Read First Before Buy Double 9116 Channel RC Helicopter
Received my DH 9116 fulfilled by Amazon and it arrived on time, intact, new and everything functional. I had a few weeks experience with the small V911 4 channel, gained a lot of proficiency, but wanted something larger for outdoor flying as we head into Spring. Its a nice size, about 16" long...I haven't weighed it, but its not light so I'm hopeful that it can handle a mild breeze. It is much heavier and more substantial than the Blade 120 SR which I was shown at the local hobby store. Here are some key points that may be helpful given my experience so far:
1. I have only experienced flying ( to set up and trim) in my basement, low ceilings and limited area. Out of the box it was a bit wild on takeoff and required significant trimming to hover...2-3 bars of right aileron, 2 bars of back elevator and a bit of left rudder. I did add sub-trims for each, which do stick when TX is powered off, but they didn't seem to do much. I tried adjusting servo connectors, but that made things worse so I reset to defaults. A more experienced person may have more luck with that. Anyway, with trims, the swash is level and I can get a good solid hover at about 5' altitude. Even trimmed, you may need to be quick on the control sticks on takeoff to counteract ground effect and get it stable. Smaller 4 channel experience will help with this.
2. It is true that if you bang it around and hit stuff, the metal fly bar will hit the canopy, but this shouldn't be a problem as you get used to it and new canopies are cheap and available.
3. I removed the metal horizontal stabilizer as it is only decorative and can catch the main rotors when trying to take off. I kept the side bars on the tail boom to retain CG and add support. I cut a black 1" servo arm from airplane parts bin , reamed two holes for the screws and put that across where the horiz stab was. No more catch on start up.
4. There have been many complaints regarding tail rotor motor burning out. Mine stopped working and copter spun wildly on takeoff, of course. I pried off the plastic cage covering the motor ( lift with xacto knife behind tab locks) and discovered that a small ground wire had been poorly soldered to the motor casing. I re-soldered it and added a small piece of elect tape and it worked fine again. Check that before replacing the tail boom and motor. Caution...when testing this fix, disconnect the main rotor plug from PCB and remove the tail rotor prop for safety. The main rotors are large, fast and can do some serious damage to hands, etc.
5. Batteries. The product description and even the packaging says LiPo, but they are 650 MAH Li Ion, not Lithium Polymer which have a much higher energy density. I had ordered a 2nd when I bought the DH and wish I hadn't. This copter burns through them very quickly, airtime is very short. I bought a Thunder Power 2 cell 910 MAH 25C 7.2 volt LiPo locally and they're sold on Amazon as well. Consider, however, that the charger that comes with the DH9116 may not be appropriate for LiPo's. I wasn't about to try it, plus I have a quality LiPo charger from my airplane experience. I was able to retro-fit this battery, but it required some modifications to do so. The TP 910's JST wire is too short so I had to make an extension...easy, buy one on line, or hobby shops have male and female connectors so just solder wires together and shrink tube it. I needed about 2 more inches for the adapter. The TP 910 is similar weight, but longer, but the DH 9116 has plastic stops to keep the original batts from going too far in. Simply cut the bottom of those tabs with small side-cutters and twist off the tabs with small needle nose pliers. That give about another 1/4 inch to slide the TP 910 in far enough to get a good CG and a nice snug fit when the canopy is put back on. Also, if you're not using a balancing charger, you won't need the CSR connector which just gets in the way. I cut it off (4 wires, one at a time so not to short battery) and the 2" extension reaches the JST plug on the side which can be used for charging or discharging. The difference in power and runtime is amazing. More power response and seems to run twice as long. I'll be buying one or two more of these soon. You will be very pleased with the difference if you can set it up this way...I won't even use the two original batteries in the field.
Since I haven't flown outside to judge performance or endurance I will follow up. I can say that indoors, in a small space, it isn't nimble like a small 3 or 4 channel. The weight causes a lot of inertia and angular momentum. It won't pivot well in place without correction, but that likely won't be an issue outdoors. It also sounds great, more like a real heli, moving a lot of air with those big rotors. Has cool white LED headlight and blue flashing tail light, easily disconnected if you think it will conserve power.
Hope this helps in deciding to buy or modifying some things to make it better.
