Vct with Evo fbl
Posted by Shawn550
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Vct with Evo fbl May 15, 2023 03:46AM |
Registered: 7 years ago Posts: 37 |
Hi,
I spent some time at the field ground testing the signal on my nimbus 550 and wanted to share my experience.
So I have the fbl mounted on the rear of the model with the antennas forward wire rear. On this model this orientation makes it difficult to achieve a 90 degree mount setup using anything I have seen but it allows easier servo wire routing and plugging into the fbl. I have seen pilots, some pro, run the antennas down the frame. So I did similar but on an angle so they stuck out past the frames to the sides of the boom.
First test with the model on the ground I walked the perimeter of the flight runway. This space is approximately 125 yards or 385ft left to right and the model was in the middle. Front to back is approximately 40 yards or 115ft and the model was 10ft from the front.
Under these conditions I did two laps around the field. Both times I had packet loss and one of them the model shutdown and restarted. The packet loss entry happened exactly when the dbm changed from -84 to -85. The full reboot with several packet loss entries happened when it stayed at -85. Nothing happen at -84 it had to hit -85.
After this test I put the model up on a table and walked the perimeter. The signal was weak but I did not reach over -80dbm. When looking at the rx bars I did notice one would be low and the other high. When I got to the center of the model they would slightly even then as continued reverse. So I went back to the model and taped the antennas on top of the evo in a v setup 90 degree. This put them above the frames and then I walked the perimeter again. The dbm did not go over 70 I believe and the rx bars remained much more even as I walked with overall improvement of signal strength.
I performed this same process on my logo 700 with neo. I had walked very close to 75 yards to the right of the model and at least 100 yards to the woods with my back to the model to even get the dbm to hit -85. I really had to try and when I did there was no packet loss and I got it to stay there and there was no reset. So I question why the evo has packet loss instantly on -85 and the neo does not.
Anyway I did fly my nimbus with success. I did not take advantage of the higher servo settings. I adjusted gains as needed and performed some hovers piros and rpm changes 2000, 2200, 2400 and the log was vibrations free. Next time out I will do some 3d flight and if the logs look good start increasing cyclic hz.
I know it may be early to figure out what the problems these other users have experienced but if there is anything you can tell me I would like to know. I will be installing 3 more evos on my 700s this week.
Thank you.
I spent some time at the field ground testing the signal on my nimbus 550 and wanted to share my experience.
So I have the fbl mounted on the rear of the model with the antennas forward wire rear. On this model this orientation makes it difficult to achieve a 90 degree mount setup using anything I have seen but it allows easier servo wire routing and plugging into the fbl. I have seen pilots, some pro, run the antennas down the frame. So I did similar but on an angle so they stuck out past the frames to the sides of the boom.
First test with the model on the ground I walked the perimeter of the flight runway. This space is approximately 125 yards or 385ft left to right and the model was in the middle. Front to back is approximately 40 yards or 115ft and the model was 10ft from the front.
Under these conditions I did two laps around the field. Both times I had packet loss and one of them the model shutdown and restarted. The packet loss entry happened exactly when the dbm changed from -84 to -85. The full reboot with several packet loss entries happened when it stayed at -85. Nothing happen at -84 it had to hit -85.
After this test I put the model up on a table and walked the perimeter. The signal was weak but I did not reach over -80dbm. When looking at the rx bars I did notice one would be low and the other high. When I got to the center of the model they would slightly even then as continued reverse. So I went back to the model and taped the antennas on top of the evo in a v setup 90 degree. This put them above the frames and then I walked the perimeter again. The dbm did not go over 70 I believe and the rx bars remained much more even as I walked with overall improvement of signal strength.
I performed this same process on my logo 700 with neo. I had walked very close to 75 yards to the right of the model and at least 100 yards to the woods with my back to the model to even get the dbm to hit -85. I really had to try and when I did there was no packet loss and I got it to stay there and there was no reset. So I question why the evo has packet loss instantly on -85 and the neo does not.
Anyway I did fly my nimbus with success. I did not take advantage of the higher servo settings. I adjusted gains as needed and performed some hovers piros and rpm changes 2000, 2200, 2400 and the log was vibrations free. Next time out I will do some 3d flight and if the logs look good start increasing cyclic hz.
I know it may be early to figure out what the problems these other users have experienced but if there is anything you can tell me I would like to know. I will be installing 3 more evos on my 700s this week.
Thank you.
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May 15, 2023 09:43AM |
Registered: 17 years ago Posts: 17,792 |
Hi,
what you see is good, in my opinion. 125 yards or 114 m approx., with the model on the ground, is good.
90° angle is less important than distance between the antenna wires, and dampening/shielding, from conducting surfaces on the model, like carbon, aluminum etc.
You have almost no range any more, if you e.g. put the antenna wire directly onto a carbon side frame.
We have calibrated our range check in a way so you can walk around the model in a 10 m/yd radius.
The antenna gains you should see there _at least_ are marked by threshold lines.
If better, all is well.
It's normal that you see different antenna gains, depending on the orientation between transmitter and receiver (and vice versa, both are transceivers, both are transmitting and receiving). VLink monitors the radio link constantly, and always uses the best possible link.
It's indeed early to comment on the problems users have, because almost every setup and situation is different.
Of course there are similarities, and of course it becomes more clear.
Mainly, I personally think it's (again ...) all about the overall vibration level on the model.
And not about the visible or easily palpable vibration, from rotating parts, which are also reflected by the normal vibration analysis.
It's about high frequency vibration, with steep slopes, sided, e.g. from drive trains, every gear tooth causing one hard click, with kW power.
And from resonance caused from almost everywhere, e.g. rotor systems (main and tail) without noteworthy dampening.
When at it, I'd suggest you run Vibration Analysis Pro, write the graph, mind to take a screenshot to save it, then you can see the overall load and max. G-forces from all sensors. This can help telling if problems could arise, or if it's rather safe.
Do test runs on the ground, no blades, and when you take the model to the air the first time, be prepared to abort, to change to a lower rpm, to auto down. It's new sensor technology, so even on model which was flying well with e.g. VBar NEO, you might experience different results, with VBar EVO (or any other different FBL, the key word is 'different').
Kind regards
Eddi
Born to fly ...
forced to work.
what you see is good, in my opinion. 125 yards or 114 m approx., with the model on the ground, is good.
90° angle is less important than distance between the antenna wires, and dampening/shielding, from conducting surfaces on the model, like carbon, aluminum etc.
You have almost no range any more, if you e.g. put the antenna wire directly onto a carbon side frame.
We have calibrated our range check in a way so you can walk around the model in a 10 m/yd radius.
The antenna gains you should see there _at least_ are marked by threshold lines.
If better, all is well.
It's normal that you see different antenna gains, depending on the orientation between transmitter and receiver (and vice versa, both are transceivers, both are transmitting and receiving). VLink monitors the radio link constantly, and always uses the best possible link.
It's indeed early to comment on the problems users have, because almost every setup and situation is different.
Of course there are similarities, and of course it becomes more clear.
Mainly, I personally think it's (again ...) all about the overall vibration level on the model.
And not about the visible or easily palpable vibration, from rotating parts, which are also reflected by the normal vibration analysis.
It's about high frequency vibration, with steep slopes, sided, e.g. from drive trains, every gear tooth causing one hard click, with kW power.
And from resonance caused from almost everywhere, e.g. rotor systems (main and tail) without noteworthy dampening.
When at it, I'd suggest you run Vibration Analysis Pro, write the graph, mind to take a screenshot to save it, then you can see the overall load and max. G-forces from all sensors. This can help telling if problems could arise, or if it's rather safe.
Do test runs on the ground, no blades, and when you take the model to the air the first time, be prepared to abort, to change to a lower rpm, to auto down. It's new sensor technology, so even on model which was flying well with e.g. VBar NEO, you might experience different results, with VBar EVO (or any other different FBL, the key word is 'different').
Kind regards
Eddi
Born to fly ...
forced to work.
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May 15, 2023 12:19PM |
Admin Registered: 18 years ago Posts: 7,454 |
I did a small real world comparison at the edge of the range. No running heli though. I compared some NEOs with my EVOs. I could not find a relevant difference. NEO an EVO both loose connection at -85dB which is expected, since with the 16dB Gain of the Frontend we are at -101dB real level.
Sometimes it shows -86, sometimes its -84 when it disconnects. This depends quite a bit on other 2.4Ghz Noise that is around. I am in urban environment here.
A range of >100m with heli sitting on ground sounds normal, you can expect >1000m in the air then. Problems in this range usually are self induced by something on the heli.
If i try to compare them as close as possible, the EVO has the lead (by range, not numbers), but only marginally.
If you shade the antennas with your body, you can lose up to 20db, which is a hug e difference. Grass and Body contains lots of water, which perfectly absorbs 2.4Ghz. Thats why its used in Microwave ovens...
In general IMO ist very unlikely to loose connection because of lack of Range in a Heli.
so long ... Uli
http://www.vstabi.de
Sometimes it shows -86, sometimes its -84 when it disconnects. This depends quite a bit on other 2.4Ghz Noise that is around. I am in urban environment here.
A range of >100m with heli sitting on ground sounds normal, you can expect >1000m in the air then. Problems in this range usually are self induced by something on the heli.
If i try to compare them as close as possible, the EVO has the lead (by range, not numbers), but only marginally.
If you shade the antennas with your body, you can lose up to 20db, which is a hug e difference. Grass and Body contains lots of water, which perfectly absorbs 2.4Ghz. Thats why its used in Microwave ovens...
In general IMO ist very unlikely to loose connection because of lack of Range in a Heli.
so long ... Uli
http://www.vstabi.de
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