How to Troubleshoot your AR Drone after a crash (1.0 and 2.0)…….
Sooner or later (probably sooner) you are going to have a nice little wreck with your AR Drone. Maybe you hit a wall too hard, hit the ceiling, smacked a tree, or sucked in a twig. Wrecks, crashes, and other emergency stops are par for the course with the AR Drones.
In many situations, you just need to place the AR Drone back on a flat surface and start over. While this may work most of the time, other times the drone won't level properly, one motor might not spin up, or some other problem will come up. That's when you need to try some alternative solutions.
The tips below will have (1.0) for the original Parrot AR Drone or (2.0) for the current Parrot AR Drone 2.0. Tips that cover both the AR Drone 1.0 and AR Drone 2.0 will have (1.0 / 2.0).
1. Always do a Flat Trim / Calibrate.
(1.0) Before every flight, crash or not, always do a Flat Trim, then, once you launch, let the AR Drone hover for about 10 seconds before flying. If all is well at this point, you should be good to go.
(2.0) Before every flight, crash or not, always calibrate the AR Drone 2.0. After connecting the battery place the AR Drone 2.0 on as level of a surface you can find. On your flight app find and click “Calibrate” before taking off. Then take off and allow the AR Drone 2.0 to hover, once a nice hover has started click the “calibrate” button again and allow the AR Drone 2.0 to spin 360 degrees.
Doing the above allows the AR Drones gyros and sensors to reset and allow a good flight.
2. Reset after a crash.
(1.0) If you are using Parrot's FreeFlight app, then you will need to press the reset button on the bottom of the AR Drone. You will need an “in-field drone reset tool” (a toothpick for example). If you are using AR Drone Flight for Android, the Emergency button on the top will become a Reset button when the AR Drone is not flying. Pressing the RESET will recalibrate the sensors and will almost always get you back flying again.
(2.0) Normally it is not necessary to push the rest button after a crash, just calibrate the AR Drone 2.0 as told in tip 1 (2.0) above. But if the AR Drone 2.0 still has issues, the reset button can be found under the battery through a small hole in the battery tray. The button is a fair distance down inside, but with steady hands you will be able to push it with the “in-field drone reset tool”.
Note: We recommend a nonconductive tool (toothpick or small plastic rod) for the “in-field drone reset tool”. Accidentally shorting out the AR Drones circuit board by using something like a paper clip could cause damage that will require the circuit boards replacement
3. One or more motors won’t spin up.
(1.0 / 2.0) This is a fairly rare phenomenon but it can happen in a flight just after a crash. You have to be fast on this because without all the motors spinning on launch, the AR Drone will only make it about a foot or two into the air and do a nasty backflip (hopefully not into something). If pressing the reset button doesn't solve this one, first check the motor gears for any broken or grit / dirt binding them up. Also check that there doesn't seem to be any wobble in the prop shaft by unplugging the battery and spinning the propellers a few times by hand (see tip 5 if you have a bent shaft). Follow the instructions in tip 2 above and hopefully that should put you back into the air. After trying all this and the motor still does not turn, you might have blown the motor, ESC, or the motherboard.
4. All motors are spinning but the AR Drone flips over.
(1.0 / 2.0) See tips 1 and 2; also check the motor gears for any broken or grit / dirt binding them up. Then check that there doesn't seem to be any wobble in the prop shaft by unplugging the battery and spinning the propellers a few times by hand (see tip 5 if you have a bent shaft).
5. AR Drone takes off but seems to be unstable and somewhat noisier than before.
(1.0 / 2.0) You may notice the AR Drone wobbling a bit or it will drift and not hold a stable hover. After a number of crashes, the propeller drive shafts could be bent or the propellers are damaged / warped. These problems can be determined in a couple of ways. One is to just spin the props by hand and at eye level look to see if any wobble in the prop shaft is present. Inspect each propeller for cracks or other damage (if you find any cracks or chips in the propellers DO NOT FLY with them).
If you are 100% certain there is no damage to the propellers you can fly the AR Drone at eye level and carefully watch each propeller. The one(s) that are off-balance because of a bent drive shaft or warped propellers should be evident as the two blades of each propeller will look like they are at two different heights. It is highly recommended that you have a helper to do this, one to fly while the other watches the propellers and wear safety glasses!!!
To determine if the drive shafts are bent remove them from the AR Drone and roll them on a hard flat surface to determine where the bend is. You could straighten them by putting the bend facing up on an anvil with a hole in it (place the bend over the hole) and tapping it down with a small hammer. But once bent you will never be able to get them perfectly right. Replace them with either stock versions or any of the aftermarket upgraded ones (titanium versions are our favorite) for the best results.
Instability from the propellers being warped (some replacement propellers will be warped out of the package) can be fixed as well. We recommend doing the following to the AR Drone propellers from the start anyway. This will not only make the flight more stable but also cure many problems as like; Vibration in your video recordings, drifting around while hovering, losing altitude when coming to a stop from forward flight, wont climb to a higher altitude, bad flips (2.0), or acts like the motors are cutting out and dropping a few inches ever few seconds.
Note: The below procedure came from DroneBonerStallone, his original post can be found here Fix Your Props.
To start you are going to need a few “tools”. Find a decent 1980′s type hair dryer, the kind that blows your hair dry. Two 1 1/2″ (38 mm) metal tubes about 3″ (76 mm) long. A bunch of reusable or regular zip ties (the reusable ones are best as you can reuse them, but regular ones work just as well). A flat piece of metal strip 1″ X 12″ X 1/8″ ( 25 mm X 305 mm X 3 mm). A few modeler clamps or cloths pins (the wood with spring type).
Remove the propellers from the AR Drone (important, note where each one came from. some rotate clockwise and the others anti-clockwise) Use a piece of colored tape on two that turn in the same direction. Put a piece of tape on the center of the propeller and a piece on the arm of the AR Drone the propeller came from. When removing the “Jesus” clip from the propeller shaft be careful, they have a tendency to fly away…..that's when you say Jesus Christ, where did that go. And why they are called Jesus Clips.
If the tip looks flat then a little corrective action will need to be done. The two metal tubes, zip ties, and 1980′s hair dryer will be needed. Attach the two tubes to the propeller as shown in the picture to the right. Then using the high setting on the hair dryer slowly heat the tips of the blade, let it cool to room temp and do it again. You may have to do it a few times to get the plastic to relax in the curved shape. Make sure to propellers have cooled before removing the zip ties.
We Also need to make sure the propeller is flat along the leading edges. Looking at the leading edges of the propeller it should be flat along its entire length (the tip curve will be slightly above the leading edge towards the tips). See the picture below.
If the leading edges of the propellers are not flat another easy fix can be done. Get the cloths pins and flat metal strip, clamp the propeller to the metal strip as shown below (we recommend a metal strip as it helps in the heating process, a ruler can be used though). Only clamp on the leading edge, if you clamp too far in you will have to redo the tip curve. Using the high setting on the hair dryer slowly heat the blades, let them cool to room temp and do it again. You may have to do it a few times to get the plastic to relax and keep the leading edges flat. Once again, let the propeller cool before removing the clamps.
Now the propellers should have the right tip curve and be flat along the leading edges, but we are not done yet. Balancing the propellers is next. There are a number of ways to do this, but most do not balance the main gear and propellers together. We do, and this is how. You are going to need a set of parallel and perfectly level “rails” high enough to allow the propeller to freely “spin”. Some way to add weight to the light blade, tape can be used. As you do each blade temporarily remove the marking tape added when you took them off the AR Drone.
Assemble the main gear, propeller shaft, and propeller as shown in this picture to the left. Make sure the gear you use stays with the propeller it was balanced with, we are balancing the assembly and they will be matched once done.
Now we need to set up the balance stand. This is the “rails” mentioned above. A block of wood and two metal plates can be used to make one similar to the one in the pictures. The top edges of the “rail” must be perfectly level. A spirit level along the top of both edges as well as across the pair will let you know if your level.
To balance place the propeller assembly on top of the balance stand and allow the assembly to “spin” around (see picture to the right). The side that is heaviest will naturally fall low. Once you know which side is lightest you can add a small piece of tape on the under side of that blade tip.
Add a long strip of tape and trim off small amounts at a time until you get the right amount. Once the propeller sits level on the stand and does not favor one side or the other your almost done.
You could add weight with paint, clear finger-nail polish works well. Add a little paint at a time, once balanced let it dry and check the balance again.
Next you will “stand” the propeller vertical and see if it wants to fall to one side or the other. Do this with one blade high, then the other blade high. If it just stays where you put it you are done.
If the propeller tip tends to always fall in one direction you need to add weight to one of the gear spokes, if the tip falls left add to the right gear spoke, or the opposite if the tip fell right. Tape can work for this, but it might be easier to use paint.
Once you have balanced all the propellers with their gears put them back onto the AR Drone (in the correct location).
6. Constant Ultra Sound / Video Alerts.
(1.0 / 2.0) If everything was working fine before, but after a crash you are now getting Ultra Sound or video alert messages. You may need new electronics. But before you go out and spend money on any parts there are a few things you could try first.
Warning: If you are not comfortable taking apart the AR Drone (1.0 or 2.0) then get to your hobby store and let them diagnose and fix it.
Take the bottom plate off the AR Drone to expose the circuit boards inside. Then check that all the cables, wires, and connectors are tight. By just making sure everything inside is still together will solve most of this type of problem.
Also check that everything is clean and dry, canned air will clean out most dust. While the bottom is off do a short “test flight” indoors. If all the alerts are gone then reassemble the AR Drone. and enjoy the money you saved from nor buying a part you did not need.
7. All four motor LED's do not turn green.
(1.0 / 2.0) See tip 6, same type of problem normally. But sometimes the ESC's blow out. If there is a small crater on the case of the FET's your going to have to replace the ESC. See the picture on the right, the part that is in the lower right has blown a FET. That means replacing the ESC / motor assembly.
8. Other Tips
If you want to avoid a lot of the crash problems, be sure to read this Droneflyers.com article on shock absorbing landing gear.
If you have additional troubleshooting tips, please let us know. We also have a continuation and Q/A discussion of this article at our forums – please join and ask your questions. Here is the link to the Droneflyers Forum Discussion of this article.