Still missing.. and continuation

 

Yesterday I was out with a few relatives again to try and find the X550. No luck but must my posters are still hanging on the trees. My strongest guess is still that it's stuck in one of the trees at 15+ meters. However, due to the thick leafs it's quite hard to see anything. I'll have to wait for the leafs to fall off this fall and have a return trip to see if it's possible to spot it.

In the meanwhile if I get no word from any by-passers in a few weeks and as I still have a lot of parts and utilities, I think I'm going to start building a new quad. Almost half of what I've so far invested into this hobby are things such as battery chargers, spare parts, spare propellers and so on. This means I can probably put one together with not too much money.

What I'm missing are electronics and motors, which at most add up to a little more than $150. What I will further invest into and which would have saved my X550 that's done MIA is a radio linked telemetry system. It would have broadcasted it's position and I'd been able to find it easy. Now there are a few ways of solving the telemetry.

3DR $86

One way is the all expensive 3DR Radio Telemetry Kit seen to the right. It costs $86 and would probably do it's job in excellence. But as I'm still aiming for a shoestring budget, I'm sure there are alternatives.

Below are two low cost alternatives. They cost less than half of the original 3DR but should do the job. I've read a blog post regarding the APC220 about how to connect it properly. The third option I found yesterday browsing the web. I have no idea if it works but its branded as the 3DR with a different price so I guess it's a copy. But might still work as well as as the original.

3DR copy(?) $36

APC220 $33

In short, the X550 is still MIA

 

As the topic says, my X550 is still MIA. The day before today, I went to a library and produced these posters and have put a bunch of them up on trees in the area where it disappeared. Today I also filed a report to the local police department regarding my loss hoping that if someone turns it in, the report will be recognized. My hopes now stay with possible by-passers that happens to spot my quad and hopefully makes a phone call. 

And no, it's not my real phone number. It's juts prepaid number I acquired for the poster that I'll terminate once it's no longer required.

Stay tuned! All hopes aren't gone yet.

RTL fly away...

Yesterday I went away to find a field large enough to do some serious RTL (return to launch) and navigation testing. This requires space without trees too close. I found some nice fields and started testing. I successfully tested both RTL and three way point navigation before my last RTL went sour...

I flew quite far away as I previously had done and hit the RTL. The normal procedure then is for the quad to gain height to 15 meters, which is default. Then head to its home position and descend to about 3 meters and loiter. This time, instead of turning towards home, it started drifting to the left. I quickly intervened to save the quad by counter steering rightwards. The quad then rotated 90-180 degrees making the direction impossible to see from this distance and disappeared behind those trees according to the drawing. I then ran towards the highway and never saw it again.

I've since then been covering the grounds around the point where it disappeared for about 8 hours in total, checking trees and the ground where it might have crashed without result.

It might have kept going in that direction ending up on the other side of the field as the program does not include anything about landing, but keeping 15 meters until the destination has been reached. It might also have taken a short trip on the field, then turned around ending up somewhere else. I still think the highest possibility is that it sitting in one of those trees along the highway.

Later today or tomorrow, I'm going to print posters asking people to contact me if they find my quad. Hope that gives some results. At this point, I don't think I can afford a new one, which leaves me with a pile of spare parts that will not be used..

The new propellers was a success

Last night I tried out the new 8 inch propellers along with a fresh motor to replace the last faulty one. The x550 now spins like a cat and flies like a bird. I trimmed the flight controller for the new propellers, which wasn't all that much to change and it's very stable.

After the basic trimming I started working on navigation and RTL (return to launch). These also has a set of P, I and D parameters for navigation. There is a good guide over at the ArduCopter wiki. However, I didn't have much success in trimming the RTL and the x550 always overshot or navigated wrong. Once both batteries were drained, I figured out that I'd trimmed using wrong parameters, dooh! I had been trimming the HLD_LAT/LON instead of LOITER_LAT/LON. Will have to do this at some other point where I can find a good field to try it out at.

Link to the guide: https://code.google.com/p/arducopter/wiki/AC2_loiter_PID

Packages packages, more packages and washers

 

This came in the mail today. It's the order for new motors and 8 inch propellers. Having smaller propellers also eases the torch on the motors, which should lessen the overheat.

Now I might have come to a conclusion why my motors are failing. Due to the nature of aluminum, its quite weak. Now as the screws that hold the motor in place slightly bends the aluminum inwards, the top of the screw seem to get scewed too far into the motor and may cause a short circuit.

To counter this condition, I've bought some washers. These washers are used both to protect the aluminum from bending too far and also to put some distance between the top of the screw to the motor. I also bought some locking washers to keep the screws in place keeping them from coming loose due to vibrations.

This is the end result, now only time can tell if it works or not. Will try this out tonight along with the 8 inch propellers.

What does it weigh?

It's always essential to know what your model weighs. This model seem to weigh 1.3kg. My own estimations was 1.1kg given the weight info given for the parts used.

During test flights it have been able to sustain almost 16 minutes of flight time. That is using 1200kv motors with 9x4.7 propellers. I'm however intrigued to know what the data will be using the 8x4.7 propellers that are soon to arrive. I want to try the smaller propellers as I still feel that the motors are over performing given the model weight.

Malfunctioning motors

This is the video that I just recently submitted along with a support request to maybe get some new motors. You can see from the top left, to the bottom right motor 1, 2 and 3 not running properly.