NX4 gasser interference

[Swooper6]

Hey guys, I simply wanted to share my experience of RF interference on my nx4 gasser. I first built mine in the speed build competition at IRCHA and obviously did not do an adequate job so I did commit to a complete rebuild once I returned home. The rebuild went fine and the heli idled normally for break in afterwards but I made some last touch ups yesterday morning only to find that the heli began browning out and going into failsafe every time I tried to start it up. It took me all day to find the issue but I eventually narrowed it down to the aluminum plate that I mounted to my gyro. I usually do not use an aluminum plate and instead I use three layers of double sided for dampening but I thought I should have tried it out. Anyway I found that once the plate was removed the heli continued to operate normally. My belief is that the cdi is causing RF Interference (as cdi's always like to mess with electronics) and it was bouncing off the aluminum plate right below my fbl unit. From this I do not recommend anyone using a metal plate for dampening (one of my satellites are near my fbl unit so it may have bounced to the sat). I also recommend not using a gyro that uses a metal case such as the 7200. I have Skookum on my gasser though (clear) so I do not know for sure if it would act the same with a metal case gyro, I can only assume. I hope this thread helps some people out and is at least a little informative. I pm'ed summer friends already that are building the gasser so if anyone is having anyway more direct issue please feel free to pm me and I will try my very best to lend a hand. Happy Flying!

[Hot Apple Pie Guy]

I too built mine at the gaui build off at IRCHA... Mine, I set up the skoikum on double sides sticky tape, and set my single satellite near the nose of the frame..

I was the third builder to get airborne...

It went up 10', browned out, went into safe mode, and the wind knocked it over til it hit the ground... THANK YOU safe mode! Could've been much much worse !

There is definitely something going on here with interference... But there are many who have worked around it so I'm not terribly worried...

I think I'll just try to get close up pics of Bad Gas Jr... And see where things are mounted... I witnessed that hell fly unboggable at 2700 head speed in the hands of a true pro... It was amazing, and why I'm soo excited to own my gasser!

Subscribed to this thread... Hopefully together we can sort out this gremlin. (I still haven't re-loctited mine yet...) lol

[Swooper6]

I have mine working and it flew today. On Sunday I will post picks of my nx4 setup for mounting as I have been pm'ed on it already. Hopefully that can lend a hand as I believe u have got rid of my interference issues

[Hot Apple Pie Guy]

We need to get ahold of Doug Darby... I didn't get his info at ircha... I wanna copy Bad Gas Jr's setup... Looks like it's cranking out the power! Just posted two vids of it in another thread... Found em on YouTube looking up 'Doug Darby'

[joelr]

Doug is local to me but also is on helifreak. You can message him or he might see this, or Is there a particular question I can ask him or just the component list?

[Hot Apple Pie Guy]

So, without getting longer sat wires... I mounted one on the plastic side tray near the sk540 mounting location... And put the second one on the frame side just behind the upper main shaft bearing support.. Hopefully running two and in their current locations they'll be far enough away from the CDI to prevent brownouts...

If one of them ever reads a brownout status I'm gonna get a long sat cable and run one out to the horizontal fin out on the boom...

But, my gx4 is back together and ready for breakin/final settings of servos etc...

I had to reset all the servo horns from when I built her... But haven't powered her up since IRCHA and the build off... I still need to download the sk540 software, set proper 'Gasser' thro curves... Check travels and throws etc ... Then I'm ready to start mixing fuel and burning through it!

Super excited! And a big thanks to Empire RC, GAUI, and JC Zankl for this opportunity to build a gasser at IRCHA... And TAKE it home afterwards! ;-P I owe those guys some Hot Apple Pie!! Lol

[Sowa]

The CDI shouldn't effect 2.4GHz, but it will affect 72mhz at least that's what it states in my GT15HZ manual. I looked at Mr. Darby's machine at the Remote Control Helicopter Nation fun fly, it looked like the same unit with a different spark plug wire.

[Hot Apple Pie Guy]

I had my satellite mounted up on the nose, right side, single sat at ircha... And experienced a brownout which caused a maiden hover to lockout to crash... So, there's something to be said about having sats in the right locations...

I now have one on the plastic side tray next to the skookum on the right side facing horizontally... The other is on the left rear of the frame behind the mainshaft facing vertically... And I had zero issues with sats losing signal except when I let the rx packs go down too low with voltage from idling multiple tanks...

I did fly 5-6 flights at Cmhc with no concern towards a brownout... Ircha could've just been a fluke... Who knows... But I never had a flashing sat since I set her up with two sats in different locations...

[Swooper6]

Originally Posted by Hot Apple Pie Guy

I had my satellite mounted up on the nose, right side, single sat at ircha... And experienced a brownout which caused a maiden hover to lockout to crash... So, there's something to be said about having sats in the right locations...

I now have one on the plastic side tray next to the skookum on the right side facing horizontally... The other is on the left rear of the frame behind the mainshaft facing vertically... And I had zero issues with sats losing signal except when I let the rx packs go down too low with voltage from idling multiple tanks...

I did fly 5-6 flights at Cmhc with no concern towards a brownout... Ircha could've just been a fluke... Who knows... But I never had a flashing sat since I set her up with two sats in different locations...

Awesome man glad you got yours going again! Just be careful spektrum sats don't always flash after a brown out. Happy flying!!!

[Hot Apple Pie Guy]

Yea... But the skookum. 540 definitely tells me when it gets pissed! Lol.

[Swooper6]

Originally Posted by Hot Apple Pie Guy

Yea... But the skookum. 540 definitely tells me when it gets pissed! Lol.

Haha so true

[Frostwick]

You guys are dealing with the CDI sending an EMI pulse out, which is inducing a voltage in the surrounding conductors, causing your FBL controllers to reset or brown out. Why don't you guys try shielding on the spark plug wire, or the sat cables, or both! Use a shielded wire, and ground the shielding to the negative side of the battery, or to the engine block. I'm an avionics tech in the uscg and this is what we use to eliminate interference in other systems from HF radios and radar.

[Hot Apple Pie Guy]

The cdi has a metal braided wire wrap on the outside of it... And I'm running it off a separate battery pack...

I did notice that the wire wrap is a little brittle and was starting to show some wear in areas that it rubbed so I covered over it with this plastic split tubing that came in the gaui kit...

I haven't had ANY issues since that first test flight, and perhaps it was my satellite connecting wires that were the culprit... So I replaced that, as well as adding a second satellite... No issues since then...

Bird is flying great and I absolutely love it!

[Frostwick]

Originally Posted by Hot Apple Pie Guy

The cdi has a metal braided wire wrap on the outside of it... And I'm running it off a separate battery pack...

I did notice that the wire wrap is a little brittle and was starting to show some wear in areas that it rubbed so I covered over it with this plastic split tubing that came in the gaui kit...

I haven't had ANY issues since that first test flight, and perhaps it was my satellite connecting wires that were the culprit... So I replaced that, as well as adding a second satellite... No issues since then...

Bird is flying great and I absolutely love it!

You might want to replace that shielding, and ground it again.