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Airtech Germany eGears (SERIOUS WARNING!)

Old 11-24-2015, 01:34 PM
  #26  
jetpilot
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http://xtcm.evojets.de/product_info.php?products_id=95
Old 11-24-2015, 02:29 PM
  #27  
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Originally Posted by jetpilot
He told me he tests every unit at 7.4. If you test a 100 units and none fail then is it ok? or just that fact the part is rate to 6V is a no go?
I have been using 7.4 myself. no issues.
The harness supplies its own power to gear. Why not simply use the harness with separate battery such as a life A123 6v? Or regulate battery supply to 6v with a regulator?
Scott
If you test every unit for 5 seconds it's not enough. How about doing some stress test for 20 units or so? Turn on/off every 10 minutes for a week and move gears maybe every 1 minute? This is very easy to automate. I'm rather sure atleast some of those will fail similar way as mine did and it's not going to take a week. Difficulty is that there will be several fail mechanism and the critical one is FET control, and you need to have both FET controls to fail same time. If something else fails, eg watchdog mechanism may be able to keep the system sane from user point of view even bad things happens behind the scenes. Please ask Erwin to discuss to someone with real professional experience on high speed electronics and he/she will explain Erwin why it's not ok to use voltages beyond operational specifications. It really seems to me that Erwin is not able to understand whole thing and the fact that this controller is causing unnecessary risk to everyone; this risk is easy to eliminate: instruct everyone to use low 5-5.5 voltage or/and fix the controller.

I just had "bad" luck and it failed immediately. And my thinking is that I can not be the only lottery winner with this system. (or actually it was good luck because if it happened on the flight it could have been total disaster. It was also good luck that I had so bad warranty service from Erwin: If he had taken care of warranty normal way I would newer have checked failure mechanism but thought it was just single bad unit. If you all have good experience then it might be that I would have newer experienced the problem again but someone else would have crashed. And... Is there several batches? Maybe you have older version with 5.1V zener but mine has 6.2V zener by manufacturing mistake? Then all with new gear are really in danger? Have Erwin checked this option?

Also Erwin "knew that I used 3S" as an immediate response... my guess is that this happens rather often. I don't believe all of those were so stupid that they really used 3S!

Very clearly Microchip PIC works somehow even with 6.25V because testing has been succesful. But it's not reliable with such a voltage because if it was then Microchip would surely rate it for higher voltage. Controller may fail every now and then and reboot itself but noone notice, or IOs may fluctuate somehow but not enough to always cause visible troubles. BUT for me it caused a problem: either firmware execution got corrupted or/and IO cell failed so that it forced FETs in short circuit. Of course there could be other failure mechanisms also but this sounds very potential to me because of the very clear design/manufacturing error.

Full A123 voltage is too high also but sure regulating down is an option; 5...5.5V target probably the most safest ones with this. But Erwin has stated that I have no warranty because he claims that "He knows I used 3S" and therefore I should pay him more to get replacement PCB. It's cheaper for me to create new solution and then I can freely use 2S LiPo without worries. (and I like building gadgets so this is not a really too big hurdle for me..)

(And if there was working controller PCBs on hand it's much easier to swap the zener on the PCB to 5.1V or so - no need for external regulators. even though zener-shunt solution is bad as such...). Erwin could save a lot headache just by updating this one component if he is not willing to do it properly with a linear regulator.)

Regards,
Ilkka
Old 11-24-2015, 02:47 PM
  #28  
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http://www.dreamworksrc.com/catalog/...nic-Controller

what about this?

http://www.dreamworksrc.com/catalog/...tage-Regulator

7$ regulator

No one will crash with a harness with separate battery.
A simple regulator and separate battery should be even better.

He said he test every unit for 30 minutes with 7.4 volts.

I have had mine on for hours and days and weeks. no regulator, no separate battery, straight 7.4V no issues

I have asked him to see about changing that part to higher voltage part.

Would you like me to send you a harness? or new board?
Scott

Last edited by jetpilot; 11-24-2015 at 02:49 PM.
Old 11-24-2015, 11:49 PM
  #29  
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Okay, Im no electronics guy, but what is this on the other side?. Is this a resistor? or Diode? its the black piece standing upright.
And that tan block. Diode?

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Old 11-25-2015, 12:32 AM
  #30  
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Originally Posted by jetpilot
Okay, Im no electronics guy, but what is this on the other side?. Is this a resistor? or Diode? its the black piece standing upright.
And that tan block. Diode?

Black one is hall sensor to count revolutions.

brown one is condensator.

thanks for your support Scott, I don't need a harness. I always create my custom wires to avoid extra connectors and optimize weight. I could have use for the controller board as a temporary solution to enable me moving retracts while I build the plane. I will probably swap it later to my own solution anyway.

anyway, Erwin contacted me and gave contacts for his electrics designer. I will contact him and let's hope we will get improved controllers soonish.

cheers, ilkka
Old 11-25-2015, 05:05 AM
  #31  
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Okey... It's actually hard to blame Erwin about the controller quality. His electrics provider genuinely believes that everything is fine with the current HW.

I received fast and polite response from him:" Your testings confirmed never a voltage above 6.3V - so all ok so far." and then he referenced to Absolute Maximum (stress) ratings being 6.5V.

This also confirms that he uses ~6.3V zener solution by purpose and it's not just single batch manufacturing mistake. I tried to politely refer to Functional ratings being max 5.5V and Microchip is not guaranteeing functionality beyond those.. then he responded nicely:"Thank you I can read Mr. Clever".

It's rather clear that there is now an electric system designer who clearly doesn't understand how to read datasheets and therefore I know now one company where you really cannot trust on Electronics quality. If the designer doesn't understand the difference between Absolute Maximum ratings, Operational ratings and associated warnings in the datasheet I really doubt the overall quality of the products... But since I haven't bought anything from him directly it's not my business. This discussion seems as dead end. Everybody can draw their own conclusions I tried my best.

Ilkka
Old 11-25-2015, 05:20 AM
  #32  
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Hi,
Does he design their turbine electronics as well ?
Old 11-25-2015, 08:18 AM
  #33  
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Originally Posted by skywarrior
Hi,
Does he design their turbine electronics as well ?
I don't know.
Old 11-25-2015, 11:15 AM
  #34  
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What's nominal voltage rating on the Microchip IC? Industry standard is +/- 10% VCC for all physical design rule checks at tapeout and also later for characterization. Beyond that on the high end you risk electromigration(hold time checks could fail too on the sequential logic etc, list goes on).

Last edited by dbsonic; 11-25-2015 at 11:22 AM.
Old 11-25-2015, 11:27 AM
  #35  
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Originally Posted by dbsonic
What's nominal voltage rating on the Microchip IC? Industry standard is +/- 10% VCC for all physical design rule checks at tapeout and also later for characterization. Beyond that on the high end you risk electromigration(hold time checks could fail too on the sequential logic etc, list goes on).
Absolute maximum Ratings for VCC (for stress test only, functionality not guaranteed but no physical damage to the device) is -0.3V ... +6.5V
DC Charasteristics (Operational conditions ratings): 1.8/2.5 - 5.5V depending on the used frequency.

I don't know Microchips internal VCC design targets.

Ilkka
Old 11-25-2015, 11:57 AM
  #36  
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I suspect hold times and other functional DRC on sequential logic checked only up to 5.5 volt best case(FF) corner is what that says. Basically, depending which part of the wafer process distribution the die comes from it may operate "flaky" over 5.5v.
Old 11-25-2015, 12:46 PM
  #37  
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Originally Posted by dbsonic
I suspect hold times and other functional DRC on sequential logic checked only up to 5.5 volt best case(FF) corner is what that says. Basically, depending which part of the wafer process distribution the die comes from it may operate "flaky" over 5.5v.
Yep that's my guess too. Even if the public documentation had some 10% safety margin it would mean 6.05V. And this eGear system is running with 6.2-6.3 by design.

As a result noone can trust on the sw execution at all, potential problems may be hidden long time due to watchdog etc but when **** hits the fan wrong FETs gets invalid control signal and we have a fire. I didn't even try to explain process verification facts for the persons in question as they really had a thinking that it works perfectly in their own tests so there can't be a problem. LOL.
Old 11-26-2015, 01:40 AM
  #38  
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Thanks for the report Ilkka, that is a classic "Mr know it all" attitude from this guy, guess he skipped class when datasheets and specs was on the menu.....
It is very very bad design, it would only be a few cents extra to included a proper linear regulator in this design.

Originally Posted by ija
Okey... It's actually hard to blame Erwin about the controller quality. His electrics provider genuinely believes that everything is fine with the current HW.

I received fast and polite response from him:" Your testings confirmed never a voltage above 6.3V - so all ok so far." and then he referenced to Absolute Maximum (stress) ratings being 6.5V.

This also confirms that he uses ~6.3V zener solution by purpose and it's not just single batch manufacturing mistake. I tried to politely refer to Functional ratings being max 5.5V and Microchip is not guaranteeing functionality beyond those.. then he responded nicely:"Thank you I can read Mr. Clever".

It's rather clear that there is now an electric system designer who clearly doesn't understand how to read datasheets and therefore I know now one company where you really cannot trust on Electronics quality. If the designer doesn't understand the difference between Absolute Maximum ratings, Operational ratings and associated warnings in the datasheet I really doubt the overall quality of the products... But since I haven't bought anything from him directly it's not my business. This discussion seems as dead end. Everybody can draw their own conclusions I tried my best.

Ilkka

Last edited by Carsten Groen; 11-26-2015 at 01:43 AM.
Old 04-17-2016, 11:27 AM
  #39  
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Howdy,

I don't know if I should cry or yell but this whole story seems very surrealistic to me... I'm just integrating replacement solution and opened also "still working gears" in order to replace the control PCBs: And wholy crap what I found!

Damn Airtech Germany sold me some prototype stuff!! ALL 3 controllers are different kind. please refer to the picture: two with solder mask but different kind of FETs and one PCB has not even solder mask! ie. probably from the very first proto round. (which I find kind of odd as I don't know any good reasons to omit solder mask with today's PCB prices...)



Also while testing the replacement solution I found out that the sensor magnet of the failed gear was totally dead! So this means that the controller didn't get any pulses and it had to rely on current limit to stop at the end. In addition to very questionable HW design it might be that the root cause was actually the broken magnet and then current limit feature was not working correctly and whole thing burned. Just guessing (as the motor survived...) Airtech Germany claims they test everything but it's fairly difficult to believe... Be careful out there if you are using their stuff! They apparently sell expensive untested prototypes without warranty.


And last but not least: one capacitor on the "proto PCB" has been totally destroyed while soldered or handled. This gear was working though:



Now I also know why Airtech Germany dude got angry when he heard I opened the case... He didn't want to reveal what was sold.

I will update you soonish about the improved replacement solution.

Ilkka
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Old 06-12-2016, 11:54 AM
  #40  
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Howdy,

Xicoy saved me great effort by introducing a nice drop-in replament. Even Airtech Germany ignored their warranty duty I didn't eventually need to create my own solution, thanks to great Xicoy's solution. Works perfectly with Airtech Germany's motors & mechanics:

http://www.rcuniverse.com/forum/rc-j...l#post12223719

Cheers, Ilkka
Old 06-13-2016, 01:17 AM
  #41  
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Ija,
I had the "pleasure" to work with two brand new mechanisms this weekend! The moved the wrong way as compared with the original nose gear. Answer was just to rotate the control board! So, my friend got me to open the engine and turn the board around. To my (big) surprise, the PCB was just a raw PCB with no solder resist etc on it, looked like a prototype board (even though they were both brand new!). Amazing how one can sell stuff like that
Old 06-13-2016, 08:28 AM
  #42  
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Originally Posted by Carsten Groen
To my (big) surprise, the PCB was just a raw PCB with no solder resist etc on it, looked like a prototype board (even though they were both brand new!). Amazing how one can sell stuff like that
So it wasn't just me: I found every single pcb of my gears were different kind! See the picture at my post #39 above. One being raw PCB like in your friend's case. My boards were also soldered with leaded solder being against EU regulations but that's the only thing I'm not complaining about as it made much easier to swap the boards to Xicoy ones . It seems to me that I won't get surprised nor disappointed just about anything after seeing all this...

Ilkka
Old 06-13-2016, 10:26 AM
  #43  
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Hi
so having changed from Elec brakes back to because of disappointing performance I still retain the e units which seem to work fine ( except the travellers break after a while)
what spec do I ask for from Gaspar (2s 3s ) and is there a spec for the boards for these units?
I use a PB Comp SRS and I am looking to use S bus from the 7008 Rx and power from the spare plug socket on the Comp unit as it it regulated to 5.8 v
so I would prefer to match the boards to this voltage.
How does this spin to you ?
Old 06-13-2016, 12:37 PM
  #44  
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Originally Posted by skywarrior
Hi
so having changed from Elec brakes back to because of disappointing performance I still retain the e units which seem to work fine ( except the travellers break after a while)
what spec do I ask for from Gaspar (2s 3s ) and is there a spec for the boards for these units?
I use a PB Comp SRS and I am looking to use S bus from the 7008 Rx and power from the spare plug socket on the Comp unit as it it regulated to 5.8 v
so I would prefer to match the boards to this voltage.
How does this spin to you ?
Xicoy units support wide voltage & current range... It's not restricting factor at all. Airtech Germany dude instructed me to use their egears with max 2S LiPo. Motors get warm after some cycles so you really should not increase voltage beyond 2S LiPo. 5.8V regulated is probably a very good idea for retract function. It's slower than direct 2S LiPo though. You can feed this voltage from PB to LGC15's MPX connector. It's not however enough for brakes but as you said brakes are very poorly performing anyway and not in use this is not an issue for you. You will receive right encoder boards by asking Xicoy to deliver you "Airtech Germany upgrade encoders". Those are perfect fit at least to the engines Airtech Germany delivered to me for CARF ViperJet. (I don't know if there are different sizes of motors with some other gear sets)

BR,
Ilkka
Old 06-13-2016, 10:33 PM
  #45  
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Hi
thank you for the info. I also have CARF Viper jet with about 145 flights on it so far.
I only went back to air brakes because of the lack of progressive breaking on the Elec version.
If I revert to original Elec brakes :
Will these be progressive
It seems I should use separate 2S Lipo
Currently the gear is powered from the PB Comp which is fed with 2x5400 loop over nose wheel for balance as I use a 180 jetcat for power.
The current system has worked ok except as I say for brass traveller breakages owing to the lack of material at the screw thread point. I have re made these with phosphor bronze replacements which seems to have solved the problem.
so is it worth converting back to elec on the brakes ?
i currently use a small demand valve from Festo to regulate brake pressure.
I also had the elec brakes lock up at stop and pulling the plane back by hand. It is as if there is a residual magnetism still present after releasing the elec brake. After about 10secs it has dissapeared
I am also keen on the gyro steering and separated brake possibilities

Regards
David

Last edited by skywarrior; 06-14-2016 at 12:51 AM.
Old 06-14-2016, 12:01 AM
  #46  
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Ilkka,
just to confirm, the PCBs of the 2 new units was also leaded solder.
And the brakes on my friends plane is also not working any longer (since some time)
Old 06-14-2016, 11:25 AM
  #47  
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David,

It seems to me that if you had air brakes now in use it's better to stick with those really. Like Carsten wrote the electric brakes are not long lasting (I have heard also other similar cases). Due to very poor 2S braking force I'm actually in progress to try 3S separately for brakes only (as gear mechanisms won't tolerate 3S). And on bench tests even 3S is not too much better. You could use gyro steering for nose gear still.

BR, Ilkka
Old 06-20-2016, 02:31 PM
  #48  
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Default Motor board replacementw

Hi,
i have the boards and some questions

There's is is a small round thick washer with small central hole.Is this used on the CARF size gear motor
It says if the motor is revolving the wrong way for up or down then reverse the supply.
does that mean turn the board 180 so the supply is reversed to the board or ?

Regards
David
Old 06-20-2016, 09:19 PM
  #49  
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Originally Posted by skywarrior
Hi,
i have the boards and some questions

There's is is a small round thick washer with small central hole.Is this used on the CARF size gear motor
It says if the motor is revolving the wrong way for up or down then reverse the supply.

does that mean turn the board 180 so the supply is reversed to the board or ?

Regards
David
Hi David,

I didn't use any washers so I'm unsure what kind of washer you have. Please refer to the picture below to show the installation. Just make sure the board is not touching to motor casing.

If the gear motor direction is wrong just reverse the cord while connecting it to LGC15 unit: simple and no need for any further soldering.

Regards, Ilkka

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Old 06-20-2016, 10:46 PM
  #50  
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David,

The washer is the encoder magnet, you should istall as per the Picture on our website: http://www.xicoy.com/catalog/product...40&language=en

Gaspar

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