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Old Jan 27, 2012, 08:01 AM
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Originally Posted by jfranklyn View Post
Hello all,
I have a GT 5888 with a broken on/off switch. I've ordered another circuit board. Any tips on replacing the circuit board? I've replaced motors, batteries and skids, so I'm getting pretty good an heli surgery

Thanks
Quote:
Originally Posted by xlcrlee View Post
1. photograph where all the wires go on the "fried" PCB and/or make a detailed dwg.; put tags on all the wires, to match.

2. use great care soldering > ANY excessive heat will fry the delicate components!

Lee



note: a wise rule is: when the PCB needs replacement, get a new heli and use the old one for parts, as 2. above requires skill & technique approaching brain-surgery, and is nearly impossible to do outside the factory!
I stupidLee forgot to mention >

No one has ever reported successfully binding a 5888 Rx & 5888 Tx to each other!

The "code-check", like the fake external antenna, is a joke!

The Rx & Tx are bound together at the factory, and seem to be permanently fixed that way.

So unless the replacement PCB they ship is different from the "stock" PCB [possible, but unlikely from my experience], you'd need to order a pre-bound Rx & Tx PAIR.


Please let us know what you find out ....!


Lee
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Old Feb 02, 2012, 08:00 AM
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Noob here

Hi I am new here, but I have read this entire thread a few times. I finally managed to order two of these awesome choppers and am now awaiting delivery. I just want to thank everyone for all their posts, especially Lee for all the tuning and maintenance tips. I now have a very good understanding of what to do with these helicopters. I used to have a larger lama a few years back and have flown some gas planes in the past.

I really look forward to getting my hands on this awesome chopper. Will update once I get them. In the meantime, I wait lol
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Old Feb 02, 2012, 11:07 AM
Sir Crashalot
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I've noticed the 5888 are going up in price recently. Now it cost more to buy a 5888 than the popular FP's like the 9958 and v911.
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Old Feb 04, 2012, 05:59 AM
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Originally Posted by stonecutter View Post
I've noticed the 5888 are going up in price recently. Now it cost more to buy a 5888 than the popular FP's like the 9958 and v911.
The 9958 Blade mCX clone is slow like the original and cannot be tuned like the 5888. The v911 seems to fly well .... but I personally prefer the solidity and LOOKS of the 5888, which flies similarly when tuned & adjusted. AND the charging features [wall charger].

One of each ....?
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Old Feb 04, 2012, 06:08 PM
Sir Crashalot
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The 5888, with its hefty mass, certain provides a unique flying experience. I can't think of a comparable 4-ch metal micro heli, coax or otherwise. Only drawback of the 5888 is that it still uses built-in batteries.
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Old Feb 06, 2012, 04:33 PM
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5888 question about wobble in lower rotor blades

Hello all,
I appreciate all the posts about tuning the rotor blades. I have a 5888 that I just got back into flying shape. new motors, lubed rotor shaft and all bearings. I've fixed the tracking in the upper rotors and have them tracking in a nice even line.

The lower rotor blades wobble all over the place. This makes the heli vibrate quite a bit. I've tried to loosen/tighened the blades, changed to new blades. re-tightened all screws. Any tips on how to fix this would be greatly appreciated.

Thanks
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Old Feb 06, 2012, 04:47 PM
Sir Crashalot
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jfranklyn, if you have the time, search this thread for all of xlcrlee's posts and try to digest them. Lee is very technical and some points may be over your head (well, mine any ways). But the main thing is to adjust the blade holders angles relative to the shaft so that you see only a small span when spinning up. This is harder said than done sometimes, I use small pliers to bend the metal holders very minutely to try to tune the blades. It certainly takes patience and perseverence. I have asked Lee to make a video, but he doesn't have the equipment or convenient internet.
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Old Feb 07, 2012, 08:44 AM
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I really appreciate the update on replacing the PCB. I would have wasted a lot of time swapping, soldering, only to end up with another non-working heli. I'll use the broken one for parts and practice tuning the rotors on the working one I have flying now. Thanks
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Old Feb 09, 2012, 06:51 AM
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very Good Answers .... everyone!

b.t.w., I used to use a pair of tweezers to micro-bend the alu plates IF required, but now use two butter knives at right angles to the blade-holder plate, flat, one on top, one below the plate end, with handles pointed oppositely, of course.

FURTHER, it is often easier to apply a micro-layer of CA gel and sand/file it flat & smooth to adjust the blade fit and corresponding "tip-play".

And don't forget that coning angle of EACH separate blade is important: separately for tracking and collectively to incr/decr stability and control effectiveness [incr, coning angle DECREASES stability and INCREASES control effectiveness, although TOO much coning angle on the lower rotor will actually decrease control effectiveness].

I find that testing by using bits of clear tape on the T.E. of each blade, one at a time, near the root shows which blade needs more or has too much pitch, and at the tip shows which blade need more or has too much coning angle.

Try swapping blades left-right, and swapping links left-right: often works!

When the L.E. of the blades of the spinning rotor disc form a razor-sharp white line, you'll hear a definite jump in acoustic pitch [RPM!] and in performance. And the parameter is as sensitive as a razor-sharp knife > a knife-edge may LOOK sharp to the naked eye, but the really sharp knife works totally different. In the case of the blades' L.E., the white L.E. becomes very clearly sharp and whiter when, and ONLY when, perfectly tracked! Please trust me on this.

Lee
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Old Feb 10, 2012, 02:24 AM
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Finally got my choppers :D

Yay, so I finally got my choppers yesterday. And they are both awesome right out the box (obviously some model train lube first) and only required some minor tweaking later. I seriously love these things.

And thanks to the posts here, I know how to maintain them in great running condition. I also learnt a lot about the Lipo's and how to look after them.

Ok, I'm going to go fly again now
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Old Feb 11, 2012, 06:53 AM
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adjusting control authority/sensitivity

In addition to changing [incr/decr] the coning angles as mentioned above, it is also possible to change the effective moment arms of the swashplate >

Note: the total amount of servo throw varies from PCB to PCB [one gets what one pays for, sometimes] and is independent of the actual servo. In many cases one servo has more throw than the other: swapping servos won't change this.


Simply use electric hairdrier heat to help you BEND the arm at the "elbow" [shield the rest of the heli from the heat!]:

the more vertical the thinner end of the swashplate arm [approaching a 90 bend], the shorter the effective moment arm and the greater the movement and sensitivity of the swashplate.

the more horizontal [approaching a flat non-bend], the longer the effective moment arm and the less swashplate movement and sensitivity.


Lube and unsnap the ball joint. Hold the unconnected parts together and note the vertical & sideways position of the swashplate. Heat the arm for 7 - 10 sec, and hold bent for 2 mins.

Before re-snapping together [note: the hole on only one face/side of the link is large enough to accept the ball!!], screw the adjustable end of the pushrod in/out so that the swashplate winds up in its previous position.



Lee
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Old Feb 11, 2012, 07:12 AM
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Originally Posted by stonecutter View Post
The 5888, with its hefty mass, certain provides a unique flying experience ....
Since G.T. simply cannot spend the time and money to fine-tune & adjust these helis, there is extra power built-in [and hiding] to compensate for all the manufacturing inexactitudes.

By carefully following my tips and super-tuning these, using lots of patience and little luck, one winds up with a heavy heli with super-extra power [not 100% always, since there are always a few "duds", but over 90% of the units]. I have one heli which is good and flies very nicely [faster than posted videos] .... and FIVE others which are little rockets, hopping around almost like SRs and small CPs. And still very stable [unless pushed to their max speed and control limits -- at least 2x so fast as you might believe for such a small coax -- in whch case a lot of finesse is needed: if they were fullsize jet fighters, the computers would make the control much easier]. What I mean is that with only small amounts of power and control they behave sweetly, but beyond that, more like F1 racers, ready to "get away" in the corners, spinning in or flipping over. But I have adjusted them that way and I really do LIKE that kind of reasonably realistic "scale" action ....! > http://www.rotaryaction.com/pages/birdsprey.html

Anyway, they can fly "normally" in the slow mode.

Lee
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Old Feb 25, 2012, 06:02 AM
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GOOD NEWS > Update

I just bought from Marcel two user-returned 5888s to fix or use for parts .... and ONE Tx!

These are the latest, with bare-metal flybars.


It turns out that G.T. changed something in their chips, and at least with these [and maybe some prior models] .... it is now possible to bind & re-bind various 5888 Tx's and Rx's!! But I assume it must include the latest Tx's too. Dunno.

As per instr., one pushes vertically down on the rt. stick, then turns on Tx. Marcel did it and it works.

Anyway, this is good news ....


Lee
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Old Feb 25, 2012, 08:13 AM
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How much do they pay you for product promotion? Lol.
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Old Feb 29, 2012, 07:15 AM
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Product promotion? Because I mentioned that they finally fixed a stupid prdn. problem?

The only thing I've ever gotten from G.T. is advice to buy a different-type heli from them [they have MANY!] if I point out a 5888 prodn. problem! Nonetheless, the 5888 is still my favorite such coax .... [because I can make the most of them SUPER, the details of which are in my too-many posts].


Lee
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