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Jul 24, 2020, 09:18 AM
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Jason Cole's Avatar
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Wait, how did the Altis cause a crash?
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Jul 24, 2020, 09:50 AM
Registered User
Quote:
Originally Posted by Jason Cole
Wait, how did the Altis cause a crash?
All wise men has said, it was caused by Altis without bypass.

I don't know what happend, but before the crash I had Altis issues. It didn't start normally allways and once it cut of the power immediately after launch.

I still continued flying with next battery, new 4 S cnhl 650mAh, full charge and after six minutes I lost control/power of the glider.

It came straight to the earth from 150m. Battery burned, but two cells were alive and the voltage were 3,9V in both cells.

I know, but the current went through the Altis to receiver and I should be bypassed Altis.

Altis also warned about full memory, but again wise men said it does not matter anything.

Sorry for my terrible English.
Last edited by jukka; Jul 24, 2020 at 09:57 AM.
Jul 24, 2020, 09:57 AM
RCG Admin
Jason Cole's Avatar
Thread OP
Got it, not sure if the Altis was the cause there or not. I run a separate receiver battery in my F5J plane, direct 2S to the receiver.
Jul 24, 2020, 10:42 AM
Registered User
jtlsf5's Avatar
Very simple solution to this. I use a cable that is set up to take 7.4V from the motor battery via the balance plug. My ESC has no BEC so separate receiver power would be needed anyways. Rather than the extra weight of a separate RX battery this is an acceptable solution as current receivers have a wide operating range.

If your ESC has a built in BEC you can still use this solution. Simply remove the red (power) wire from the ESC plug and secure it with tape or heatshrink (so the ESC/BEC will always be usable in the future). Altis still gets its power from the receiver, but ESC will supply no power back to receiver, as it only uses signal and ground.

In use, the balance tap cable is always plugged into the receiver, so plug the balance tap into the battery first which powers the receiver. Then plug the power plug from the battery into the ESC as normal. You are ready to go.

JT
Jul 24, 2020, 11:07 AM
Registered User
Aaro's Avatar
This is a very pragmatic solution but one should be aware that the balancer connectors are basically crap. Keep them clean and change at least once per season. I personally would solder a parallel supply from 2 cells and use some more reliable connector.

What comes to Altis as a cause of Jukka's disaster one can only speculate. My mindset and also experience with any extra joints and servo connectors in critical supply wires does not allow me having anything like those. Bypass the AMRT but also check the wire's solderings on pcb at least once per season - you might surprise of what you find. Still, we find that care and bypassing brings enough reliability, no-one uses additional power packs here.

Aaro

Quote:
Originally Posted by jtlsf5
Very simple solution to this. I use a cable that is set up to take 7.4V from the motor battery via the balance plug. My ESC has no BEC so separate receiver power would be needed anyways. Rather than the extra weight of a separate RX battery this is an acceptable solution as current receivers have a wide operating range.

If your ESC has a built in BEC you can still use this solution. Simply remove the red (power) wire from the ESC plug and secure it with tape or heatshrink (so the ESC/BEC will always be usable in the future). Altis still gets its power from the receiver, but ESC will supply no power back to receiver, as it only uses signal and ground.

In use, the balance tap cable is always plugged into the receiver, so plug the balance tap into the battery first which powers the receiver. Then plug the power plug from the battery into the ESC as normal. You are ready to go.

JT
Jul 24, 2020, 11:25 AM
Registered User
jtlsf5's Avatar
Quote:
Originally Posted by Aaro
This is a very pragmatic solution but one should be aware that the balancer connectors are basically crap. Keep them clean and change at least once per season. I personally would solder a parallel supply from 2 cells and use some more reliable connector.

What comes to Altis as a cause of Jukka's disaster one can only speculate. My mindset and also experience with any extra joints and servo connectors in critical supply wires does not allow me having anything like those. Bypass the AMRT but also check the wire's solderings on pcb at least once per season - you might surprise of what you find. Still, we find that care and bypassing brings enough reliability, no-one uses additional power packs here.

Aaro
Stock balance taps may be lower quality, but I made mine from aircraft quality parts, so I'm not too worried. Didn't buy the junk Chinese parts from the LHS.

JT
Jul 26, 2020, 12:06 AM
Modelist
Alexandr1's Avatar
Quote:
Originally Posted by jtlsf5
Very simple solution to this. I use a cable that is set up to take 7.4V from the motor battery via the balance plug. My ESC has no BEC so separate receiver power would be needed anyways. Rather than the extra weight of a separate RX battery this is an acceptable solution as current receivers have a wide operating range.

JT
Good idea))
There are some doubts whether this will lead to an imbalance in the battery?
Jul 26, 2020, 01:06 AM
Registered User
Tuomo's Avatar
Quote:
Originally Posted by Alexandr1
Good idea))
There are some doubts whether this will lead to an imbalance in the battery?
I doubt imbalance is a huge problem as long as one not fly the battery to critically low voltage.

However, I do not trust balancer plugs. Good quality ESC have very reliable BEC that are also simple to use. It is difficult to imagine what alternative system could be safer or more user friendly.
Jul 26, 2020, 01:11 AM
Modelist
Alexandr1's Avatar
Quote:
Originally Posted by Tuomo
However, I do not trust balancer plugs. Good quality ESC have very reliable BEC that are also simple to use. It is difficult to imagine what alternative system could be safer or more user friendly.
I completely agree!
I use external BEC on all my gliders.
But the idea of ​​powering the receiver from a balanced jack is very good. But we need to change them to more reliable ones.
Last edited by Alexandr1; Jul 26, 2020 at 02:07 AM.
Jul 28, 2020, 03:24 PM
The original Flying Pigs Sqd.
Up&Away's Avatar
Currently I see only the flight manager software for a PC. Will there be a version for a (Android) tablet?
Jul 28, 2020, 11:24 PM
launch low, fly high
We have found serious issues with the Altis plugs that do not make a reliable connection. If one is really diligent using a magnifying glass and a fine pin, one can modify the wiper on the recepticle plug to increase the wiper force. Look at the Altis "female" plug and compare to a high quality JR plug. The internal pin on the Altis is lacking... We have had several issues before replacing the Altis plugs with high quality plugs (as well as hard wiring the power and ground bypass around the Altis to minimize any risks). Only cost a few planes... After the modifications, everything has worked great. I have run power from the balance plug via the first two cells. Now, just use the ESC BEC.
Jul 29, 2020, 05:11 AM
Risto Hölttä - F3A/P Team FIN
Finnspeed's Avatar

Altis wiring fault analysis


First, a little bit about my background: I'm an electronics engineer working with weather station electronics and troubleshooting for 25 years already so I know something about reliable electronics and fault finding.

I fly F3A and F3P myself so this F5J scene is not that familiar but I got the Altis and ESC from Jukka for checking if I could find something. Jukka mentioned that people have been successfully using methods to bypass the Altis for RX power and thought he should have done the same.

Well, I checked the Altis PCB and solder joints first and generally the device seems to be well made and designed. I found some cosmetic issues with the display flex cable soldering but those could not have caused the crash. Solder joints of the critical throttle cables were fine and there were no signs of wire fatigue or loose strands there. The two wires had even been glued together to further improve their tolerance against bending and moving.

Then I took some pins out of the JR style connectors. At first glance they looked OK (no loose or broken strands) but further investigation under a stereo microscope revealed that actually the critical crimp is loose. The strain relief part that encloses the insulated part of the wire is good but when the wire was pulled, the strands were moving (!!!!) inside the contact crimp. A well made crimp connection is very reliable as it is air tight at the contact surfaces and therefore the contact resistance is very small and protected from oxidation. A loose crimp on the other hand can be totally devilish since it makes some sort of contact most of the time but can cut out suddenly without warning.

I checked closely only a couple of the crimps but will now go through them all to see if this is a trend.

Just to be sure I also compared to genuine Futaba servo extension wires and found those to be much higher quality in many ways. I guess the same applies to genuine JR or Spektrum wires even though I don't particularly like the bad keying of those vs. Futaba but that is another discussion. In any case, if the spring force in the original connectors was an issue and the connector supplier has been or is now being changed, then it would be a very good idea to check the crimping tools and crimp quality as well.

For reference, this is a very good guideline to checking the crimp quality:
https://www.te.com/content/dam/te-co...%20version.pdf
Jul 29, 2020, 08:04 AM
Screwing up is an art
mabrungard's Avatar
Quote:
Originally Posted by Joe W
We have had several issues before replacing the Altis plugs with high quality plugs (as well as hard wiring the power and ground bypass around the Altis to minimize any risks). Only cost a few planes... After the modifications, everything has worked great. I have run power from the balance plug via the first two cells. Now, just use the ESC BEC.
OK Joe, since I'm now getting into electric soaring, this is particularly salient to me. I'm purchasing soon.

So you're still using Altis products, but making this modification? Changing the plugs out with higher quality plugs and hard-wiring the power and ground leads to bypass directly between each plug?

I have to admit that I've not been paying a lot of attention to the quality of the servo connectors on my equipment for the past 40 years (no problems...yet), but what am I looking for in a 'quality' connector set? In general, all my stuff has been Airtronics and JR. Who are quality providers in your opinion?

Martin
Jul 29, 2020, 05:51 PM
Risto Hölttä - F3A/P Team FIN
Finnspeed's Avatar
As promised, I checked all the crimp joints of the Altis wiring and also the wire of the YGE 35 A ESC. Out of the 6 crimps in the Altis wires, two were bad, two OK-ish and 2 OK. In the bad ones the strands were loose inside the crimp. They are not loose enough to come out without some force but they move rather easily after removing the strain relief. Additionally the connectors of the Altis wiring are not very high quality as indicated by Joe W. They are not very tight and there's hardly any gold on the contact surfaces. Tin surface does not work very well if the other surface is gold.

Surprisingly, the YGE ESC wire crimps were not better at all. There were some loose crimps as well. So the final verdict from me is that there is an equal chance that Jukka's crash was caused by one of the reasons listed below:
  • Bad crimp connection in the Altis wires
  • Bad contact of the Altis plugs
  • Bad crimp connection in the ESC wire

If I used this kind of system in an expensive plane, I would do the following: Use a genuine Futaba/JR/Spektrum (whichever quality brand you prefer) wire from the ESC to RX directly but connect only minus and plus wires to the RX and ESC. Then connect the Altis device normally between the ESC and RX. This requires soldering the extra power wire (plus and minus) to the ESC and obviously one free channel slot in the RX. This arrangement effectively doubles the power wiring from the ESC BEC to the RX and also minimizes the number of contacts & crimps via the added power wire. After this modification, any of the joints in the Altis device can fail without causing a total loss of power to the RX.
Jul 29, 2020, 10:40 PM
launch low, fly high
Thank you Finn for the detailed and actionable analysis.

My evaluation had far less precision. My conclusion was similar. I've heard from others that there may be crimp issues as well. A big annoyance to me was that the pin in the Altis connector has a u shaped cross-section and appears to have less height than the same element in a JR plug, hence the issues with intermittent contact. I should have cut up the ones that were replaced to mic them to quantify the delta instead of using a pure visual comparison.


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