Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[xviper]

We have regular 3 phase overhead power lines (likely 11,000v) on one boundary of our field. Note that they do not pose a problem when flying the regular pattern.

However, boys will be boys so of course there have been those that attempt to thread the needle underneath them. Legend has it that everyone who has tried has suffered a momentary signal interruption.

The line I was talking about ran 138KV (138,000 volts). That was stepped down from 1/2 million volts about 5 miles upstream, where it was split off into smaller lines like the one running past our flying field.

PS. The power lines in the video I referred to were running through some very hilly terrain and may be part of a long power run. The longer the run, the higher the voltage to reduce line loss. Those kinds of power runs can have nearly 1 million volts running through them. The EM fields coming from those can be quite substantial. The towers in that video appear to be much, much bigger (and with 3 levels of wires) than those running near our old flying field.

[fredmdbud]

The line I was talking about ran 138KV (138,000 volts). That was stepped down from 1/2 million volts about 5 miles upstream, where it was split off into smaller lines like the one running past our flying field.

PS. The power lines in the video I referred to were running through some very hilly terrain and may be part of a long power run. The longer the run, the higher the voltage to reduce line loss. Those kinds of power runs can have nearly 1 million volts running through them. The EM fields coming from those can be quite substantial. The towers in that video appear to be much, much bigger (and with 3 levels of wires) than those running near our old flying field.

Any emissions from the powerlines are low-frequency (50 or 60 Hz) - digital spread-spectrum transmitters in the US & Canada are in the 2.4-GHz band, way out-of-band for interference noise.

The voltages are in the hundreds of kilo-Volts, not mega-Volts - both AC and high-voltage DC (HVDC) - perhaps you are thinking of Mega-Watts (power), not voltage.

Transmission lines and antenna (which are designed to transmit EM waves) are very different - it is undesirable for transmission lines to radiate that much power, because it would mean reduced power at the substations. Also, higher frequencies can be overlaid/superimposed on power line transmissions (power line communications), but these are regulated as any radio transmitter, i.e. must not cause interference - low power, low emission gain (which is a low bar since, again, transmission lines are not designed to radiate power to the outside).

If you know any geeks with spectrum analyzers and portable antenna, you could ask them to take readings at the suspected trouble spots.

[xviper]

Any emissions from the powerlines are low-frequency (50 or 60 Hz) - digital spread-spectrum transmitters in the US & Canada are in the 2.4-GHz band, way out-of-band for interference noise.

The voltages are in the hundreds of kilo-Volts, not mega-Volts - both AC and high-voltage DC (HVDC) - perhaps you are thinking of Mega-Watts (power), not voltage.

Transmission lines and antenna (which are designed to transmit EM waves) are very different - it is undesirable for transmission lines to radiate that much power, because it would mean reduced power at the substations. Also, higher frequencies can be overlaid/superimposed on power line transmissions (power line communications), but these are regulated as any radio transmitter, i.e. must not cause interference - low power, low emission gain (which is a low bar since, again, transmission lines are not designed to radiate power to the outside).

If you know any geeks with spectrum analyzers and portable antenna, you could ask them to take readings at the suspected trouble spots.

NO, I wasn’t thinking about “watts”. I was talking about kilo-volts. IE, thousand volts. My point ................. When power lines were up and running - dead zone. When power lines were removed - no dead zone, no loss of signal and no crashes in that area. Since those power lines have been gone for some time, there’s nothing to take readings for, even if I did now such “geeks”. I’m not going to agree with anything you’ve said since I don’t think you know anymore about this than I do.

[Gringotuerto]

Since those power lines have been gone for some time...

I had some response to this discussion, but posted it over at "Radios and Receivers" forum for any interested geeks:

https://www.hobbysquawk.com/forum/electronics-and-rc-accessories/rc-radios-receivers-and-accessories/304360-beams-of-death-in-the-air

[nuts-n-volts]

Amazing work, Jetman! Anyone would be exceptionally proud to own it. My hat's off to ya!

[kallend]

Any emissions from the powerlines are low-frequency (50 or 60 Hz) - digital spread-spectrum transmitters in the US & Canada are in the 2.4-GHz band, way out-of-band for interference noise.

The voltages are in the hundreds of kilo-Volts, not mega-Volts - both AC and high-voltage DC (HVDC) - perhaps you are thinking of Mega-Watts (power), not voltage.

Transmission lines and antenna (which are designed to transmit EM waves) are very different - it is undesirable for transmission lines to radiate that much power, because it would mean reduced power at the substations. Also, higher frequencies can be overlaid/superimposed on power line transmissions (power line communications), but these are regulated as any radio transmitter, i.e. must not cause interference - low power, low emission gain (which is a low bar since, again, transmission lines are not designed to radiate power to the outside).

If you know any geeks with spectrum analyzers and portable antenna, you could ask them to take readings at the suspected trouble spots.

Whenever I drive alongside high voltage transmission lines on I-80 just west of Morris, IL, coming from the Braidwood nuclear station, my VHF car radio temporarily goes silent or the AM radio generates a tremendous 120Hz buzz.

The radiated e/m from those lines is enough to swamp the circuitry in any receiver. It does not have to be in-band of the receiver for it to do so.

When I was a kid we lived close by the main BBC TV transmitter for London (Crystal Palace). I could connect a high impedance headset to my bedspring and listen to the TV sound. No tuning or amplification needed.

[Chrys]

Finally done with the cockpit...

Salut FRANK , beau travail mon ami . supers les détails comme toujours . Amitiés "CHRYS"

[janmb]

A turbine will not flame out due to signal loss unless the failsafe has been incorreclty set.

That is a matter of definition. A lot of pilots, as well as the regulations in a lot of countries dictate that an engine cut (not just idle) is required in a failsafe scenario.

It is however a good idea to do so with a tiny delay, so you can have a fair few lost frames without instantly cutting the engine. 0.5-1.0 second delay is plenty to avoid any false failsafe cases, while still cutting the engine quickly enough to ensure minimized crash energy.

[Raydar]

I am glad I am not the only one that sets my turbines to cut on failsafe, a must do over here and quite happy not to take the ignition source to the crash scene if I can help it. The frsky gear I use wont failsafe until 100 frames are missed or 0.9s and if using a redundant receiver like I do a further 0.9 seconds will pass before it decides there is no valid signal from that source either. The turbine itself will quit if it does not see a valid pwm signal after a couple seconds.

[t33jetman]

Skip

[The43rdHammer]

...That is a matter of definition. A lot of pilots, as well as the regulations in a lot of countries ...

You make a very astute point about local regulations which must of course be adhered to in full. If they are lacking however, common sense must prevail.

I'm very proud of our BMFA here in the UK, it has a proud tradition of defending the rights of model aviators. I expect the AMA is similar.

This is what it has to say about failsafes:


The emphasis is on regaining control of the model once the signal has been reestablished. That might be difficult to do if your turbine has shut itself down irrespective of the ability restart itself over time.

Anyway, I'm conscious of not hijacking this Mig-29 thread further...

[Evan D]

I like the use of “should” and “must”. You don’t have to have it but if you do it has to bring the engine to idle.

[Airguardian]

I like the BMFA philosophy on this issue.
It would be cool to be able to set time-delayed failsafes with two positions, as in, initial failsafe to idle, then totally cut power if Rx link doesn't come back in x-amount-of-time.
Does any known receiver do that?

Back to MiG topic, I had an accident yesterday. Came in too low for a low pass and hit a treetop.

The MiG won though! Gotta love the extra inertia of a 6kg airframe!
Came out in a heavy sideslip but I managed to straighten and level her out between tumbles with three or four meters to spare.

No video of this one ssadly... it would have been pretty epic.
Damage consists in a torn landing gear door along with part of the right wing leading edge root, missing plastic piece from the fuse that fixed the wing's LE and some scratches on the LERX on both sides.

After that I brought flaps down, deployed landing gear and performed the smoothest landing I've done in ages...

Worst part was my broken pride taking yet another dent!

[4qr1hu9n7]

I replaced all servos that are a standard installation by Freewing and found the following. The servo lead was severely pinched entering the servo case and after opening up the servo I found the soldering of the leads were very poor soldered to the terminals. Not to say that this is a universal problem, but I suggest that all servos be removed and inspected before using them.

[Elbee]

Salut FRANK , beau travail mon ami . supers les détails comme toujours . Amitiés "CHRYS"

Radar-Guy, Great work on the MiG 29 3DP Cockpit Design. Chrys, beautiful work on the build. Bravo Zulu, Sirs. Best, LB

[Teslamandex]

I replaced all servos that are a standard installation by Freewing and found the following. The servo lead was severely pinched entering the servo case and after opening up the servo I found the soldering of the leads were very poor soldered to the terminals. Not to say that this is a universal problem, but I suggest that all servos be removed and inspected before using them.

What surface was that servo assigned to?

[Evan D]

Main or nose? The Grand Cruiser uses the same ones, I have three nib. Where do you live I can offer web sites...

[Evan D]

After flying the MiG with TVs for the last couple weeks I took out my old trusty F-22 with TVs and on 8S. I put the MIG up for sale...

[GliderGuy]

Back to MiG topic and best landing...

Sooo lucky! Glad you got it down in one piece!

When I smacked the lamp post with my AL37 #2, my first thought was, “No rewind button for this!” as I watched foam rain down on the parking lot.

-GG

[Evan D]

I learned a long time ago to not fly in parking lots, to not fly near light poles, to not fly near trees, water towers, etc etc... It still amazes me how many fly in parks, parking lots or streets actively used by cars and pedestrians and think they are safe. And public beaches.