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#41 Wavess

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Posted 28 March 2008 - 11:46 AM

It would be interesting to see what happens after you add the counterpoise element (poor man's dipole in your situation).

:D Iīm not a poor man, but not a rich either, :lol: just kidding. I think this solution would be one of the last Iīd try, theorycally this has to be installated antenna to one side of the wing and ground plane on the other side, might be a bit hard to achieve it on telemaster

Since you've added toroids to the servo wires and the problem seemed to change a little, then that suggests that part of the problem is RFI coupled through, or radiating from, the servo wiring. A more aggressive solution would involve adding 10uH chokes on each of the servos' three wires, plus retain the toroids.


Do u think some cap would be needed too?

BTW, did you happen to get *at least* a half-dozen tight wraps (more is better) on the toriods, like the photo at the bottom of this page?: http://www.dpcav.com...o...=255&page=1.

Yes, I post some pics at the end of this topic, you could see some of the ferrites Iīm using (4 different kinds)

Most of your installation is a mystery to me, so it is hard to offer any particular advice. For example, R/C receiver's vary in their performance when they confront power supply and EMI/RFI noise. Also, the servos impact this too. For example, modern digital servos have very low impedance FET bridge amps and faster motor updates. This increases the noise floor in a R/C installation due to their higher instantaneous peak currents and faster rise times. That's not to say that legacy "analog" servos are free of this issue, but the point is that the new digital stuff did not help out. Long story short, the issue with glitches is affected by how and what you install.


But your expert advice is great to have.
Iīve noticed that the glicher servo is the digital pan (hyperion) but this could be understandable because it has 2 times the travel the other servos have.

If you cannot resolve the problem (that would be unusal), and the twitches are minor and do not affect flight, and your ground range is not affected, then you may want to consider a high quality PCM Rx. But, don't do that if the existing problem involves a substantial range loss with a good quality PPM Rx. You have to be very careful with such band-aides or you will get what you asked for, but not what you wanted.

Easy solution but that would be my last option, before I want to have a CLEAN plane in PPM, if I donīt solve this, I would think to replace components, BTW, I think this components placement is perfect, the only bad thing is the long servo wires. Right now range is acceptable, and the ground test I did at the flying field was good, I had control over plane more than what manufactures advice (more than 80 steps), but itīs very annoying to have the pan servo glitching.
One last thought, why do you think glitches are gone when I touch the antenna? because human body absorbs rf noise?

Here are the different ferrite cores Iīm using + an inside pic of my installation. Youīll notice that Iīm using also a plastic
tubular ferrite, this one I bought from LHS. On these pics I donīt have all ferrites installed, but when I tried I had.

Attached Thumbnails

  • telemaster_005.jpg
  • telemaster_006.jpg

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#42 Wavess

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Posted 28 March 2008 - 11:48 AM

More pics

Attached Thumbnails

  • telemaster_007.jpg
  • telemaster_008.jpg

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#43 Mr.RC-Cam

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Posted 28 March 2008 - 12:32 PM

Do u think some cap would be needed too?

I don't believe so. If the problem was due to a peak current derived voltage brownout at the receiver, then a big cap there would help. But I don't think that is the case here. But, if you have a servo that is missing the little ceramic caps on its brushed motor, then that would explain some of the problem.

Iīve noticed that the glicher servo is the digital pan (hyperion) but this could be understandable because it has 2 times the travel the other servos have.

Grab the programmer and return it to normal travel. That will be more useful for your observations.

One last thought, why do you think glitches are gone when I touch the antenna? because human body absorbs rf noise?

Normally this sort of action would merely detune the antenna and make it less efficient (less sensitive). That is what I suspect is happening in your case, but it is hard to say.

Here are the different ferrite cores Iīm using + an inside pic of my installation. Youīll notice that Iīm using also a plastic tubular ferrite, this one I bought from LHS.

I don't see many wraps on the tubulars, as well as the donut toroid in the fuselage photo. Picture #2 was what I would use as a minimum wrap count for the donut types. You can get by with less wraps on a long tubular, but I'm mostly a donut user so that is where my main experience is.

With these things, more wraps means more common mode noise reduction. I usually do not see a significant impact until at least a half-dozen tight wraps are used. I've had instances were it took a lot more to do anything at all. Plus, the snap together split core types, as seen in photo 3, are about half as effective as one of similar size that is one piece. Lastly, the ferrite cores come in a variety of recipes; I tend to use type 43 and 77 for these applications. Of course the use of toroids, on their own, may not offer a remedy, but they won't hurt things at all.

Keep in mind that these sort of problems often do not have a single source that causes the problem. Sometimes its several related issues that, when taken together, cause a lot of headaches.
- Thomas

#44 Wavess

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Posted 04 April 2008 - 08:22 AM

After many and many testings on this issue, Iīve reached some conclutions on this problem:

Seemed that the 2 tail servos were causing some kind of interference due to their long cable and due to their almost parallel tracing with the 35mhz rx antenna wire. Well installed 2 toroids on both channels and now the situation donīt get worse when I connect them. But here a mistery, last day, I removed toroids, plug servos directly to rx, and seemed that everything were ok, so appeared that problem had gone without toroids, anyway since I had 1 issue the other day, now I remain using those toroids.

Found that my OSD, while I now have connected to my rx, (I didnīt have on previous Easystarīs config) there is some problems too, put 2 toroids, 1 on the power supply and the other one on the rx conection close to the rx, now seems that the problem has gone too, but depends on the day I test, sometimes I remain with some little difference between osd, on and off, and some days, there isnīt a difference, very weird.

With all the servos unplugged from the rx, there is a remaining glitch on pan servo, very little but there itīs. I installed other toroid on receiverīs end, and added 3 inductors close to the servo, tried with different values, 68uH, 47 uH, 33uH, 10uH, 5.6uH and 4.7uH, resulting the best the 3 4.7uH installed on each wire. Wanted to try with 6.8uH but didnīt have on stock, I think this would the best value for its resonant frecuency (37mhz)http://www.ariston.e...le.aspx?id=1768

Finally removed tilt twisted wire and installed a regular 3 servo wire with a toroid at the end.

Today I went to my flying field to try all these mods (previously tested on my backyard), the first problem I had was that my OSD have suddenly died, so I reconnected video signal trying to bypass my osd, then I had clear video to test.
I made 2 conventional flights with video on, all went much better than the other day, and I almost have same range than with my previous setup on the easystar, so I think now the installation is acceptable. Since this plane was intended to run with Aerolink 868, I think that the remaining issues are going to dissapear with this frecuency. But if I was going to use 35mhz on this plane forever, the result doesnīt convince me at all, Iīm supposed to get more range than with easystar, the components placement is by far better, so results have to be better too. I think that solution goes with different rx, or pan servo, this digital servo is sweet because donīt have to deal with more artifacts to get 180š pan, but for me it has caused lots of headaches.
The video problem have gone away alone, I have done nothing to solve it, I just lowered tiny mic gain, but the other day there were lines even with motor off
Tinymic on its location continues to get over saturated with wind, even with the gain to the minimum. Mr.RC-Cam, you have you mic on the same location than mine, donīt you have this problem too? I would place some foam on it.

All my toroids have 7 tight wraps, btw tubular ones do nothing, and itīs hard to get more than 3 of 4 turns.

So soon Iīll maiden this bird on fpv on 35mhz first and after on 868mhz.
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#45 Mr.RC-Cam

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Posted 04 April 2008 - 08:47 AM

Mr.RC-Cam, you have you mic on the same location than mine, donīt you have this problem too? I would place some foam on it.

Here is a test to try: With the mic gain at minimum, speak normally into the mic from a few inches away. The level should be very hard to hear (mostly silent). However, if minimum volume settings still strongly picks up your voice, then I suspect your A/V Tx already has a high-gain mic preamp in it (and Tiny-Mic is not needed in those situations). Otherwise, a piece of foam to act as a wind screen should be used.

All my toroids have 7 tight wraps, btw tubular ones do nothing, and itīs hard to get more than 3 of 4 turns.

I've never been impressed with the tubular variety.

BTW, I'm glad to hear that the glitch issue is essentially resolved for now. :)
- Thomas

#46 Wavess

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Posted 04 April 2008 - 11:32 AM

BTW, I'm glad to hear that the glitch issue is essentially resolved for now. :)


Yes not without your help, canīt wait to maiden in FPV
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#47 W3FJW-Ron

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Posted 04 April 2008 - 03:35 PM

I don't want to get this thread off track but need to ask a ?. Where do you guys get your toroids and what type/size are they? Powdered iron, ferrite, mix, etc.?

Edited by W3FJW-Ron, 04 April 2008 - 03:36 PM.

73
Ron

#48 Mr.RC-Cam

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Posted 04 April 2008 - 08:04 PM

Wanted to try with 6.8uH but didn't have on stock, I think this would the best value for its resonant frequency (37mhz)http://www.ariston.e...le.aspx?id=1768

The SRF value is the frequency where the choke has no reactance and essentially becomes a resistor. I don't think you want the SRF to match the R/C Freq. :)

Where do you guys get your Toroids and what type/size are they? Powdered iron, ferrite, mix, etc.?

The best choices can be found at any *real* electronic store (avoid the R/C hobby shop and faux electronic suppliers like Radio Shack). Look for Ferrite type 43 and 77, single piece donut shape. Get several appropriate sizes for experimentation. Basically, something that would allow at least six (more is better) tight cable wraps, yet still be compact. They are very brittle, so after cable wrapping place heatshrink on them for impact protection.
- Thomas

#49 W3FJW-Ron

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Posted 04 April 2008 - 09:17 PM

Thank you. I'll be visiting Digikey tomorrow.. I should ask are these 72 MC values, or 2.4 gc ?

Edited by W3FJW-Ron, 04 April 2008 - 09:20 PM.

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#50 Mr.RC-Cam

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Posted 04 April 2008 - 10:11 PM

The toroids are effective with VHF frequencies.
- Thomas

#51 W3FJW-Ron

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Posted 04 April 2008 - 10:22 PM

Thank you..

Ron
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#52 D4RK1

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Posted 05 April 2008 - 01:49 AM

Hi Wavess, nice plane you got there.. i am thinking about doing the same, once i learn how to fly properly :P

Since i am also situated in Europe i would like to know if you purchased the TME at hobby lobby and if the answer is yes, what did you pay for the shipment?
I am also very interested in the hardware you used in it. The links to hobbycity seem to have expired. I would like to know the model names of the equipment you used since i am kind of irritated by all the things involved in choosing the right brushless motor :P.

Thx, Jens

#53 Wavess

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Posted 05 April 2008 - 04:25 AM

Hi, I bought Telemaster from hobbylobby, I bought it during a summer trip to the USA. I think they were asking for 120$ shipping costs, but shipping with USPS cost me 60$. When I was on USA I shipped myself by USPS and that was about 60$, if I remember well.

I donīt know what you mean about broken links, I can see the items well, anyway, here we go again:

Motor: (TR 42-50A 700KV BRUSHLESS OUTRUNNER)

http://www.hobbycity...?idProduct=2099

ESC: TURNIGY Plush 60amp Speed Controller

http://www.hobbycity...?idProduct=2166

The battery is not shown anymore, but whatever 4S with at least 4100 mah should do well, try to go with 15C, we donīt need here a higher discharge lipo, and you can save some grams.

With this config and an APC prop 13x8E, system is pulling 47A, that means 714Watts :o plenty of power

The UBEC Iīm ussing is a castle creations ubec, I havenīt seen any noise coming from them. I think Iīm buying more of them, to use them for video as well.

http://www.castlecre...cts/cc_bec.html

I strongly suggest that you learn how to fly with an easier plane such as an easystar. Telemaster is not that hard, but for me itīs not a single trainer, itīs a bit more advanced

BTW, today I was testing one more thing, I placed an analog servo with 180š capable (external circuit) and place it on the same channel than my Hyperion digital servo, well the behavior was exactly the same for both, so I think I donīt have a problem on this. Since I received yesterday more hyperion digital servos, Iīll try with them to see what happens.
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#54 D4RK1

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Posted 05 April 2008 - 05:08 AM

Thx for the info, ive got several 3s Lipos, might it be possible to use them with the TME?

i already got an easystar and i am quite able in flying in it so far.. but still not enough to dare flying a wooden plane yet =) The last few "incidents" seemed to be more or less caused by mechanical/electric problems than human error.. thats an improvement i guess ^^

First i hab problems with Tamiya standard plugs i used to connect the Lipo with ESC.. they got hot and lost connection somehow which caused the ESC to loose power and after that the only way my ES went was down :P I am using 4mm Gold plugs now.

After that one of my wings dissassemled itself during flight, since i made the error to use Polyacrylate glue for the wing assembly. Used a proper glue this time.

Last but not least (but no severe crash happened here) the ESC i was using developed some sort of loose contact which caused it to shut down only seconds after i threw it. Bought a new one, no problems since...

so in retrospect you might call it a mixture of mechanical problems AND human error ^^ but i guess i am learning my lessons and hope to be able to take the next step in my "evolution" soon.

#55 Wavess

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Posted 06 April 2008 - 12:20 AM

Thx for the info, ive got several 3s Lipos, might it be possible to use them with the TME?


I donīt think so if you use the motor Iīve posted, there are other propulsion possibilities, do a search at rcgroups.com
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#56 Wavess

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Posted 24 April 2008 - 12:37 PM

After many days with bad weather here in Madrid and other technical problems today Iīve maidenned this telemaster on fpv. Itīs quite easy to fly with it, a little bit harder to land because there is no plane part reference and telemaster glides a lot, all have been great and was a succesful flight, now I would travel with it to the french meeting. Will post some videos after this event.
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#57 Mr.RC-Cam

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Posted 24 April 2008 - 12:53 PM

a little bit harder to land because there is no plane part reference and telemaster glides a lot

The TME does indeed glide a lot (very high lift wing). Without flaps, I find I have a hard time convincing it to land. :)
- Thomas

#58 philthyy

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Posted 28 April 2008 - 08:35 AM

See, now, its threads like this that make me think the Electro Telemaster should be my next FPV plane. I'm currently using a highly modified Slow Stick and an Easystar. Both are very nice for FPV, but I plan on adding all kinds of electronic goodies to my next FPV platform, which adds weight. Seems like the Electro Telemaster should be easily up to the task of carrying additional weight. I'm planning on having an OSD, multiple cameras, and a return to home device. Oh, and maybe a super high capacity battery. Something like 7-8000 mah. Would like at least a safe 45 minutes of flight time. You guys think this is possible with an Electro Telemaster?

#59 Wavess

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Posted 30 April 2008 - 11:40 AM

Telemaster is ideal to carry extra weight; right now I've ordered a second 3.300 4s lipo so I'd fly with a total of 6.600 mah, I think that would be enough to fly 45 minutes, we'll see. This plane will fly well with extra weight; but take care always heavier planes means more nervous too.
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#60 philthyy

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Posted 01 May 2008 - 09:34 AM

Yeah, extra weight is always enough to make me nervous. At least from what I've read, the Telemaster is a really gently flier, so that should help keep me somewhat calm. :) Does anybody have a suggestion for a GPS autopilot that is somewhat plug and play? I'm pretty sure I could work my way through any reasonable difficulties getting one to work with a Telemaster, but if it requires all kinds of custom programming, I doubt I'll be able to get it to work.