded aluminum rod.





The next step is to put on the wings. This part was simple because everything fits nicely together and is obvious where each part goes. Again, I just used the standard goop that came with the kit (this is the same as the GWS goop).



Now we need to put the nose section onto the main fuse and body. Make sure all your and servos are working! Plug everything in and do a quick test to avoid pain later.

The fuse and nose fit together perfectly. You will need to decide on your electronic equipment placement before you glue this in. There are two opening doors, but the manual doesn't state what is for what item. However, to get the CG properly set you really only have one option: Put the lipo up front. In order to place the included lipo in the front hatch, you must cut a little bit of foam to get the deans and wires through. The front wheel servo will also be going into this area to reach the back hatch and RX.





I pulled my wires where I wanted them, then put glue on the nose piece and slowly placed the nose while pulling wires at the same time being sure nothing was going to get pinched.


Yes the plane now has proper center of gravity (per instructions) with the 3s 1300 in front and the RX in the back hatch.


Finishing up:
I didn't install the drop tanks for now, but I may later since it will give it a better scale look. I wish it came with a couple of Sidewinders for the wing tips! That would be cooler than drop tanks. Incidentally, the manual states these are "missiles" but no, just drop tanks. I can guess where they go but nothing is stated as to where to install them anyways.

Technical specs:
24A @ 259W WOT
Plane starts to roll @ 1.5A
All up weight with lipo (rtf) = 584g

Flying:
The jet taxis on the ground with ease. Lift-offs are smooth, and roll rates are solid and quick. The jet feels good in the air and moves quickly on low passes. It loses speed really quickly on tight turns, however in an easy turn you retain most speed. This is probably a feature of most EDFs, but I have nothing to compare to since this is the first one I've flown. The way it is out of the box, it is slightly nose heavy. This can be fixed by moving the lipo back slightly.

As with many military models, orientation is easily lost if you fly out too far, and that is a scary feeling! If you know the craft well, then you should be ok taking it out further.
Landing are nice and smooth. You can take her in slower than you think and almost "harrier" it in. I was quite amazed as I attempted to stall the jet facing into the wind. It almost came straight down on the wheels! It is very easy to land, even for somebody like me.



A beginner aircraft?
The plane isn't designed for a beginner flier. However, since most everything is already done for you, a beginner could probably put it together if somebody with some experience was there as a mentor. I think with better instructions a beginner could do it just fine, but as it is the instructions consist of about 5 steps. The pictures are tiny and one whole step is dedicated to setting up all horns and controls. It states "Connect the control rod with clevis". That's really not adequate for someone who hasn't put together a few models already.


As a side note: What year is this? I understand that full graphic images can be costly to print, but a URL in the manual to a wiki or some other collaborative build guide would be very helpful for everybody. Most RC models suffer from inadequate instructions, but a wiki is free. Ok, off the soapbox and back to the review.

Negatives:
- The manual and paper-thin nose cone.
- The CG point is not correct in the manual. You need it about 5mm back from the specified point.
- The clevises need to be secured more than just the "snap in place" method provided.


Conclusion:
This model is an amazing value. For under $200, all you need to add is your own transmitter and receiver. If you heed the cautions on center of gravity and securing the clevises, you should be just fine. We chose to put some mechanical "up" in the elevator and used a bit lighter lipo in the front to get proper CG. I think many people are making both compartments together as one, then mounting the lipo in about the middle of the chambers. Keep her in close if you have orientation issues or older eyes. The landings are super easy!


Things I would have done differently now that I've built one:
1: I may leave off the lading gear entirely since I fly in nice grass. Remove the 4th servo and LG to save some weight.
2: Could be possible to setup that 4th servo to do a rudder or a thrust vectored mod.
3: Find some Missiles!


Video

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Hobby-Lobby F5B Tiger Review

Sunday, June 15, 2008

by Chris "JustPlaneChris" Boultinghouse

Specifications:

Distributor: Hobby-Lobby, International
Type: Sport or F5B Competition
Flying weight: 38 oz. / 1077 g
Length: 36.5 in. / 927 mm
Wing span: 67 in. / 1701 mm
Wing area: 330 sq in / .212 sq m
Wing loading: 16.5 oz/ sq ft / 5.03 kg/ sq m
Radio: JR 9303 transmitter with DSM2 module, Spektrum AR6200 receiver, 2 Hitec 125MG thin wing servos on ailerons, and a Hitec HS65HB for the elevator
Power system: AXI 2217/9D + PG3 outrunner motor w/Gearbox, Jeti Spin 44 ESC, and PolyQuest 3300 3S Lipo. Prop is Aero-Naut 14x12 carbon folder.
Power output (static): 46 amps / 527 watts, 5200 rpm
MSRP (airframe only): $339.90
Price as tested (not including transmitter): $970.20

Introduction

The F5B Tiger, distributed by Hobby-Lobby, International, is a fully-molded electric-launched sailplane. This type of model is often referred to as a "hotliner", and is similar to the models used in F5B competition. For those not familiar with F5B competition, the models are required to fly both distance (speed) and duration tasks, with the caveat that the motor cannot be run while on the course. This means the models must possess incredible rates of climb, since they must streak back to altitude as fast as possible before re-entering the course, as well as the ability to go fast and glide for long distances. Of course since they need to make "pylon racer" turns at both ends of the distance course, the models must also be extremely strong to withstand the g-loading. The Tiger fits the description! Soon after Hobby-Lobby contacted me to do this review, a large box arrived at my door. Having built and flown many models over the years, I have pretty high standards when it comes to fit and finish so I wasn't sure what to expect when I opened the box. I am happy to say I was very impressed with the workmanship and quality. All the details were there - from the wing bolt sockets to the "wipers" on the ailerons and elevator. The airframe is of absolutely stunning quality, with no imperfections in fit and finish to be found no matter how close you look. Let's get on with the build!

Construction

There is really no "building" to be done with the Tiger, since the airframe is completely molded and arrives fully assembled. The wing and tail are bolt-on affairs, so the only tasks left up to you are the installation of the servos and the motor. Hobby-Lobby provided a fiberglass firewall with my Tiger, but unfortunately the bolt pattern of the AXI motor did not match any of the holes. Upon further measuring, even had I slotted the mount for the bolts, there would have been very little material left around the bolt holes. Since the mount is also too large to fit inside the nose without sanding, I simply made a mount from 1/8" aircraft plywood. The mount was then bolted to the motor and slid in from the wing opening. Once I was satisfied with the fit and position, I mixed a batch of 30 minute epoxy and milled glass fiber to a thick consistency and epoxied the firewall in place. A neat trick is to use the prop hub/spinner assembly to assure the mount is parallel with the front of the fuselage. Simply slide it onto the gearbox output shaft until it touches the fuselage, while pushing the motor forward from behind (use a stick to reach it). Tighten the retaining bolt and let everything cure.

Servo installation may be a bit of a surprise to some folks, since they are epoxied into the airframe! The first step is to remove the mounting lugs, since not only can they not be used, but they also simply won't fit if you leave them on. There are no pushrods supplied with the Tiger, so I picked up some 12" standard pushrods and Sullivan clevises from the hobby shop. The aileron pushrods are quite short, with Z-bends on the servo end and a clevis for the aileron horn. Speaking of the horns, these are nice brass units that thread into sockets that are molded right into the ailerons! All I had to do was drill out the hole slightly so the clevis pin would fit, then they were threaded into the ailerons.

Fishing the servo wires down through the wing is made easy with pre-installed pull-strings! Just plug in a 12" extension cable, tape the string to the end, and pull it through to the opening in the center of the wing. Here's a trick: Use a length of waxed dental floss to tie the connector together on the extension so it can never come unplugged.

The servo horns must be trimmed quite short in order to fit everything under the supplied servo covers, but that doesn't present any problems since you don't need much control throw anyway. One item to note: You will need to notch the lower wing skin so the aileron horn can move forward, otherwise you won't be able to get any downward aileron travel. A rotary tool made short work of that task.

Once I was satisfied with the linkage geometry and operation of the servos, I cleaned the servo case with denatured alcohol, then carefully wrapped the servos with good quality clear packing tape. The seam is on the upper side of the servo, and the bottom side was carefully scuffed with a scouring pad to promote adhesion. This is done so that if the servo ever needs to be removed, one can slit the tape and (eventually) peel the servo out. I then mixed up a batch of 30 minute epoxy, thickened it with colloidial silica, and epoxied the servos in place. Be sure to clamp the ailerons level when doing this. Care taken here will assure a first flight that brings no surprises with out-of-trim ailerons. When the epoxy is cured, make sure your ailerons still wiggle the right way, then tape the servo covers in place with bits of clear tape. The wing is now complete!

Installing the elevator servo proved to be trickier than the aileron servos. There is no horn provided for the elevator, so I made one from a bit of carbon fiber plate I had in my scrap bin. You could also use a scrap of printed circuit board, or even 1/16" aircraft plywood (though I'd soak the pushrod hole with thin CA for durability). The pushrod simply has a 90 degree bend on the elevator end, and a Z-bend for the servo. Obviously there is no way to adjust it, nor can you remove the servo arm once it's installed, so be sure you get it right the first time! The elevator servo arm must be trimmed even shorter than the ailerons, so you must be very careful with the Z-bend geometry to allow proper elevator travel without binding. Again, just take your time and make sure it's right before you epoxy it all in place. As with the aileron servos, the elevator servo was wrapped in tape before being epoxied into the fin. A nice cover plate hides it when installed.

The rest of the building is simply installing the receiver, ESC and battery pack. Initially I was concerned that the motor wires might try to rub against the outrunner motor, but their stiffness combined with the location of the ESC keeps them tucked tightly against the inside of the fuselage. Just be sure to check yours, and if they try to rub use a bit of double-stick foam tape to hold them to the inside of the fuselage. The battery pack needs to be just about as far forward is it'll go (without touching the motor) to get the CG in the correct position. Hobby-Lobby recommends the CG be set at 2.5" aft of the leading edge at the root, and I found that to be a nice setting based on how it flies.

Flying

The weather here in Central Texas has been abnormally windy this year, putting a damper on flying anything other than larger helis and planes. Add to that the record-setting heat, and we decided to go for an early morning first flight for the Tiger. We arrived at the Austin Silent Flyers field at 7:30 am on a Saturday morning and set up the Tiger. After the obligatory pictures, range check, and camera-person briefing it was time to put this beauty into the sky. My friend and fellow aviation addict Rob had the honors of tossing it for me while my lovely bride Liz filmed. After one final control check I added about half throttle, Rob tossed it, and away it went. After it left his hand I rolled on full power and pulled it vertical. I think I can summarize the climb in one word: Yeeeeeehaaaaaa! After climbing for only 5 or 6 seconds, I shut down the motor and pushed over at the top. The aileron trim was perfect, but I did need to add a few beeps of down elevator for a hands-off glide. The first turn revealed a bit of adverse yaw, which was easily corrected before the second flight with a bit more aileron differential. Other than that, the flight characteristics are simply amazing. It is smooth, it is fast, and it has no bad habits at low speed. Even though it was early morning, I was able to find and work a couple of small bubbles of lift. I can already see that it is going to be one of those "fly it till your neck hurts" planes, with such good thermalling ability from only a 5 second climb! Of course, the most fun part of a plane like this is to convert altitude into airspeed, and show off with fast passes, large loops, and other smooth aerobatics. The Tiger excels at this, and emits a very pleasing whistle (no doubt from the cooling hole in the spinner) as it screams by in a fast pass.

Conclusion

I can honestly say this is one of the more enjoyable planes I've flown in my 28+ years of RC flying. While certainly not cheap, the Tiger is a stunningly beautiful model that flies as well as it looks. The power system that Hobby-Lobby recommends pulls it vertically without effort, and is a fine choice. However, if you are on a budget, you could certainly use a lower-priced low-kv outrunner direct drive and still have a lot of fun. A search of the electric sailplane section of some of the online forums will reveal several power system options to consider.

While we did get video of the first flight and some flybys, my camera people had a very tough job. This is a very fast model, and it gets small very quickly. Combine that with the white wings and cloudy sky, and they had a nearly impossible job trying to follow it in the viewscreen. So please do keep that in mind while watching the videos, and don't think badly of their camera skills.

If you are an intermediate to advanced pilot looking for something different, or are a dedicated sailplane guy who wants to try a self-launcher, please do give the F5B Tiger from Hobby-Lobby a look. I don't think you'll be disappointed.

Note: If you would like to see all of the 100+ photos that I took during the build process, check out my Flickr album.

Videos