Posted by anatoly |
Feb 06, 2009 @ 11:50 AM | 4,869 Views
As it turns out, the pins on the mini-Deans connector will fit directly into the red JST connector that comes on some batteries. It takes a little effort to get them in there, but they do fit. Just make sure you have the polarity correct. Then you can just put some heatshrink over the joint, and you're done.
I saw this trick mentioned about six months ago here on rcgroups, so this isn't mine, but it seems not too many people know about it. I thought I would document it here in case someone else finds it useful.
Posted by anatoly |
Jan 07, 2009 @ 12:21 AM | 3,885 Views
I finished setting up the head and tail today. I wound up with about 10.5 degrees collective, 8 degrees of cyclic on the ailerons, and 7 degrees of cyclic on the elevator. I would have had almost 12 degrees collective, but had to re-adjust the swash links and servo travel limits to prevent interaction with the bearing block. Previously I had about 9 degrees collective and didn't know about measuring the cyclic. In any case I'm guessing this will be much more aggressive.
While I was at it, I noticed that the upper mixing arms were loose so I tightened those up as well. I'm surprised the whole thing didn't just explode during flight.
I also did the initial setup on the new gyro, making sure to center the servo and adjust the travel pot to get maximum tail pitch in both directions without binding. I set 50% rudder expo as recommended, and adjusted the gain.
What's left to do: replace the 190mm flybar with the 220mm, and put the lighter paddles on. Then test fly and do blade tracking.
Posted by anatoly |
Jan 05, 2009 @ 01:29 AM | 4,309 Views
Well, I still don't get enough stick time, especially with the new flight restrictions here in the DC area, so progress on improving my heli skills has been slow. I also sold my HBK2 a couple months ago, so I'm down to just the Trex 450 in this department. In the plane department, I finished a depron mini-Cassutt which is a heck of a great flyer, and I'm hoping to take it to a few upcoming indoor events this season.
With the helis, I have been stuck on backwards figure 8's for a little while, mostly due to lack of stick time and batteries; I managed to puff one of my Xcite 2200 packs, not even doing anything that demanding. I'm pretty sure one of the cells was weak and just couldn't take it. So I'm down to two flight batteries for the Trex, at least until I decide to order some more. Backwards figure 8's are progressing, but are still not very clean, so I will keep practicing until I get it right. I don't think simulator practice works very well for me in this case, because I think it makes backwards flight too easy.
Anyway, for the start of the year I decided to make a couple of component upgrades on the Trex. First, I decided to swap out my GY401 gyro for a JR D7703D, mostly because I want the constant piro rate for when my 3D skills progress. The other thing I'm upgrading is the motor: swapping out the stock Align 430L motor for a Scorpion HK2221-8v2, which I picked up used from another local flyer. I put in a new pair of ceramic bearings and got everything...Continue Reading
Posted by anatoly |
Oct 13, 2008 @ 12:11 AM | 4,188 Views
Unfortunately I just don't get enough time to fly. I had tried inverted hover a couple of times and couldn't quite get it, but kept trying and finally I can do an extended, stable inverted nose-in hover. I still need to practice tail-in and side-in of course, but that will all come in time.
Other things I did for the first time in the last couple of weeks: loops, FF rolls.
Next on the list of things to learn: backwards flight.
I had a spare half hour today during lunch hour and ran out to the park with my Trex 450 and three batteries. The goal for today was to try an inverted hover and see if I can hold it for a few seconds. Wind today was about 5-6mph.
I was having a bit of a tail drift problem so I decided to increase the gyro gain and see if that would help. It did, the tail was holding much better. I had the soccer field all to myself for the first pack, so after warming up with a few high-speed figure 8s and circles, I hovered it about 40 feet up and pulled back on the elevator. When I centered the stick I was inverted, and somehow not quite level so the helicopter started sliding sideways to the left as I input negative collective. I quickly pushed the elevator forward and flipped it back over to gather my nerves.
Second try, I made sure I was in a level hover and flipped it. Instinctively I kept pulling back on the collective way too far, and the heli started going up inverted and away from me. Had to flip it back over again and bring it back.
On the second pack, some people had started to show up for a little lunchtime soccer. I had to move to a smaller baseball diamond at the end of the park.
Third try, I flipped it and tried to hold the collective so it wouldn't fly up, gave too little collective and the heli started heading toward the ground, inverted. My brain instictively told my hands to give positive collective, which was a mistake and the heli started heading toward...Continue Reading
I had a spare half hour and ran out to the park with the Honeybee King 2. No one around, perfect. After three months, I was feeling ready to try idle-up and I had already set up my curves. So I did a few figure 8's in normal mode, then hovered it a good 20 feet up and flip the idle up switch...
Nothing happens. Now I'm wondering: am I really in idle up? Ok, have to see if the lower half of the stick actually holds throttle, so I take it way up, and gradually lower the stick past half, and yes, the throttle holds, so I'm in idle up. I was thinking that except for a faster descent, it didn't really feel any different than normal flight mode since I was still right side up. I flew around some more, did a couple of circuits, no problem.
2nd pack. I take off, put it in idle up pretty quickly, and do some more fast figure 8's. I'm really trying to make them look good and smooth, moving the tail just the right amount so that it looks like I'm flying, not just sliding around the sky sideways. Then about half way through the pack the nerves had subsided and I was feeling pretty brave. I decided to try a flip.
I was thinking about how I did them in the simulator, just apply power, pull back on the elevator, and when it's upside down apply some down throttle. I figured what's the worst that could happen? I've already rebuilt it a handful of times, what's one more? I took it up about 40-50 ft, goosed the throttle a little, brought it back down around center and pulled back on the elevator, then gave it some negative pitch when it was upside down and... bingo, I was right side up again. The only problem was that the tail didn't hold very well, and I wound up with the tail facing about 60 degrees left instead of directly toward me. But that was easily recoverable. I will just have to play with the gain settings on the next flight and maybe upgrade to the 43T tail gear to get better hold.
Posted by anatoly |
Apr 14, 2008 @ 01:10 AM | 5,438 Views
Ok, so I scooted my HBK2 around the floor for a little while, felt comfortable with that, then decided to see if I could hover a little bit in my basement. I pushed the throttle enough so that the skids slowly lifted off the ground, then the training gear. I got a couple inches off the ground, trying to hold it steady, and found it drifting toward the couch, or toward the fireplace, or toward the wall. The nerves definitely hit me. Maybe it was flying in such a confined space, but I haven't had such a case of nerves since my first airplane flights. I had to quickly set it down. I took a couple more hops and each time found it difficult to control the heli low to the floor. I just thought of the lesson from RADD's: just set it down and calm down. Well, it took about half an hour for me to calm down enough so I could feel how tired I actually was at 1AM and that it was time to go to bed.
After flying planes for two years, I decided that it was time to try a heli and see what I've been missing. I got a good deal on a used upgraded Honey Bee King 2, so after doing a lot of reading about setting up a CCPM helicopter, I decided to see if I can get it going. What I didn't realize is that despite everything I read, it would still take me about 10 hours of work to get to the point where I can even think about getting it off the ground.
Despite carefully reading the DX7 manual about which servos to plug into which channel, I still managed to screw it up and reverse the aileron and elevator channels. The problem is that by that time I had already went through the process, so I had to start everything all over, from servo subtrim, to leveling the swash, to zeroing the blades.
Setting the servo arms to 90 degrees, leveling the swash, zeroing the blades, adjusting total the pitch range should all be done in idle up flight mode with the motor disconnected and the throttle stick at half. That took me a while to figure out because most sites don't mention that you should switch to idle up. It's probably obvious to anyone who has been doing this for a while, but not to a heli newbie.
There are not that many sites that really talk about how to check the swash for proper movement. Here is one, although I think he has the elevator reversed. When I put the elevator stick down I expect the swash to tilt aft, which will cause the helicopter to pitch back,...Continue Reading