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Lordy, lordy... maiden over!

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Lordy, lordy... maiden over!

Old 09-01-2010, 11:53 AM
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Default Lordy, lordy... maiden over!

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For anyone interested, this is really a 'what happened next' after the thread "Confused about 450 Sport Mechanical Blade Pitch Setup" where I described last week's explosive events surrounding my new 450 Sport. Thankfully, there wasn't too much damage and I got some very good advice about setting up the head correctly. I followed the other members suggestions and very quickly my difficulties were resolved. That was all last week.</p>

Then yesterday morning at about 08:00am, at Busket's Lawn in the New Forest, I had my maiden flight and, for the next 18-hours I couldn't have been happier... but I'm getting ahead of myself.</p>

I arrived there just before 08:00am with a surplus of anxiety and no real idea of how things were going to turn-out...</p>

...to explain, I have been flying a Walkera CB180Z for about 4-months. As I expect you know, this is a tiny little FP which has both a flybar and a 3-axis gyro, so should be pretty easy to control. Even so, it took me about a fortnight to teach my thumbs to make small stick-adjustments, rather than the massive over-correcting that many new flyers suffer from. Then suddenly one day, in the backyard, it was as if my thumbs had learned what to do without having to be told and there I was ...hovering!</p>

Every day since then, I have spent at least 2-hours on the sim, and... weather permitting, run 3 - 6 packs through the Walkera out in the backyard. Space is fairly restricted, I guess I have about 3m squared to play with, which is enough to practice hovering &amp; orientation, but not much else. Although, I suppose all that regular practice must have paid-off, because about two months ago I took the Walkera out to the New Forest at about 05:00am, before the sun had time to generate too much wind. On my way there it was my intention simply to practice hovering some more, but once I got airborne, with all that space around me... well... my thumbs seemed to say, "don't worry Rich, we'll take it from here" and before I knew it I was making stall-turns, doing piro's (one or two, anyway) and generally throwing it around the sky! Just like I do in the sim... I was elated!</p>

To be truthful, I did manage to crash... into myself, going at a fair old lick. I brought it down right across the back of my shoulders which hurt me, but not the heli thank goodness!</p>

I went out again a couple more times after that but each time there was a little wind and the Walkera just couldn't handle it. I could hover, but as soon as I turned into the wind it would stall, and then just hang there and was a bit tricky to get back down again.</p>

It was at this point that I decided that I was going to have to jack-it-up a bit. I spent a few weeks flogging-off unwanted items (including premium bonds) until I had just about enough to get myself a TRex 450 Sport with a DX6i radio, a GY401 gyro, a Futaba S9257 tail servo, 3 x Acer D12-MG's, a couple of fast-charge packs with charger, plus (big mistake!) a Helivol toolkit and a few sundry bits.</p>

The delivery of this box of goodies and subsequent setup issues are covered in the other thread (see above) so I won't say any more about it here. But yesterday morning, on the short drive out to the forest I had no idea how the TRex was going to behave compared to the Walkera. Of course, I had been flying various CP's in realflight G4.5, but I couldn't help wondering just how much similarity I was going to see between that experience and what I was about to attempt? I mean, by this time, in realflight I could hover pretty well, do fast stall-turns &amp; fly-pasts, even fly-past inverted and subsequently recover and land... I was starting to feel a bit more accomplished... but a sim is not reality... is it?

As it goes, I had already had a bit of a battle of nerves while deciding to even go out there. There was some sign of wind and I could just see myself driving home with a bag of expensive junk and a large repair bill! I umm'd and arr'd for about an hour until I'd nearly missed my slot (the quiet time early in the morning before all the dog walkers show up). Finally I got a hold of myself, packed-up and set-off.</p>

As I arrived, there were a couple of blokes setting-up for a bank holiday cricket match so rather than using their nice flat cricket square as I'd hoped to, I was relegated to the lumpy, rabbit-cropped, horse-manure bedecked forest turf with all of its ups &amp; downs and pits and bumps. There was also about 8mph of cross-wind gusting to around 13mph. Nevertheless, 'this is it' I thought. 'I cannot back out now.'</p></p></font><font lang="ZH-CN" size="2" face="SimSun"><font lang="ZH-CN" size="2" face="SimSun">

??</p></font></font><font size="2">

I went through my pre-flight check of screws and servos, stood back and gave a little throttle. Now, since the experience with exploding woodies in my living-room (see other thread) I had become a bit didgy of the noise that the engine makes winding-up... that sharp whine ...rapidly rising in pitch... it definitely puts my nerves on edge.</p>

Even so, I give it a smidge more throttle and the skids begin to lighten... a bit more and up we go... it's a tidy lift-of with no dragging of skids or training-rig and suddenly... cor blimey mister... I'm hovering! It turns-out to be such a well-behaved and polite little machine that I can't quite believe it. I had been expecting a bag of squirrels and I seem to have a bouncy, lazy *****-cat.</p>

Granted, I'm in Normal mode with...</p>

low-rates at 85% for cyclic &amp; rudder, and</p>

18% / 18% expo on the cyclic with 10% on the rudder</p>

And my curves* are...</p>

TH: 0, 33, 60, 83, 100</p>

PI: 45, 63, 83, 93, 100 - don't worry, no intention of switching to idle-up from here! Before I'm ready to do that I'll make sure that Normal &amp; Idle-Up pitch-curves match at midsticks so there will be no sudden lurch upwards or downwards

...and Normal mode is where I stayed ...and will do for some time. At present all I'm doing is tail-in and left/right side-on hovering; even in the sim, I still can't maintain a nose-in hover! My next milestone with the TRex will be to lose the training-rig. I haven't used one with the Walkera for some time now and I feel that I will probably try the TRex without during the next week or so. Once I'm happy with that arrangement, I may decide to try the transition from Normal to Idle-up and perhaps a few stall-turns.</p>

So I ran my two packs and even managed to re-charge one in the field (I've got a power-cube which will run my charger long enough to get a single cycle into a pack) and headed home heli-hover-happy. Later, that evening, I went back and did it again. This time though, I had a not exactly heavy landing, but a not so light landing which managed to loosen the tail-boom block and slacken the belt a bit.</p>

This has happened more than once. That stock, plastic tail block doesn't seem to hold the boom too well? I plan to replace it with the metal upgrade but have to wait for funds. Meanwhile, I had already bought an rc-screwz stainless-steel set and have been working my way through, replacing the dubious stock screws a few at a time. Since the tail-boom block was already loosened, it seemed like the right time to replace the four screws on the left-hand side (the right-hand ones are underneath the second Rx).</p>

It's always the way... I replaced the first three screws without any problem, came to the fourth and wham, without any warning the hex slot rounded-out and suddenly I've got a stuck screw! I tried everything I could think of with the tools available but nothing helped... the screw is stuck fast and by now there isn't much head left! So I've ended-up ordering some drill bits 1.0mm / 1.2mm / 1.3mm and an easy-out style tap-wrench and reverse-thread taps. They haven't arrived yet and I know they can cause more problems than they solve but at the moment, my only other option is to cut through the boom-block and the screw, just inside the frame which will mean getting the upgrade block first. As things stand I can still fly my heli so I'm gonna leave it until I've had a good practice using the easy-out kit. I've got a load of the stock screws left-over after I replaced them with the stainless ones. I'll screw a few into a wood block and see if I can get them out using the kit. If that doesn't work I'll have to wait for the upgrade block.</p>

All of this took the shine off the pleasure of my maiden flight. But I see a few other people have similar problems so I'm not alone. The killer is that I knew this was a risk which is why I bought the rc-screwz set in the first place! But I had no idea just how quickly Align's stock screws fail! Don't risk it, replace 'em straight away. My policy now is that THE VERY FIRST TIME I undo a stock screw REPLACE IT!!! a word to the wise.</p>

Finally, the quest for knowledge... I have a couple of questions:</p>

[Q1] The first is, does anyone have a mod for stopping the tail-boom and drive-belt from getting loose so easily?</p>

[Q2] My second question is with regard to tail-slip. As I said, I've got a GY401 and I have it set on the DX6i at 25% / 75%. I've also tried lowering the HH setting to 60% and later upping it to 80%. But still, during hover I get about 5 - 8 degrees of clockwise slip? Every time I correct it with the rudder, it stays true for about 30 seconds then starts to slip left again where it stays. I've seen the same thing on the Walkera. Anyone tell me what's going on? Is this normal, or is it a problem?</p>

That's it for now. Sorry for the screed.</p>

Rich</p></p></font><font lang="ZH-CN" size="2" face="SimSun"><font lang="ZH-CN" size="2" face="SimSun">

* I know these curves are not what Finless recommends. I got them from 'helituning.com' and they seem to suit me for now. At my next outing I will be trying-out the standard {0, 50, 80, 90, 100} and {40, 45, 50, 75, 100} a'la Finless. But for starters, given my nervousness, I thought the former seemed a bit more forgiving.</p></font></font>
Old 11-04-2010, 01:28 PM
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Default RE: Lordy, lordy... maiden over!

answer to your 2nd question... have you set your tail subtrim to stop the "creep" of the tail servo while in heading lock mode? If not pm me and i'll explain to you how to do it.
Old 11-04-2010, 02:27 PM
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Default RE: Lordy, lordy... maiden over!

I would check the mechanics of the tail. Make sure nothing is binding.  anything below 50 is normal mode.  above 50 is heading hold on the dx6i.  if your boom is sliding in and becoming loose it could explain the tail issue.

to stop the tail boom from sliding in use some <font color="#ff0000">scotch tape</font> and it should be tighter on the boom mount.
Old 11-04-2010, 06:05 PM
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Default RE: Lordy, lordy... maiden over!

I file (scratch) the boom to get it rougher at the section where it fits in the heli and apply a bit of CA glue. I have also used one layer of tape (in some cases electric tape for tail servo mount).

For the tail slip, make sure that the tail servo is mechanically centered when the tail is centered (fold the blades towards each other, and they will line up when centered).
Old 11-06-2010, 01:48 PM
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Default RE: Lordy, lordy... maiden over!

In HH you you dont set the subtrim to stop the tail from creeping. Know what your talking about before offering advice.

If your tail is creeping in HH mode try adjusting your gain up. Adjust you gian up until a bit at a time. if the tail starts to wage / hunt then you have gone to far. Another thing that can cause the tail to creep is low HS. You see it if the low end of the TC is to low in normal mode.

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