Kinda confused on your test case. When you say you are hovering how high off the ground are you hovering when you go negative pitch? They recommend 15ft as the lower limit FYI. Beyond that I think you are kinda on your own. I don’t use the GPS as my first rescue. I first try to save it myself. If that fails I reach for the rescue switch. If all that fails hopefully the gps saves it.

When your doing your speed runs you have a longer distance for the thing to calculate the trajectory.

If you read my post properly I have my Altitude Limit set at 10 meters why would I be flying lower than that to test it . I do not use this feature I’m just testing it all to see how it works .

Are you referring to Normal Rescue when you say you find rescue fairly reliable or are you referring to the Altitude Limit being reliable?
Second question is what is your flying style? Big air and sport with mild 3D and what maneuvers are you executing when you say it saves your model?

Regards,
Kevin

_________________
Blade 230 S / 230 S NF / 450X / 500X / 550X ~ Trex 470LM ~ OXY 3-285 / OXY 4-325 / OXY 4 MAX ~ Spektrum DX9 BE / DX6 Gen 2 ~ Spirit FBL
_______________________________________________
Team OXY Helicopter - Lynx Heli Innovations Field Rep

When I say reliable I am talking about the geolink. The exact spot it rescues is not consistent and should not be expected to be. If you are expecting it to rescue at the same exact height every single time I think you have the wrong expectation. Its going to be limited by the accuracy of the devices used to detect the current height. Same as return to home will not land "exactly" where you took off from. It accurate +/- 15 ft. The same should be expected in the z direction.

I fly 3D and some big air. Tick tock, rainbows,piro rainbow, hurricanes ect. Still working on piro flips but throw ugly piro flips in there as well.

I'm not discounting your experiments. Just trying to picture in my head what you are doing from your description. I wonder if your quick dissent is affecting the altimeter? If your upright and going inverted you are creating a vacuum under the blades. If your inverted going down you are creating positive pressure.

I'm sorry but I think you misunderstood my post as I was not referring to the accuracy as you mentioned above, but the overall execution of the Altitude Limit. I understand that it may stop close to a lower limit of 10 meters when set to 10 meters and may catch the model say for example at 8.5 or 9 meters because the velocity of descent was faster, but still was caught. However with the above example whether or not it catches and saves the heli is what the topic was and is all about. If I set it at the lower limit of 10 meters and I'm coming down fast ( 6° of negative pitch heli upright) and it catches the heli at 7 meters and bounces it backup I would be very happy with that, as it still saved my heli, but if it doesn't catch and bounce it up at all then that's when I would feel the feature failed to meet my expectations, and that's just my thoughts and may or may not be shared by others.

Same goes with the RTH feature if it comes back and hovers within 5 meters of where it was set to return to I'm more than happy with that, but if it didn't execute that feature and I set it up as per the manual I would be a little disappointed.

So again its not a matter of accuracy but a matter of the feature actually executing its intended purpose is what the topic was all about, and there are those who feel it is meeting their expectations and those who clearly posted it wasn't. I think it makes sense in morrchew's previous posting that maybe Altitude Limit is more geared towards scale pilots, novice pilots who are going to be careful hovering and doing slow maneuvers and not for pilots trying new hard 3D maneuvers hoping to be saved, because it seems it was not intended for faster vertical descending model situations.

Regards,
Kevin

_________________
Blade 230 S / 230 S NF / 450X / 500X / 550X ~ Trex 470LM ~ OXY 3-285 / OXY 4-325 / OXY 4 MAX ~ Spektrum DX9 BE / DX6 Gen 2 ~ Spirit FBL
_______________________________________________
Team OXY Helicopter - Lynx Heli Innovations Field Rep

That's the part I was commenting on. I'm not trying to be one of those guys that just says I have no problem so you must be crazy. I do not have the problem you are seeing so I am trying to understand what is different between what you are doing and what I am doing.

How long do you sit on the deck after the light on the GPS turns blue. I suspect and it would be nice if someone from Spirit could confirm that alititude is not just based on the Alitimeter but also the GPS.

If you have ever plugged your Spirit into a PC while its powered up and looked at the recorded height you will see some wild numbers and then as more sats come online the height becomes more accurate. Try it sit there and wait for the blue light on the GPS module to come on while watching the screen. It will get more accurate well past the point the blue light comes on. I suspect and its only a guess that if you program the start location while it's still acquiring then you get a less accurate start location and a less accurate altitude limit. What I have done is let it sit there for a good 20-30 seconds after that blue light turns on before setting the start position. I have found that to provide a more consistent altitude limit.

Maybe its a placebo affect because I dont know the firmware that is running. But that has what has worked for me. If I dont want to wait I just set the hard deck higher.

is possible that you used glue or tape to secure the connector ?
there is a warning on manual about that

http://manual.spirit-system.com/index.p ... k_Mounting

>> Do not cover GeoLink connector with any tape, glue or paint.
>> Opening above the connector is used to determine ambient pressure and altitude.

As a rule I like to wait at least 30 seconds after the GeoLink indicator light goes solid blue, before spooling up the model. I have done several bench tests with a PC connected to the Spirit Pro while in the GeoLink info tab and found it can take up to as much as a few minutes to lock onto at least 8 satellites and this is indoors. I usually get a max of 12 satellites almost every time, and each time I re-initialize the software the acquisition time is reduced significantly.
I think the next time I test the Altitude Limit I will give it at least 5 more minutes after the indicator light goes solid blue to acquire as many satellites as possible before spooling up on the very first flight to see if that makes a difference in how it performs. I would think that each flight after in the same session would require less time for proper satellite acquisition as the unit will be familiarized with that location. Hopefully this might yield better test results, one will have to wait and see.

Best Regards,
Kevin

_________________
Blade 230 S / 230 S NF / 450X / 500X / 550X ~ Trex 470LM ~ OXY 3-285 / OXY 4-325 / OXY 4 MAX ~ Spektrum DX9 BE / DX6 Gen 2 ~ Spirit FBL
_______________________________________________
Team OXY Helicopter - Lynx Heli Innovations Field Rep

Both pressure sensor and GNSS are used for determining altitude of the model.
Spirit Settings software is displaying only readings from the pressure sensor. In the most cases pilots are doing setup in a building which is nearly useless for a positioning systems.

Anyway for real flights it is important that there are 12 satellites always which should be the case usually within 40 seconds from battery power up.
Waiting minute or so should be enough (from power up time) if the model has clear sky visibility.

Waiting has really benefit for Altitude Limit feature if it is first flight of the day or in a few hours. With next powerups GeoLink should be fixed within ~6 - 10 seconds.

Testing the altitude limit so that you will change collective pitch quickly is unfortunately the worst way as blades are changing pressure very significantly. Testing in a real flight with a high lower limit should be the best and the safest way.

_________________
Spirit System developer

Hello urgno,

No, I have not placed any tape or other adhesives on the GeoLink unit, the cable plugs in snug and securely so there is no need for additional securing material. The GeoLink is mounted on metallic free mounting hardware and is mounted at 50 cm from the tail servo and further from any other electronic components thus reducing the chance of any electrically induced interference. I have taken every precaution I know of to provide for that the unit works at peak proficiency.

Best Regards,
Kevin

_________________
Blade 230 S / 230 S NF / 450X / 500X / 550X ~ Trex 470LM ~ OXY 3-285 / OXY 4-325 / OXY 4 MAX ~ Spektrum DX9 BE / DX6 Gen 2 ~ Spirit FBL
_______________________________________________
Team OXY Helicopter - Lynx Heli Innovations Field Rep