X9303 Internal Wire Chafing Issue IMPORTANT

[Ah Clem]

Official fix from JR:

http://www.jrradios.com/Articles/Art...ArticleID=1822 (http://www.jrradios.com/Articles/Article.aspx?ArticleID=1822)

I just spotted this on Flying Giants and RCU. I have no personal experience with the issue, but posted it from a safety standpoint (and I am a JR/Spektrum diehard) as I have not seen it here yet:

http://www.flyinggiants.com/forums/fg29/33293-x9303-users-look-here.html

http://www.rcuniverse.com/forum/m_7840717/mpage_1/key_/tm.htm

[WillJames]

Thanks for the heads-up. I will be checking my X9303 before I fly it again.

[Mercuriell]

My DSX9 is OK (purchased in Oz) but the harness does look vulnerable fed through that small hole in the gimbal

[aristo]

just checked mine.slight abrasion had started on the black wire,i flipped the strain relief around and now my wires are running down the side and to the left of the gimble.the way it is now the wires run parallel to the pinch point.

[heli-cuzz]

Thanks for the heads up. I'll be checking mine also.

[JimLerch]

The Freak just saved me a bunch of money in Helicopter parts!!!!!!!!!!!!!!


http://lerch.no-ip.com/Heli/X9303/TN_IMGP0399.JPG (http://lerch.no-ip.com/Heli/X9303/)

Additional (and much larger) pictures here:

http://lerch.no-ip.com/Heli/X9303/

Now, the question is, what is the best approach to problem resolution. I seem to have caught mine before any substatial material was removed from the copper conductor. If I could, I would unsolder it and replace it, but that looks like a job and a half, as neither end is user friendly.

Not sure what the alternative is. (other than sending back to Horizon Hobby and joining a rehab facility)

Personally, I'd rather fix it myself. Towards that end, I think I will attempt to


Remove and replace the chaffed cable
While the cable is out, radius the plastic support
Maybe radius the Voltage regulator that is the actual source of the problem.. I think there is plenty of material to grind away while not compromising the silicon inside.. (worse case I replace the voltage regulator with another from stock, which I actually have on hand. Maybe I'll go grind on a loose one first :o )
What I'd LIKE to do is relocate the voltage regulator.. Simply moving it up into the vacant circuit board space about an inch would resolve all these problems.. (They, are going to make me warm up my home made re-work station, I can see this coming! :roll: )

[WillJames]

Not sure what the alternative is. (other than sending back to Horizon Hobby and joining a rehab facility)

That is funny Jim. Good thing you opened the back.

Thank you for the GOOD very clear photos so we can figure out if ours are doing the same. Popping open a radio is not something I normally do so I am kinda dreading it.

[DominicD]

Hmmm, my xp9303 is fine, wonder if it's x9303 related.

[Ah Clem]

HFG,

From what I have read on the RCU and FG threads, the problem appears to be solely with the X9303, due to an additional board on the 2.4 version to which is mounted a voltage regulator (the part that the wires actually rub against).


Will,

Thank you for making the thread "Sticky". I do not actually own one of these radios, but I know so many people who do and was very concerned with this from a safety aspect.

I firmly believe that these are excellent radios. This is a minor issue to correct that could cause major failures in the field if left undetected/corrected.

[Jason Bell]

Here is what mine looked like. Had it since december.

[Laurens]

You're right on time Jason, thats almost one heli less in your fleet...

[JimLerch]

OK, I came up with a fix and implemented it. The problem isn't so much a "PINCH" but more of a wire rubbing against a near razor sharp corner of the LM2937 3.3vdc regulator. After sacrificing a spare LM2937 regulator which I found on an old, discarded disk drive back plane, I used this spare regulator as a test subject for surgery exploration.

What I found was there is significant amounts of "Extra" ceramic (or is it epoxy?) material out near the edges of the regulator.

To implement my fix, I took a dremel with a diamond covered drum bit and ground a fairly hefty bevel onto the offending side of the regulator. I don't suggest anyone else go this far, but mostly I wanted to demonstrate how far someone could go and not cause any damage.

Once I had the sharp edge of the chip beveled, I inspected the abraded wire and found only a few strands were scuffed, and none of the strands were actually broken. So, my quick and easy fix for this was a good dab of "Shoe Goo" on both the abraded wire and the beveled edge of the voltage regulator. The hope is the two bits of Shoe Goo will flow into one blob after quickly sealing the case.

I will need to be careful in the future, if I ever need to split the case again, but I can now prepare for my daily HELI fix, instead of fretting over an RMA back to Horizon Hobby.

Here's some pictures I took after beveling the chip (again, I don't suggest going this far, but I did for demonstration purposes). Also, I didn't blow the dust off for these pictures, as it made it difficult ot see how much I ground the chip down.

http://lerch.no-ip.com/Heli/X9303/Fix/

Here's a thumbnail from the page:
http://lerch.no-ip.com/Heli/X9303/Fix/TN_DSC02270.JPG

[JimLerch]

Here is what mine looked like. Had it since december.

WOW!!! I've only had mine since early April '08. If that wire broke, you would end up with full aileron deflection with no hope for recovery! ***

I wonder how much of an ass I should be when folks show up at the field with X9303s and haven't checked to see how bad they have it? Is this problem something that warrants the "You've haven't heard about this, or checked yours yet? Well lets do it RIGHT NOW!! Here's a screwdriver.. approach??

At a minimum, I should probably print out our pictures and put it up on the bulletin board at the field..

*** So, assume it did break, and somehow you started doing stationary aileron tumbles. As the disk heads towards level upright, could one go full rudder, throttle hold and maybe manage the collective to get it on the ground? (Just thinking out loud kinda..)

[shamen222]

Holy smokes, that is bad... thanks guys.. I will be checking mine tonight...

[Pinecone]

Official fix from JR:

http://www.jrradios.com/Articles/Article.aspx?ArticleID=1822

[Jason Bell]

Yea Im REALLY glad I saw the thread and looked at mine, that would of been an expensive crash!

[bullaculla]

Thanks for the heads up! I will be checking mine.
:thumbup:

Official fix from JR:

http://www.jrradios.com/Articles/Article.aspx?ArticleID=1822

I'm surprised that Horizon hasn't issued a recall! :shock:
Imagine if your wire broke and your heli/plank went down because if it. how long would you be like this :arggg: trying to figure out what caused it. The last thing I would look at is my radio.
Thanks for making this a sticky!

[aristo]

this is funny i looked at jr's fix and it is exactly what i did to mine last night,i was going to post pics tonight lol

[cudaboy_71]

thanks for the headsup. pinecone's link should be added to the top as well. i found the JR link by searching manually. would have been nice to have seen it earlier and saved some time.

gonna peek in my radio tomororw :confused:

[Don McCullough]

I just did the mod on my X9303. However, I doubt this is a problem with Mode 1 as is mine. The aileron wire goes under the throttle friction device and cannot get near the offending component. Still good to check.

Don

[cudaboy_71]

add another to the list. mine is/was affected.

and, i'm not too sure about JR's fix either. routing the wires as suggested is simple. but, there's still some interpretation left as to exactly where the wires go from JR's small photos.

what i discovered is that if i route the bundle so that the chaffed portion of the wire sits closer to the aileron gimbal as in their first photo....

http://www.jrradios.com/ProdInfo/Articles/1822-shot7.jpg

the lower right portion (when looking at the photo) of the gimbal actually gets hung up on the wire at full deflection...so much so that there is added tension on the sticks near 100%. you can actually see in their own photo where the gimbal will pull on the wires.

and, if i route the wire such that the gimbal does not interfere with the wire as in their 3rd photo from the top

http://www.jrradios.com/ProdInfo/Articles/1822-shot6.jpg

the chaffed portion is still extended out where the regulator chip can chafe. :thinking

i've tried to route them so that there is neither binding on the gimbal nor chaffing on the chip. but, there's no way to tie down the wires with the recommended fix...there's still some wire freedom that will allow them to adjust over time. i'll be checking this again in a couple of weeks.

[WillJames]

How hard was it to open the radio and get to the issue for us that are kinda iffy about popping open a expensive radio to do some mods to it ourselves Cuda?

[cudaboy_71]

How hard was it to open the radio and get to the issue for us that are kinda iffy about popping open a expensive radio to do some mods to it ourselves Cuda?

it's really the same as adjusting the tension on the gimbals. i pulled out the battery. then there's 6 screws and the whole back pops off.

the side sliders and rubber thumb grips on the sides are prone to pop off, but they just slide back into their slots.

there's also two connectors that need to be removed from the circuit board to remove the back cover completely. not mandatory to do but makes it a lot easier.

really only a 5 minute project except for not being 100% sure that their mod will work.

[fireup]

How hard was it to open the radio and get to the issue for us that are kinda iffy about popping open a expensive radio to do some mods to it ourselves Cuda?

It's just 6 phillip screws, I've open it several times to adjust the gimble tension. You just got to be careful of the battery wire that attached to the back of the case.

[Pinecone]

And the two side levers are a pain when you put it back together. :)