There is one major difference, though. TufFlight already specialized in developing gas planes that could withstand rough treatment during combat flying. And unlike some companies, TufFlight seems to look for ways to improve their existing offerings. This is version number 3 of this particular aircraft. That says a lot to me about the company. So what is 4D? It is 3D + Durability. If anyone can test that claim, it is me for sure.
Joe from TufFlight notified me when the plane would ship and also offered this advice:
"Please bear with the assembly. It's different, but it shouldn't take much more
than a day or two to finish. Let us know how you make out." Oh boy! I wasn't sure what
to expect after that.
|Wingspan:||32"||Motor:||Himax 2808-1160 outrunner|
|Length:||31"||Battery:||Thunder Power 3s730 LiPo|
|Wing Area:||286 sq in|
TufFlight offers 3 versions of the kit: The basic kit, a complete kit based on a geared GWS motor, and a complete deluxe brushless kit. The complete kits contain everything except the radio and batteries. They even include a spare prop and spare motor mounts. I opted for the brushless version as I have become a believer in brushless motors. But even with the less expensive versions, I have to say that they use quality parts throughout. And they also show how to modify the less expensive GWS motors to use a prop saver type of arrangement. A nice touch for those on a budget. They even included special sized drill bits.
The first 13 steps were the most tedious and time-consuming, at least for me. You had to trace the parts templates onto plastic sheets using a hobby knife, then drill and cut out each rib and control horn from these sheets. I was a nervous wreck trying to trace these with a hobby knife, then "snap" them from the plastic. I was so afraid of breaking the parts. It took some effort to free the parts, but I found the plastic to be extremely tough, and everything worked as the instructions said it would. I can see how unlikely it would be for any of these plastic parts to break. They are very light and flexible.
I skipped on to some of the other steps at this point while I decided how I was going to paint the plane. I really liked the looks of TufFlight's planes with the flames. I eventually decided to try my luck at using my never-used airbrush. Completing some of the other steps enabled me to paint both the tail and wings at the same time. The manual contained flame templates for the tail surfaces. I drew the template for the main wing. I have to say that it didn't turn out too bad.
There is little chance of getting the alignment wrong as the tail surfaces mount into the pre-drilled holes in the skeleton. Control rods are bent to shape using full-size patterns, then attached using the supplied Dubro EZ-connectors and quick-links.
Once I worked my way through the wing assembly I could see just how unique it was in terms of design, especially for strength without weight. Rather than having a wooden, plastic, or even carbon fiber support across the wing joint, it uses several pieces of kevlar thread that have been saturated with CA. Once this hardens, it is quite stiff. I am anxious to see how this holds up over time as compared to a 1mm carbon rod.
You can see the access hatch in the photo above. This is where the radio receiver goes. The antenna is completely hidden inside the wing. It is run up one of the inside passages and down the other. Makes for clean looking aircraft. I used a small GWS receiver. This type of plane will generally be flown close in so a long-range receiver is not necessary.
You will notice red marks on the fuse skeleton in the completed airframe photo below. These are actually the pushrod guides.
It takes a bit of patience to get the gear assembled, especially tying on the kevlar. You need to tack it it so the knots will slide during alignment. Even with only a tiny drop, the CA often wicked through the kevlar and quickly became a permanent attachment. I found that some CA debonder loosened it enough to enable it slide on the supports. I am still aligning the gear in the photo above. There will not be any bows in the axle or support rods once it has been properly aligned.
The instructions point out that the Dubro wheel hubs have a tendancy to separate after a while, so you are shown how to fix that problem during the build. That is quite proactive on TufFlight's part.
I pushed the motor back on the stick as far as I could, and while that helped a bit, it still wasn't enough. I hated to add weight, but had little choice, so I attached .4oz of weight at the rear edge of the fuselage under the elevator. Man that's a lot of weight for a plane this size. Most of my builds are spot on, or slightly under the advertised weight. The only thing I can figure is that all of the electronic components, including servos, are forward of the CG. If the rear control servos were mounted in the rear, like many lightweight planes, this would have provided better weight distribution. It would also provide more room for battery adjustment. But, it would distract from the looks.
There was no mention in the manual about lateral balance. But I guess that if you are into 3D, you'd know to check that anyways. I did have to add a sliver of weight to the left wing to compensate for the radio and speed control being on the right. No big deal.
Our early April snow had finally melted and it was a bit gusty, but I couldn't wait any longer. I had to give this plane a try. I took it over to the field across from the house so I'd have some room to trim it out. A few clicks of the elevator is all it needed. I do think I will experiment a bit with the CG setting, though. It is a bit pitch sensative although some of that is likely related to the wind. Man does it fly nicely. I wasn't sure what to expect after I plopped it down in the field a few times. No real place to land and it is rough over there. Even though it fell on its side once, or plopped onto the gear, there was no damage. One gust caught it while I was close to the ground and pushed it down on its nose. It hit on the gear and flipped over, but no damage. None of these "landings" were hard enough to break the sacrificial motor mount. I was pretty pleased.
I decided the real test would be to see if I could "fly" it in my back yard. There isn't a lot of room back there, but there are a lot of trees. Wow! Even though this was the first time I had flown in better than 5-months, I could harrier the plane all over the yard. It really does turn in its own length. I harriered it down for landings, dropping it in the grass. Twice it nosed over, but other times it actually landed nicely, even though the wheels are quite small. I know I was grinning.
All I can say at this point is that the guys from TufFlight have made a believer out of me.
This plane is everything they claim it to be. The rest is up to me. Let the fun begin!
I learned from Joe at TufFlight that the stick mount can be shortened quite a bit to help move the CG farther aft. You just have to trim away some of the cowl for prop clearance. This enabled me to remove the weight I had added to the tail. Any weight savings always helps. As far as the stick mount, just as they explain in the instructions, once the mount loosens up a bit, you can extend its life by simply retightening the zip-tie.
The roll rate seemed a bit slow to me. So I drilled a new hole in each aileron control horn and moved the rod a bit closer to the control surface. That provided more throw. But the thing that helped the most was making sure the aileron hinge area is very thin to enable the aileron to move freely without overloading the servo.
The only real problem I've had with the plane is where the pin that holds the bottom of the cowl is attached to the lower front part of the fuse. No damage ever occurred from flying. It was just carelessness on my part in twisting the cowl out of the way to change the battery. The side force eventually cracked the fragile depron, shown by the arrow in the picture below. I simply cut a small gusset from a piece of scrap EPP foam and inserted that to provide more support between the sides of the fuse. So far so good.
I'm still working on rollers and rolling circles. But aside from those, it does everything shown in the video on TufFlight's web site. Even if I don't become very proficient at 3D flying, having the ability to grab it at any time and fly in my back yard makes it worthwhile. I'm hoping to get a few videos so people can see how it flies with a true novice at the controls. I love this plane!
I can be reached at dharbula (at) mdvl.net.