grounding the boom

[jgoodwin]

Bob, perfectly said. Let's hope people listen.

J

[W4DJW]

Originally Posted by Finless

...So bottom line in my opinion if you are having radio shut downs, twitching of your tail, glitches, etc I would go implement BOTH of these fixes. They are simple to do and will save you money!

Bob

Well put Bob! I'm sure I have the static issue but only when the humidity is low. I was able to recreate it with the head removed and a portable drill spinning the main shaft/bottom gear in the same direction as it would normally turn under a load. It took about 1 minute before I would get zapped with a 1/4 long arc from the boom. On another day, when it was raining, I couldn't reproduce the spark at all.

After mounting the Spektrum Flight Logger to the helicopter I have found that I get 1 frame loss for every tail jerk. On the Spektrum receiver It takes 45 contiguous frame losses before a hold will go into effect. I'm sure the receiver is not locking up or rebooting in my case or the flight logger would indicate a higher frame loss.

BTW: This forum is a great source for information! I do believe it makes a lot of people more successful at this hobby and that is wonderful for all, the enthusiasts and the suppliers alike!

Thanks for all that you do Bob and others. You have saved me tons and at the same time help keep the helicopter manufactures and distributors going strong!

[lesodell]

so finless are you grounding your helis ?

[mk1spitfire]

Well debated and put as usual,Rock on Bob.

Score line so far,

Sparks 1 Vs Noise 1

Winner plays

No bonding at all !!!!

[Aberdeen]

For the people who are hell bent on grounding their boom, and or bearings
I suggest your read this:
http://www.trextuning.com/forums/showthread.php?t=6883

topic; the nitty gritty of belt static.
make sure you read the next post regarding an edit.

[Trex mad1]

I was just going to buy an extra servo bracket and attach the wire under that to ground to the frame. I recon that would do with a metal tail box

[Finless]

Ummm explain to me how grounding the bearings is going to cause them to pit?
I am going to call a little BS on that one as pure speculation.

If no build of of potential can happen your NOT going to get arching inside the bearings as the belt never got a chance to build up a potential to cause an arc! Think about it....

I am curious as to why you think that only your ESC fix is needed to solve ALL problems. Others have clearly proven static to be an issue even on other helis! Go look at the Mikado forum here is a sticky there too.

Bob

[rcboosted]

Originally Posted by fixxxer

Likewise I presume that running the metal tail unit will suffice in regard to the rear pulley as long as the boom is sanded at the end which would then only require the front pulley to be done ?

Correct or complete crap ?

Thanks.

Originally Posted by Finless

Yes it should. Just double check continuity from the rear pulley to the frame to be sure you have a connection.

Bob

But if I have metal pulleys front and back, shouldn't they have a connection? It's metal tail shaft -> bearing -> metal tail case -> boom -> boom clamp -> frame -> metal tail drive gear mount -> bearing -> metail tail drive pulley. This takes care of the ESD. Then we gound the frame at the motor mount to negative esc to take care of potential motor interference.

In another words, for people with all metal CF heli, only the ground to motor and - is needed?

[Socal500]

Ok so I could say that if I had a metal tail casing, metal boom, metal pulleys, metal boom block that I am going to get arching in the bearings.. correct??? I understand that in that situation you have more sufraces grounded together and that grounding through the bearings you have that direct path, but what is going to ensure no arching at the bearings the the all metal situation.

[Finless]

Understand how a Van De Graf generator works.... Static build up from a belt gets stored in an ISOLATED storage tank. The combs near the belt are wired to this container. Just the belt itself is probably not capable on it's own to build up enough of a potential to do anything significant. What a Van De Graf does it pick up the low level static charge from the belt and store it in a large metal container. This build up of potential in the tank is where things get large with a high voltage potential.

So having metal pulleys, metal boom, and metal tail case BUT the entire tail system is isolated from the frames (like the 500 tail boom mount is) then the entire tail is acting like a storage container.
This allows the boom system to develop a potential OVER the frames or rest of the heli including electronics!

Now could you get buy with a metal tail case and JUST grounding the boom? Possibly and probably. I don't know for sure and it would have to be tested.

Bob

[clayboy]

but is it not just easier to use a anti static brush on the belt?

[HeliBurns]

Check this link out

http://amasci.com/emotor/belt.html

Toward the bottom, under Fig 4., the author mentions that the rollers (belt pulleys in our case) should be made of different materials( plastic and aluminum).

The implication is that if you have a metal tail drive pulley and a metal tail pulley, then the "van de graff" effect would not occur....

Bob, when you saw the heli that "sparked" at night, can you remember if the heli had a plastic tail drive pulley and a aluminum tail rotor pulley(or visa versa)?

[HeliBurns]

Isn't the isolated storage tank...the tail boom?

[Pinecone]

Also with anodized parts, you do not have an ELECTRICAL connection to discahrge through.

Notice the pics and posts with the anodizing sanded/scraped off.

[raylepper]

Originally Posted by HeliBurns

Isn't the isolated storage tank...the tail boom?

Yeah. I think that's what Bob was saying.

I think Bob pretty much nailed where we're at with this in post #59. We have two problems with lots of variables in each one. The safe bet is to do both. I'm there. Done both mods.

What's next?

[Finless]

Originally Posted by raylepper

Yeah. I think that's what Bob was saying.

I think Bob pretty much nailed where we're at with this in post #59. We have two problems with lots of variables in each one. The safe bet is to do both. I'm there. Done both mods.

What's next?

Yep and that is my point.... NO CLUE if just doing the boom is enough really so why NOT do it all?

Bob

[MoF65]

With a metal tail should the grounding be done like Gabor explained in post #11 or is it an other way to do this with the metal tail?

Morten

[Aberdeen]

Originally Posted by Finless

Understand how a Van De Graf generator works.... Static build up from a belt gets stored in an ISOLATED storage tank. The combs near the belt are wired to this container. Just the belt itself is probably not capable on it's own to build up enough of a potential to do anything significant. What a Van De Graf does it pick up the low level static charge from the belt and store it in a large metal container. This build up of potential in the tank is where things get large with a high voltage potential.

So having metal pulleys, metal boom, and metal tail case BUT the entire tail system is isolated from the frames (like the 500 tail boom mount is) then the entire tail is acting like a storage container.
This allows the boom system to develop a potential OVER the frames or rest of the heli including electronics!

Now could you get buy with a metal tail case and JUST grounding the boom? Possibly and probably. I don't know for sure and it would have to be tested.

Bob

Bob,

I just came across another thing..

Reason the 500 is so subjectable to this, the stock tail enclosure is SEALED.
therefore we have a HEAVY concentration of IONS pouring in the tail belt Drive area. where a good amount of ESD it taking place to the Frames.
Users of the metal tail assembly may notice less ESD activity.
All this is confirming my testing of electrostatic Induction: The Boom and belt is a high output concentrated Ionizer, The Frames is the Conductors and the Motor is the conductive electrostatic generator.

Quite a few users of Glass Frames Reported no problems,
if there is any users of Glass frames with these issues please report back.

Bottom line, Ground the Motor mount to the negative of the battery.
many positve effects will be obtained.

Anthony

[HeliBurns]

Bob, you lost me on you're last post...

[Dicey]

Sorry for digging this up,

But the thought is that if the tail unit on the 500 is sealed what about making some small holes in the system. That would allow the system to become open, not to a great extent, but it would eliminate the ISOLATED requirement for a Van De Graaf generator. I may be totally wrong on this, but just a thought.

Dicey