Fool unmasked?

[Meta4]

Also keep in mind that if you take off from a table or any other elevated position, your altimeter/barometer will not accurately measure ground distance as it resets whenever you takeoff. I’m not sure, but could this affect landings if the bottom sensors are not working correctly since your drone will think it’s lower than it actually is?

Think about it- If your bottom sensors are not working and your drone is auto lending, the barometer/altimeter will tell the drone that it’s at ground level at the elevated takeoff height, and the motors will shut off too soon making your drone fall the remainder of the distance. It’s sort of like what happened to the Mars Polar Lander.

DJI's design engineers had enough imagination to think that drones might not always land at the same place they were launched.
And besides ... The recorded home point contains no altitude information, just latitude and longitude.
Land anywhere you like, at any altitude relative to the launch spot and it makes no difference.

 

[Floater]

Moving in a slightly different direction...... would an aluminum landing pad negate the effects of iron underneath it?

In a word, no. Aluminum is nonmagnetic, but is a conductor. Static, non-moving magnetic fields will be unaffected. Moving magnetic fields will be "retarded" or dampened due to eddie currents that are generated that oppose the applied field. As soon as the motion stops, the edie current dies away and the aluminum again becomes transparent to the appied field. Maxwell and Tesla had a thing or two to say about this effect.

 

[AMann]

In a word, no. Aluminum is nonmagnetic, but is a conductor. Static, non-moving magnetic fields will be unaffected. Moving magnetic fields will be "retarded" or dampened due to eddie currents that are generated that oppose the applied field. As soon as the motion stops, the edie current dies away and the aluminum again becomes transparent to the appied field. Maxwell and Tesla had a thing or two to say about this effect.

That too, is why metal detectors will work with aluminum.

 

[John235]

Alright, I'm putting myself out here like an idiot, but relying on the charity of the "constructive criticism" I've seen in these forums I must ask these questions. I've only flown for two months and have 82 successful flights logged. 90% of those flights originated and terminated from my mobile launch/recovery platform (MLRP)(okay, I made up that acronym). Having seen repeated forum comments about metallic interference e.g. rebar in sidewalks, wristwatches, etc. I need to know:

1. Have I been very lucky and am flirting with disaster?
2. Does the Chevy Silverado possess more plastic than metal?

I only get the "interference/recalibrate" warning when I have traveled 20 miles or so from my last flight location. After recalibration, my flight direction arrow matches my true heading and the home point sets correctly. I use auto take-off and RTH is accurate to less than 2 meters (I always take over control when the AC is overhead).

I hate to give up this MLRP as it gets 16-22 mpg, delivers 355 hp @ 5600 rpm, has a 2068 lb. payload, and is 4WD. But, I don't want to trash my M2P either...

View attachment 74523View attachment 74524View attachment 74525

I agree with cyborg. I use an old truck floor mat for a landing pad anyway, so I would take one from my truck and take off 20 feet from the truck. But if it works for you and you are practiced at takeoff and landing this way, fine, but I would worry myself at landing on any raised platform, where a missed approach could case my MP to clip the side of the platform. But that's me.

 

[Rick W]

Chevy Silverado has a predominantly aluminum polimer body. Similar to most aircraft, steel is too heavy to use for good fuel economy. Stay away from the engine compartment and you will avoid most of the steel and electromagnetic interference. Ever try to put a refrigerator magnet on the outside of a stainless steel refrigerator door? I think that if you took that same refrigerator magnet and tried to put it on the Silverado, you would not be successful. Enjoy your MLRP.

 

[joeruby]

Alright, I'm putting myself out here like an idiot, but relying on the charity of the "constructive criticism" I've seen in these forums I must ask these questions. I've only flown for two months and have 82 successful flights logged. 90% of those flights originated and terminated from my mobile launch/recovery platform (MLRP)(okay, I made up that acronym). Having seen repeated forum comments about metallic interference e.g. rebar in sidewalks, wristwatches, etc. I need to know:

1. Have I been very lucky and am flirting with disaster?
2. Does the Chevy Silverado possess more plastic than metal?

I only get the "interference/recalibrate" warning when I have traveled 20 miles or so from my last flight location. After recalibration, my flight direction arrow matches my true heading and the home point sets correctly. I use auto take-off and RTH is accurate to less than 2 meters (I always take over control when the AC is overhead).

I hate to give up this MLRP as it gets 16-22 mpg, delivers 355 hp @ 5600 rpm, has a 2068 lb. payload, and is 4WD. But, I don't want to trash my M2P either...

View attachment 74523View attachment 74524View attachment 74525

i recommend you study post #1 at this link on compass errors and how the AC can be confused:

Compass error demonstration

With compass errors arising from magnetic interference one of the major causes of problems, I thought it might be useful to show a controlled demonstration of how that works. To recap, when the aircraft is powered up the compass (3-axis magnetometer) reading is used to initialized the IMU yaw...

mavicpilots.com

I found his experiment very interesting.
Joe
KC7GHT

 

[Moose1967]

1. This takeoff pad position is (a) a good idea, (b) the last time this drone will ever fly (c) obviously the idea of a beginner and its good he didn’t really try it.

View attachment 74527

Love it lol

 

[BrucenYvette]

Compared with the large number of seasoned veterans who have answered, my reply lacks the same experience and expertise. But...I'll venture my comment anyway...from an experience that I HAVE had with my MP Pro.

While you may not be getting any error messages (compass error-related) at initial take-off, I have had the experience of NOT getting any errors on take-off, but have experienced screen show a compass error 1500 feet down range at 150' altitude and my MPP drop into ATTI mode. Happened to me TWICE flying out of a same location, and the second time nearly lost my drone to TBE (toilet-bowl effect). My best guess is that my MP thought its compass was OK at the point of take-off, but somewhere down-range compass and IMU got into a disagreement which they couldn't resolve...and while they're arguing, my MP was drifting away in lazy circles in the wind! I almost crashed it the second time because it went into TBE at 25% battery, and while I'm fighting to get the drone back to home, I got down under 10% battery which forces auto-land...and it was NOT a good place for a landing. Saved it by the skin of my teeth.

 

[PropSpin]

Also agree with @Thomas B - no warning, no problem. While RF sources and magnetic materials like iron can cause issues, that's only likely to be an issue if you are either right on top of a major source and/or calibrating your device before pushing the envelope.
Of the two things that can be interfered with, GPS and the link between RC and controller:

If the GPS signal is getting thrown off, once your airborne and away from the source of the interference it'll achieve a stable lock, so initial problems are not that serious. It may cause issues with the RTH location being slightly off, but that's basically where you are most likely going to be in order to recover the drone anyway, so you can intervene (cancel and manual landing) if required.

If the RC-AC link is being disrupted, the RC will inform your of this by beeping and displaying a message on the Go4 screen. If you get this pre-flight, fairly obviously you should find a different take off location, or try adjusting your position relative to the drone. If you're already airborne, it'll do so with plenty of margin before the signal is swamped by noise/interference, so again you can intervene if necessary by retracing your flight path or increasing the distance from any obvious sources of interference. Generally this is only going to be a problem if there is a significant distance between the RC and aircraft, or the antennae are not pointing in the right direction. There's also a corner case where you can actually have too strong a signal, but that's not really applicable here.

A GPS receiver will not be affected by being near a metal object unless it is enclosed or obstructed. At close range, the RF signal shouldn't be affected either, unless, again there is obstruction.

What can be affected is the compass, and if it is, things will not get better once airborne and away from the source of interference. The IMU and compass will disagree and the AC will go nuts trying to find the correct heading once the compass measurement abruptly changes after the AC moves away from the metal object and the IMU not sensing any corresponding yaw.

 

[PropSpin]

Alright, I'm putting myself out here like an idiot, but relying on the charity of the "constructive criticism" I've seen in these forums I must ask these questions. I've only flown for two months and have 82 successful flights logged. 90% of those flights originated and terminated from my mobile launch/recovery platform (MLRP)(okay, I made up that acronym). Having seen repeated forum comments about metallic interference e.g. rebar in sidewalks, wristwatches, etc. I need to know:

1. Have I been very lucky and am flirting with disaster?
2. Does the Chevy Silverado possess more plastic than metal?

I only get the "interference/recalibrate" warning when I have traveled 20 miles or so from my last flight location. After recalibration, my flight direction arrow matches my true heading and the home point sets correctly. I use auto take-off and RTH is accurate to less than 2 meters (I always take over control when the AC is overhead).

I hate to give up this MLRP as it gets 16-22 mpg, delivers 355 hp @ 5600 rpm, has a 2068 lb. payload, and is 4WD. But, I don't want to trash my M2P either...

View attachment 74523View attachment 74524View attachment 74525

Is the bed, and all components of the bed cover of this truck aluminum? Even if only the cover components closest to the drone are aluminum, that would explain why you've gotten away with this - your'e apparently far enough away from any ferromagnetic materials to effect the compass.

 

[zocalo]

A GPS receiver will not be affected by being near a metal object unless it is enclosed or obstructed. At close range, the RF signal shouldn't be affected either, unless, again there is obstruction.

All true, but I made it clear in the second sentence that I was talking in a more general sense about about RF interference as well as magnetic, not just proximity to metal. The former can, with the right combination of frequencies and amplitudes, absolutely mess with your GPS. Other than that though, as long as the drone has decent visibility of the sky and is not very near the North or South pole, the only issue you should have with GPS is how long it takes to get a fix on enough satellites.

 

[kydroneman]

Alright, I'm putting myself out here like an idiot, but relying on the charity of the "constructive criticism" I've seen in these forums I must ask these questions. I've only flown for two months and have 82 successful flights logged. 90% of those flights originated and terminated from my mobile launch/recovery platform (MLRP)(okay, I made up that acronym). Having seen repeated forum comments about metallic interference e.g. rebar in sidewalks, wristwatches, etc. I need to know:

1. Have I been very lucky and am flirting with disaster?
2. Does the Chevy Silverado possess more plastic than metal?

I had a Nissan Frontier and had a cover similar to yours, other than the occasional compass calibrate message, I never experienced any problems taking off from the cover or landing.

 

[Treeofliberty]

Late to the party, but I launch off the aluminum bed cover in my F-150 all the time (M2P) with no issues. I have also launched from the cloth cover on my F-350 with no issues. Proximity to the trucks doesn't appear to cause me any trouble. Now I want to get a second drone so I can have a little aircraft carrier.

 

[davidzimagery]

I've done this a few times. The only difference is that my Silverado is red. So far no problems.

 

[CentralVAphoto]

Although, sadly I only get 12 to 13 mpg out of the Tundra as a mobile launch platform.

'ShouldBeWorking' - you lucky xxxxxxx! My F-250 dreams of 12-13 mpg... Of course, it's towing while dreaming

I launch from my tonneau cover whenever the ground isn't a good option (sand, tall grass, goose poop, etc.) and never had a warning or problem. Ford Super Duty's are made from real steel and it's everywhere. I launch from the back near the tailgate and generally land in my flat palm (learned not to use my fingers, the hard way...) using left stick down, just like ground landings. My hand is big enough to make the downward sensors think it's a landing surface (and so it is...). I don't land on the truck anymore, after a near miss with the back window following an unexpected switch to Atti Mode. Probably due to compass error. For what it's worth, I've had my MP compass go out of whack on real estate shoots where the owner has reported past lightning strikes due to ferro-magnetic geologic formations, aka iron in the ground. It's unpredictable and unsettling, to say the least.

Chevy Silverado shouldn't be a problem for launch. They're made out of Canadian metal, which is mostly plastic... Towing the drone would be the real problem for a Silverado - some of our drones can weigh as much as four or five pounds. Dude - you knew you were gonna hear from us Ford Truck owners, right?

Cheers

 

[CentralVAphoto]

Now I want to get a second drone so I can have a little aircraft carrier.

I like where your head's at...

 

[PAW]

'ShouldBeWorking' - you lucky bastard! My F-250 dreams of 12-13 mpg... Of course, it's towing while dreaming

I launch from my tonneau cover whenever the ground isn't a good option (sand, tall grass, goose poop, etc.) and never had a warning or problem. Ford Super Duty's are made from real steel and it's everywhere. I launch from the back near the tailgate and generally land in my flat palm (learned not to use my fingers, the hard way...) using left stick down, just like ground landings. My hand is big enough to make the downward sensors think it's a landing surface (and so it is...). I don't land on the truck anymore, after a near miss with the back window following an unexpected switch to Atti Mode. Probably due to compass error. For what it's worth, I've had my MP compass go out of whack on real estate shoots where the owner has reported past lightning strikes due to ferro-magnetic geologic formations, aka iron in the ground. It's unpredictable and unsettling, to say the least.

Chevy Silverado shouldn't be a problem for launch. They're made out of Canadian metal, which is mostly plastic... Towing the drone would be the real problem for a Silverado - some of our drones can weigh as much as four or five pounds. Dude - you knew you were gonna hear from us Ford Truck owners, right?

Cheers

Of course...

 

[Donnie Frank]

Alright, I'm putting myself out here like an idiot, but relying on the charity of the "constructive criticism" I've seen in these forums I must ask these questions. I've only flown for two months and have 82 successful flights logged. 90% of those flights originated and terminated from my mobile launch/recovery platform (MLRP)(okay, I made up that acronym). Having seen repeated forum comments about metallic interference e.g. rebar in sidewalks, wristwatches, etc. I need to know:

1. Have I been very lucky and am flirting with disaster?
2. Does the Chevy Silverado possess more plastic than metal?

I only get the "interference/recalibrate" warning when I have traveled 20 miles or so from my last flight location. After recalibration, my flight direction arrow matches my true heading and the home point sets correctly. I use auto take-off and RTH is accurate to less than 2 meters (I always take over control when the AC is overhead).

I hate to give up this MLRP as it gets 16-22 mpg, delivers 355 hp @ 5600 rpm, has a 2068 lb. payload, and is 4WD. But, I don't want to trash my M2P either...

View attachment 74523View attachment 74524View attachment 74525

If metal is a problem, you'll get compass errors before you launch. That said, most UAV pilots avoid metal at all costs.

I have one client where I launch from an area surrounded by metal fencing in a roughly 12' x 12' area. So far, no problems, but you can bet I paid attention to the compass like a hawk the first couple flights. You can also bet that I land as close to dead center as possible.

D

 

[Donnie Frank]

Also keep in mind that if you take off from a table or any other elevated position, your altimeter/barometer will not accurately measure ground distance as it resets whenever you takeoff. I’m not sure, but could this affect landings if the bottom sensors are not working correctly since your drone will think it’s lower than it actually is?

You don't say?



D

 

[AMann]

You don't say?

View attachment 74921

D

Well, clearly it is working very well

There’s a place at the Salton Sea where I fly that my homepoint is about -220ft below sea level, and it does report accurate negative elevations from there.