Lockout/Brownout Problems - Static is a #1 issue

[fireup]

Ok, this post is to discuss all possible solutions to the lockout and brownout problems that some people are having with their T500. I will list all possible causes to the problem and possible fixes to avoid these issues. The list will be updated on this first post as more data comes in. I'm not saying you need to do any or all these mods as a lot of people don't have any problems at all, but if you feel you may or do have problems, these are steps you can take to try and solve it.

Static build up and discharge from belt/boom

Solutions:
- Ground boom and pulley to frame (see bob's #3 post on how to do this)

- or Use torque tube instead of belt drive

- or spray/apply Graphite 33 or silicon oil to belt on a regular basis


Rx/electronic placements
It is recommended that at all high voltage stuff(ESC/BEC/Motor wire) are kept away form low voltage stuff (Rx/Gyro)
- Install ESC/BEC in front of the motor, either underneath the battery tray or on the side frame but in front of the motor.
- Place Rx in the back and keep antenna leads as far away from the CF frame as much as possible
- If your Rx have a satellite (AR6200 or AR7000), install the satellite so the antenna is pointing 90 degrees and on a different plane than the main Rx. Spacing the satellite away form the side frame with a layer of plastic plate may also help.

Internal BEC + ESC switching noise effects voltage
This can also be due to servo current too high for BEC to handle and voltage drop for a very short time and cause brownout
- Set BEC for 6V and use step-down for tail if needed
- Use External BEC

ESC/BEC and motor noise (EMI noise)
- Ground ESC neg. to motor mount/carbon frame (Add 1K Ohm resistor in series from ESC to frame to prevent short circuit)

CF frame is conductive and amplify or transfer above problem/s to Rx
CF frame can also cause more "shadowing" effects
- Change from CF frame to GF frame.


Let me know if I'm missing something, check back to this first page for updates.

[kgfly]

Nice thread, should be very useful, thanks Fireup

This can also be due to servo current too high for BEC to handle and voltage drop
for a very short time and cause brownout
- Set BEC for 6V

The servos are not a constant power resistive load so increasing the voltage will not reduce the current and hence reduce the load on the BEC. Quite the opposite, raising the voltage will increase the power drawn by the servos and hence increase the load on the BEC. I don't think that this will help with any brown-out or noise problems unless there is something else at play here ?

[Finless]

Static is REAL.... I got some confirmation from some people I trust today that have agreed this is a cause of RX shut downs.
In fact I am thinking this might be one of the main causes of what many are seeing as random shut downs. e.g. flys fine for 10 flights then a shut down.
Static due to belt drive is not just a Trex500 problem! My eRaptor 620 has been blowing Castle speed control processors right and left and Castle has agreed this is what is causing it. On a e620 the ESC is usually mounted right near the tail drive. Electronics are all up front. Mikado has also had this issue (see attached picture below).
Other belt systems have the same problem but there is a difference with the T500.
1) Electronics are packs much closer to the tail drive system.
2) Other belt helis like nitros the electronics is all up front.
3) The T500 servo wire routing tend to go right past the tail system and an arc to a wire can cause a shut down.
For these reasons I believe eliminating static build up from the tail is required!

MORE RECENT PROOF Static Exists in the tail system



So lets see what has been posted on helifreak over the last few weeks.
These posts by people show for fact static is real and they have pretty much also proved it.

Moreflying did several test removing the belt etc and shows that static is real. This is a long post but worth reading his tests. Page 2 gets into it.
https://www.helifreak.com/showthread.php?t=58713

Eyefly shows he had static and how he proved it using a hv pen
https://www.helifreak.com/showthread...=static&page=2

Famus had static
https://www.helifreak.com/showthread.php?t=58996

Rhone shows some of his proof
https://www.helifreak.com/showthread.php?t=57683

These posts show how to fix it
Grounding the boom and belt system.
This is how I think it should be done
https://www.helifreak.com/showthread.php?t=59035

Another fix by famus who had static and fixed it
https://www.helifreak.com/showthread.php?t=58996

Here is another way by Rhone
https://www.helifreak.com/showthread.php?t=60060

In summary static is real and I am beginning to believe this is the highest reason some are getting random lock outs. Oiling the belt may solve this and for me I have made no mods and lubed my belt with silicon from day one. Keeping the belt wet like this may make the build up of static potential much less. I dunno for sure but I for sure believe static arcing is a large part of what people are seeing. Can an arc to the frame affect radio? I don't know but for sure I think an arc to a radio system components (servos, servo WIRES, gyro, etc) will probably cause a RX shut down or a glitch to your gyro, and even a servo!
Below is a picture of a logo showing a static build up arc to a 401 gyro! i have circled in red the arc area. The logo has the same isolated tail assembly the 500 has WITH electronics right at the drive area.


Bob

[ZipZap]

Originally Posted by kgfly

Nice thread, should be very useful, thanks Fireup


The servos are not a constant power resistive load so increasing the voltage will not reduce the current and hence reduce the load on the BEC. Quite the opposite, raising the voltage will increase the power drawn by the servos and hence increase the load on the BEC. I don't think that this will help with any brown-out or noise problems unless there is something else at play here ?

The thought is that you create more headroom between nominal voltage and the reset voltage on the receiver. It's actually pretty good logic.

[HeliBurns]

Bob, I would just like to know why it causes a RX to reset, rather than just be destroyed due to ESD, or go into failsafe....

I can see a failsafe and ESD destruction from static, but an RX reset?

I'm not saying it isn't static, but just that I can't see why a reset would occur in lieu of other things.....hope that spark phone wasn't photoshopped.....

At least these sorts of things will make us be very careful with our builds and the location of our electronics and routing of cables(which is a good thing).....and as a result perhaps the frequency of these incidences will be substantially reduced....

[HeliBurns]

Bob, is Align going to come out with a metal tailcase?....That would make grounding the tail boom components much easier....

[HeliBurns]

Bob, I misspoke...

Is Align coming out with a metal TailBoom Block is the near future?

[fireup]

Originally Posted by HeliBurns

Bob, I would just like to know why it causes a RX to reset, rather than just be destroyed due to ESD, or go into failsafe....

I can see a failsafe and ESD destruction from static, but an RX reset?

Well, maybe we need to make an ESD generator and find out if Rx resets or get destroyed from ESD.

If you take a look at torkboy's post, it seems he had a ESD issue. His Rx was flashing weird after the crash, then he cold-boot and it was fine. https://www.helifreak.com/showthread.php?t=61155

[HeliBurns]

Lol, Kevin...

Well now who wants to anti up the RX to be the "guinea pig"........hehehehe....

[Jason Chow]

im in the process of seeing if the frames are the corporate. i had a lockout myself. while im moving the esc up front and the electronics as far back as i can while repositioning them better, lets see if the GF frame will fix it. ill leave everything else the same. problems could be just a $43 fix away

[kgfly]

Originally Posted by ZipZap

The thought is that you create more headroom between nominal voltage and the reset voltage on the receiver. It's actually pretty good logic.

I am not convinced. If the problem is the BEC overloading and going into thermal shutdown then raising the voltage will increase the load and increase the risk of the BEC shutting down. If the problem is the BEC not regulating properly and dropping voltage then maybe, but it could easily be a zero sum game for the same reasons.

The key is that increasing the nominal BEC output voltage is likely to increase the load on the BEC and hence increase the risk of a BEC problem, even though it might increase the nominal margin for the Rx, that may or may not alleviate the failure if it occurs.

[fireup]

Originally Posted by kgfly

I am not convinced. If the problem is the BEC overloading and going into thermal shutdown then raising the voltage will increase the load and increase the risk of the BEC shutting down. If the problem is the BEC not regulating properly and dropping voltage then maybe, but it could easily be a zero sum game for the same reasons.

The key is that increasing the nominal BEC output voltage is likely to increase the load on the BEC and hence increase the risk of a BEC problem, even though it might increase the nominal margin for the Rx, that may or may not alleviate the failure if it occurs.

This is what I've notices on the Align Internal BEC. It drops 0.5V when I pump the collective. At the time, my BEC was set for 5.0V, but when I measured it, it was accually 4.85V. When I increase the BEC to 6.0V, it still only drop about 0.5V (I'm not saying it doesn't draw more current at 6V, but the voltage does drop the same amount on my o-scope). I also think becasue the ESC is also on the same board and sharing the same capacitors, that any switching noise from the ESC or loading of the motor can also add to the voltage drop and bring it down farther to the point that can cause a brownout. This voltage drop can be very quick.

[TRex888]

Originally Posted by HeliBurns

Bob, I would just like to know why it causes a RX to reset, rather than just be destroyed due to ESD, or go into failsafe....

I can see a failsafe and ESD destruction from static, but an RX reset?

I'm not saying it isn't static, but just that I can't see why a reset would occur in lieu of other things.....hope that spark phone wasn't photoshopped.....

During an ESD discharge magnetic fields are created which can affect electronics. One of the main ESD tests that we do in Europe for ALL electronic products is an indirect ESD discharge. This is highlighted by the ESD gun positioned at the VCP (vertical coupling plane) and HCP (horizontal coupling plane). The ESD discharge is fired into these planes which are bleed into groung via resistors. But the magnetic field that the planes generate as a result of this pulse is used to illuminate the equipment under test.

What I still fail to see is why so many problems on the T500. Very few reported on the T450 in comparison with the same electronics. My guess is something to do with the belt material and maybe the large amount of CF in the single piece side frames. That on going poll on GF frames vs CF frames is going to be an interesting one.

[kgfly]

Originally Posted by fireup

This is what I've notices on the Align Internal BEC. It drops 0.5V when I pump the collective. At the time, my BEC was set for 5.0V, but when I measured it, it was accually 4.85V. When I increase the BEC to 6.0V, it still only drop about 0.5V (I'm not saying it doesn't draw more current at 6V, but the voltage does drop the same amount on my o-scope). I also think becasue the ESC is also on the same board and sharing the same capacitors, that any switching noise from the ESC or loading of the motor can also add to the voltage drove and bring it down farther to the point that can cause a brownout. This voltage drop can be very quick.

Ah ha, so on this particular ESC the measured regulation is better at 6V despite the increased load. Fair enough, thanks for the insight Kevin.

[Finless]

Actually before the Trex SE came out with a METAL boom block people did in fact have static issues. years ago I saw a video of a Trex spun up in a dark room and the belt pulley up front was glowing and arcing.
When the metal pulleys and metal bearing blocks etc came out the amount of people complaining of this went to nothing.

Heliburns, I don't know the answer as to why it is not killing the electronics! The picture I show of the arcs to the gyro did not kill it. It's possible the arc is only going to a ground wire or ground of whatever component it is hitting and thus not frying anything. Maybe even an arc to the frame is effecting the reset? I don't know the answer only that static is real and has very much been observed.

Bob

Bob

[Socal500]

There are a couple of pilots having ESD issues to a greater extent going by what they say. I think one posted here. I suggested the complete grounding and they say it did nothing at all. I would like to see a video of this paticular heli run up at zero pitch with the lights off because they both say that when the spray wears off its ESD city.


Also since the Carbon Fiber frame is conductive but also has quite a bit of resistance wouldn't it be better to run a ground wire from a common point? Like the pulleys and boom to a point on the frame and then an actual small ground wire from there to the same point the ESC negative is grounded to the frame? I say that because with the frame resistance, couldnt the ESD seek a better path to ground, which might be through the gyro, servo or rx? Just throwing it out there .. it might not even be a possibility.

[Finless]

Yep... thats why I don't trust lube as a solution... How much is needed? How many times to lube? What humidity conditions? etc... Too many variables in my opinion. I am not saying don't lube the belt as I do it with silicon anyway (not for static reasons). Just saying that for me it sounds like a band aid to the real issue.

I question how well this person grounded everything? You need to make sure you can get a 0 ohm reading from the frames to the tail pulley shaft.

As for the 450 arcing video, this was 2+ years ago at least. I went looking for it but didnt find it.

BUT I have a feeling that if someone with these problems (that is having this problem) did this lights off video we might see it again.

Bob

[Socal500]

Yes I agree... I grounded completely and also still lubricate the belt. Just lubricating the belt alone concerns me when there are steps you can take, like grounding, that dont really add significant weight and are easy to do. I did somewhat question the grounding and they didnt like it so I said spray away.

[fireup]

Originally Posted by Finless

Yep... thats why I don't trust lube as a solution... How much is needed? How many times to lube? What humidity conditions? etc... Too many variables in my opinion. I am not saying don't lube the belt as I do it with silicon anyway (not for static reasons). Just saying that for me it sounds like a band aid to the real issue.

I question how well this person grounded everything? You need to make sure you can get a 0 ohm reading from the frames to the tail pulley shaft.

As for the 450 arcing video, this was 2+ years ago at least. I went looking for it but didnt find it.

BUT I have a feeling that if someone with these problems (that is having this problem) did this lights off video we might see it again.

Bob

Maybe this band aid is keeping you from having this problem.

Sounds like another ESD experiment in-the-dark.

[Finless]

Kevin quite possible since I lubed my belt before the first flight!
But I know others in our area (like Stembridge) that never have lubed and are not having a problem. Electonics placement might be the reason.... e.g. a arc goes to the frame not a component or wire? Just a guess.

However again I got confirmation from someone back east in very dry winter conditions that arcing was happening to them. I am hoping to get a picture like the Mikado one.

Bob