ija

Hello All,

Does anyone have any experiences in Airtech Germany's eGear sets? especially for the size of Carf ViperJet? I cannot find too much comments from web.. If you already have or consider buying Airtech Germany's eGears I strongly recommend to read this lengthy posting.

I ordered one full set and received it lately as I trusted in the company's reputation from the "air cylinder era". Erwin's service was excellent in the beginning and mechanical quality is good but ...

Aircraft Germany (Erwin) stated by email that brakes can be used with 6-14v supply. I tested it with 2S LiPo but found the brakes very very weak. Resistance of magnetics is ~90Ohm (measured) so with full 2S LiPo braking current is only ~90mAmps. Erwin claimed it will work well with 3S or 4S LiPo even currents are small. I didn't test this yet as I don't have suitable LiPo on hand at the moment. I'm kind of hesitating 4S LiPo as it goes beyond 14v limit that Erwin stated earlier and also not supported by the controller he provided. Have anyone found if 3S LiPo for brakes is enough for Carf ViperJet size brakes with Airtech Germany system? Have anyone used successfully 4S LiPo?

THEN the really NASTY problem... I really cannot recommend AirTech Germany electric gears to anyone. I actually recommend everyone to keep your models grounded until you have done some measurements to verify if your eGear's integrated controller is same version as I received! It has potentially FATAL problem if you use your gear with 2S LiPo or with requlated ~7V! Have anyone burned your plane yet?

During first trials (maybe 30s or so) of AirTech Germany's gear actuator I used full 2S LiPo as instructed. Suddenly the gear started to move intermittently and then stopped with smoke coming out from the retract unit. Servo wire was melting and I lost also some Y-cords. Luckily Y-cord saved my receiver and the gear was not yet installed to airframe so I was able to cut supply very quickly. Please see the picture about the result here:



Apparently there was some serious internal short circuit. I emailed to Erwin about the problem and the immediate response wasWhattttt???? Airtech Germany gear was smoking and it's my mistake?? I asked what he means and the response was:and then he keeps repeating the following as a response to all emails. He also ignores all the facts:His first key point is that I used 3S LiPos... No I didn't. But apparently Erwin has some paranormal capabilities to "know" what I did!
His second and last point is that I opened the case: yes. I rolled the cover open with fingers to take pictures for him: no tools required, no seals etc.

Key point is that there is clear design or/and manufacturing problem in the device but instead of taking care of clear product liability problem Erwin starts being offensive towards me with comments like:Because Erwin denied warranty I replaced the burned servo wire just to verify the root cause was not only short circuit in poorly soldered wirings. Didn't help: it's working only partially. Then I investigated both fully working and the broken controller units more and found a very concerning fatal problem. I tried to inform Airtech Germany friendly way about it but Erwin just keeps insulting me as a result. I know one company that I won't do any business anymore.

I measured VCC voltage of Microchip controller on the eGear PCB and with full 2S LiPo it's whopping 6.25V!!! Operational Voltage specification for Microchip 12F1822 is only up to 5.5V. Microchip is not guaranteeing controller being functional with such high VCC! The system has very very BAD design mistake (or wrong component used during the manufacturing). Everyone can verify this by measuring voltage between pins 1 and 8 of the uController while it's powered with 2S LiPo.

Therefore my educated guess is the following (I cannot be sure but this is probable scenario as I didn't use 3S LiPo):
1) Microchip 12F1822 got confused/corrupted/stopped running valid code due to too high VCC
2) FETs received invalid control signal
3) wrong FETs activated simultaneously causing direct shortcut.
4) flames

Date code on Microchip PIC is 1417 (wk17 2014); this is probable to be same for the whole batch so if there was uncontrolled production variation between batches it's probable to exist at least on the boards with this PIC version.

If you are using the gears for sake of your own model's safety please check your controllers before continuing to use them (ie measure your uController's VCC). If you have this faulty version it's pure Russian Roulette when it explodes! Please remember that once it breaks Erwin will just claim that "He knows that You used 3S LiPo" which is not permitted and refuses all responsibility. Luckily I saw this before the gear was installed in the plane.

Ilkka

Carsten Groen

Ilkka,
sorry for your problems! The image is a little out of focus, are there any voltage regulators on the round board ? I guess the PIC is not supplied with the direct voltage from the servo cable ?
Would be interesting to trace the layout and form a schematic to see what's going on.
Now this is purely from the technical side of things, regarding the "customer service", I think it is better I do not comment on that (even though it is hard not to with these stupid responses you got)
PS: Thanks for the heads-up, its nice to know which companies to avoid for these products!

skywarrior

Hi,
I have a CARF Viperjet and converted to `e Gear late last year. In fact I have two Vipers all same set up in case of strife !
The only trouble I had with them is being delivered with wrong motor direction and this can be solved by treating it as a servo reverse i.e. unsoldering the board completely and turning it 180 ' then resoldering it. DO NOT reverse incoming wires. This will blow the board just like a servo because thats what it is, a servo board. I also chose elec brakes and have never had success with them. I tried 2S ,3S on/off and a H.King prop brake servo unit and an Intairco unit. None really worked smoothly which is why I wanted elec brakes. They also locked with a retained magnetism effect after landing. . I have now reverted to air brakes which work fine.

I have had over 100 flight s with the E gear and it has worked fine except I have had two brass travellers snap on the 4 mm screw thread. I keep spares now just in case. In all it works well for me and have never had any signs of your problems.
I hope you are able to sort something soon and lets hope I never have the same.

ija

Carsten, Skywarrior, All,

Please see the pictures below (hasty pictures by mobile phone hence poor quality). I can't find any regulator at all!



I made very quick test with few different voltages:
- 8.25V input causes 6.25V uController voltage,
- 8.0V causes 6.23V,
- 6,9V causes 6.2V
BUT 4,92V causes 4,1V!!!

Only one component looks like it might be a zener so probably it has some kind of zener shunt system. And my guess is that they use 6.2V Zener and everything would have been okeyish with 5.1V Zener shunt. Personally I would have used proper regulator in this kind of critical system... Anyway, I will have to create my own control system to replace this and therefore I'm not going to continue reverse-engineering this system. Luckily this kind of control is rather simple to implement better way.

Skywarrior, I would propose that you use at least separated power source for the gears and that way you could avoid total radio black out if the worst happened. It might be that your controller is different batch and works correctly: you could measure it to know. But if it has worked for long time then you are probably ok. ...The response you gave regarding to the brakes was kind of anticipated but anyway disappoints me even more

Regards,
Ilkka

Tuggs

I've dealt with Erwin Tratz before and he is indeed a difficult guy. Easily to upset and sometimes his reactions are somewhat childish. However I think its a bit harsh to judge him or his products solely because of what you described here. No offense, but there are always two sides of a story. Of course I do not want to put your word in question, but maybe you really made a mistake which led to the burned controller. I once fried a behotec e-tract (simply because I did something stupid).

His retracts are proven to be working well and his customer service is great despite of his, lets say, manners. So i hope you are really 100% sure before you put someones reputation in jeopardy.

/T

ija

Tuggs, I understand your comment very well. I was also very polite towards Erwin regardless his immediate rude responses to me. I can believe that he sees lots of user errors too, every one selling consumer electronics / RC stuff see. However he kept ignoring all the facts: ie didn't respond to direct questions and didn't explain failure mechanism at all. Just kept repeating "I know what you did! No warranty". This is not acceptable customer service.

Also I'm embedded systems specialist with almost 20 years of professional experience. I do know that I used 2S LiPo properly, not 3S like Erwin claims without investigating burned device.

And yes, I'm very careful before posting this kind of things. I also gave an opportunity for Ercan to do it by himself! I wrote this only because the controller I received from him is a fire hazard and might cause nasty accidents if shortcircuiting receiver battery during the flight or causing onboard fire. Erwin was also denying clear design/manufacturing problem that is not just with single piece but with many: I have 3 pieces. Everyone can also verify it by measuring the voltage mentioned above but like I said this might be batch specific so people need to keep it in mind like I wrote.

And regardless of the actual fatal HW issue the "service" is simply unacceptable for the gear I paid 1400EUR and I'm very happy let people know about.

BR, Ilkka

Turbotronic

Not quite, this incompetently designed product is useless and dangerous.
Not a remote chance of it being a user error.
Sorry. .

Tuggs

IIkka,

as I said, I did not want to put your competence in question. I hope you will manage to receive some form of warranty service (if Airtech realizes that the mistake is on him)

Send him a link to this thread I am sure he will be more cooperative.

ija

No problems! I didn't take it that way - we just don't know each others so wanted to tell about my background

I've already provided much more details (than in this thread) about the problem to Erwin and he has ignored everything totally. He also promised not to respond to my emails anymore while stating that I've lost the warranty. And actually when I saw the quality of the controller board, I don't care about the "warranty" anymore: if I received new boards I would not dare to use them. I'm sure Erwin hears about this thread even I didn't post this to piss him off but more like felt a need to warn fellow hobbyist as this is really safety hazard.

Cheers, Ilkka

George

My Feedback: (57)

It should not come to that. ^^^

There is always two sides to a story...I don't know Ilkka from anybody, but he obviously has some experience in this field; and it sounds like he was reasonable to ask for some "service", but was immediately met with resistance before looking into the details. At minimum, AT should have asked for the parts to be sent in for inspection given the specific details he was given about some components being used.

It's very disappointing to hear, I always thought AT was supposed to be a good company.

DrScoles

My Feedback: (18)

Looks like they shouldn't sell to someone who knows what the hell they're talking about. Ilja, you have been awesome with the other electronics gizmo's you've created, hope this guy listens to you. Through our email correspondence, I highly doubt you said anything abrasive to this guy.

jetpilot

My Feedback: (48)

Right or wrong ive always been told 4v to 7.4 volts on Egear, preferably 4.8V. nothing higher. I believe the units say this on the side casing. 4- 7.4
There is a harness available from Airtech for separate battery supply. pic attached.
We have 4 Egear sets in the field. One set has close to 100 flights. no issues
One set has a few flights with some minor issues being sorted out. one main had to be cleared of debris in bearings. works great now.
Other sets I assume are flying with no issues.
only sold one set of Ebrakes and they were returned saying they didn't work well and I just installed them on a set of gear I have and they actually work really well. lots of force under 7.4v. I can barely turn wheel with hand. I will install on jet and test asap. im guessing the install was flawed.
I just ordered 2 more sets of Egear with larger electric motors and will have in a few days.
I have played around with these Egear quite a bit with 7.4V and never seen any issues.
Erwin is honestly a great guy. One of my favorites in the hobby business. he answers calls anytime day or night, weekends, whatever. He listens to me and my suggestions and he has made so many improvements to his gear over the last several years.
Its hard not being defensive in this business because so much is user error and a lot is blamed on manufactures. there aren't a lot of the Egear sets out there and if Erwin has not experienced the failure himself personally then he probably wont recognize it as anything but user error. he has been in disbelief over failures of other stuff but after seeing it a few times, he produces a solution. He deserves respect like everyone else. We work things out together. Listen, without these guys in this business we are very limited.

Erwin is better behind the scenes and not dealing on front lines. hes been doing this for quite some time and its hard not to de defensive in this hobby business. Plus hes German I think! lol!
I think what is being argued over is a $20-50 part. Erwin believes it was overvoltage and user believes malfunction. What is it? after reading this I still don't know.
I know that I would be willing to help. tell me what I can do to help.
Scott

George

My Feedback: (57)

Great at to see you trying help out Scott!

Now I do know Scott, he's a great person and an asset to the hobby.

rc4flying

My Feedback: (21)

I have one of the early sets of these electric gear with just above 100 flights. I have only had one brass piece start to strip out, but was caught early after about 25 flights. Changed this piece out easily and now have over 75 flights with no issues.
I presently have my gear running through a Robbe PSS 2018 regulated down to 5.9 volts. Totally pleased with the gear. I am using air on the brake system.

My friend has 22 flights on his gear with no issues.

fireblade5437

Interesting to say that the PIC chip does not limit voltage through a regulator. When I made my NAV lights I incorporated a separate 5v regulator to limit voltage to the 1275 PIC as I knew that some Rx voltages could easily be over 5v never had one PIC go bad yet and have made over 50 NAV pcb's

Hard to say cause without seeing schematic but I cannot see reg either, I would not have used a zener if that's what has been used.

Alan

ija

Jetpilot, thanks for volunteering to help. It's very much appreciated.

I actually enjoyed Erwin's excellent service in the beginning - he was able to stretch his schedules and shipped my delivery faster than he promised and he was always very responsive. Therefore the disappointment was even bigger when the troubles started.

Believe me, I know very well what means to provide these hobby stuff to people - noone reads manuals and many of us are not so technically aware. That's why I was very polite especially in the beginning even his first responses were very offensive. My understanding about the potential root causes developed during the (mostly one-way) email discussion with Erwin when I further investigated the PCB. Eventually I gave very clear error description to Erwin and I was actually blaming his Electronics design house about very bad design, not blaming Erwin. I asked Erwin to verify my diagnoses with his electronics provider. At this time I wrote that I'm not actually interested in to get any warranty replacement because the electronics quality is so horrible that I could not use it anyway. I provided the further information for him in order to enable him to understand the actual problem in design so that we could save some serious accidents in future. At the end I asked if he could somehow compensate my troubles: I left the ball for him. I would have been rather happy basically for anything, 50 euros or some spare parts for future needs, Or maybe just apologies. But no responses at all to the final diagnoses email but instead some further offences and statement that my warranty ends. Erwin is in "denial phase" to accept that there is design/manufacturing problem in the controller and refuses to accept any input. And I think people should know about the fire hazard hence my report here. See some comments inlined below:

Low voltage actually explains why you have so good success with the gear! Electronics has been designed so that controller voltage is within the operational specifications in such a case.
rc4flying: your 5.9V is also saving you: Zener shunt is not yet doing anything but the associated series resistor further drops the voltage and wires & connectors contribute also to voltage drop. Therefore your actual controller voltage is probably rather near to maximum operation voltage of 5.5V and not high enough to cause troubles. I propose not to upgrade to 2S LiPo....

It's actually 5.0 - 7.4 written now. It's a big news to me that 4.8 was preferred and we all know the reason now! Erwin indicates 2S LiPo is perfectly ok also in his video here:
https://www.dropbox.com/s/g5r3o8vymj...6_low.MP4?dl=0
It's rather common way in the industry to speak about nominal voltages (7.4V is nominal for 2SLiPo) instead of actuals so I wasn't worried. And Erwin has been stating 3S is the problem not my 2S. Anyway due to design everything above ~6.0V is real problem as then operational voltage of the controller is too high in any case.

Any of those using 2S LiPo?

Erwin indicated that it's not going to work with 2S: When I asked about weak performance with 2S from Erwin I received the following response: It seems to me that there are several versions of the brakes...

Like explained above I was not actually eventually after anything. Erwin wanted to charge me 50EUR for one controller board instead of warranty replacement. Eventually I'm not interested because I found out that the controller itself is so poor quality that I need to create my own solution anyway because I want to use 2S LiPo. Everyone who understands electronics well knows how high risk of uController malfunction is when VCC is significantly above permitted range. Of course I cannot be sure what got broken but I explained above the most probable scenario. Maybe this is not Erwin's core competence and therefore I asked him to verify the problem description with his electronics design house. No response...

There really is a very bad problem in the electronics but Erwin doesn't believe. I don't know if it applies to small batch or to every single unit but it's definetely important for Erwin to investigate it. Now Erwin has been made aware of this problem but he actively ignores it. This could eventually cause big financial hit to Erwin if he is not going to take any actions. Especially in US but also in EU product liability penalties will be very high if you knew about the problem but you didn't do anything for it. It's just matter of time when some potentially serious accident is caused due to this controller design (if this is with all the gears, not just small amount) and then Erwin may find himself at the court of law. AND our hobby is under loop of officials and they create new laws & restrictions all the time: we won't need any serious accidents to provoke further control. I want to minimize the risk of accidents regardless of the cause hense this thread too. Please talk to Erwin to take care of this issue.

Ilkka

Carsten Groen

Illkka,
That is not how to design stuff like that. I would all day have preferred a separate regulator (a small lowdrop linear) that would supply the CPU with power. Clearly from the PCB there is the CPU, 2 FETs and probably a diode/zener and nothing else. Designs like that in the company I am, would not make it thru (35 years in embedded electronics and software). Hope you get it resolved !!

ija

I totally agree and that's why I am not actually after a warranty replacement. I need a safe solution - and currently the only option is to create it by myself - sigh Erwin just need to understand this also for the sake of other customers' safety.

of course the best option would be that Erwin provides fixed Electronics version as a warranty service to me and all other customers who feel they are in risk. I have understood from earlier statements that the total amount is fairly small still. Manufacturing cost of the single piece is anyway less than 10EUR -piece even in rather small quantities.

ilkka

Turbotronic

I know a guy that has driven past red lights for many years. So you see its quite safe. He is a hell of a nice guy and must know what he is doing. Many of my friends have driven with him and has had 100% success. He never refuses to offer a lift. I will let him drive my children around one day.
Some call me an idiot but what do they know....

skywarrior

Hi,
I would add that my system has always been run via a "Powerbox Competition or a Royal", both of which are regulated as you know and I have always chosen 5.9 volt output the entire system and so far have not experienced anything like your problems. Incidentally when changing the motor direction I did notice it had Jeti servo engraved on the PB. This was late last year.
I hope you get sorted as this is a very good system when working well.

ija

Hi,

"Jeti servo" mentioned on the PCB? Hmmm. then yours is definitely different than mine: with my PCB there reads " evoJet servo'I "

Like said the voltage is so near to the highest operational voltage of the PIC that you might be lucky one and you don't see the problem. However you have also double protection: Powerbox provides actually rather advanced over current protection and it may have saved you already many times but you haven't noticed it! ...When shortcircuit happens due to wild FETs Powerbox cuts the supply temporarily and it may happen fast enough to prevent permanent damage to circuitry. ...just speculating.

It would be positive surprise if Erwin would improve the controller HW and I will eventually receive correctly designed replacement boards to my gear (all 3 of those. One is broken now but I won't dare to use the remaining two either due to this design issue). However I'm not counting on the "warranty service" anymore - I've whole winter time to create new solution of my own.

Regards,
Ilkka

skywarrior

Hi,
Sorry wrong information I have just checked again on the spare set I carry and it says EVO JET SERVO not Jeti.
Apologies all around.

Regards

David

jetpilot

My Feedback: (48)

Can you
use the harness as shown and a 4.8v battery or regulated 7.4?

ija

Unfortunately Regulated 7.4v may also blow the system at any time: Zener shunt "regulator" implementation will provide ~6.2v for microcontroller and it's way too much. I have full high voltage servo system so I won't have fex powerbox 5.9v available.

For 4.8v I would need to carry some additional NiMH battery. And due to some reason the eGear states 5.0v as minimum, I don't know reason but it also makes me wonder if there is any good battery available. 2S LiPo is my preference because I could use same for lightning and minimize wiring too. Best option might be external regulation to 5.0v. But then I would need anyway new controller board to replace the broken one. And I prefer to use the 50€ to implement new reliable solution instead of paying 50€ more to Erwin as he claims I used 3S and therefore no warranty

ilkka

jetpilot

My Feedback: (48)

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