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Showing posts with label Blade4503d. Show all posts
Showing posts with label Blade4503d. Show all posts

Monday, June 2, 2014

Second outing with the heli = disaster

Saturday was a beautiful day for flying. Sadly, it did not end well.

I charged up the batteries in the morning but then it got windy by the time they were ready. Later in the evening, the winds calmed down to around 5-10kmh so I decided to take the heli up to the park and get airborne.

The first flight went pretty good. There were a few scary moments, but no crashes. I felt pretty good. Here's a clip from that flight.


The second flight went really well, again with a few scary moments, but ultimately ended in disaster.

I'm not sure what went wrong, but I'm fairly certain that landing with stunt mode turned on was a big part of it. I'm pissed at myself too because I was thinking the whole time that I should turn it off before landing, but I was worried that turning it off might result in a sudden drop in altitude and possibly crash.

Oh, the irony.


The end result was the loss of half of the tail rotor assembly. It flew off when main rotor blade struck the tail boom and bent it. This also fractured one of the main rotor blades. I found half of the tail rotor about 20ft away. Couldn't find one of the blades.

Bent tail boom
Broken tail rotor
The fly bars got bent nearly 180 degrees. I should have taken a photo before I straightened them. It was crazy.

Flybars after I straightened them. They'll need replaced.
That was my initial assessment of the damage.

Later in the evening, I discovered more. The main rotor gear was stripped.

Stripped gear
Last night I placed an order on Great Hobbies web site for pretty much anything that had to do with the tail assembly, since I'm not sure what I'm missing or what, if anything, is salvageable from the pieces I have. I also ordered new main rotor blades, flybars, and the main rotor gear.

This afternoon I dug out the CD that came with the 450 and watched a few tutorial videos on repairs. One of them made me wonder if there may be other damage that isn't immediately obvious. I looked over the injured bird and discovered more damage. :(

The spindle/feathering shaft is also bent. It's not obvious in the photo because you can't see it, but a tip I got from the video showed me how to determine this.

The shaft runs inside the two blade holders.
I also found that one of the servo control arms must have been cracked because when I inadvertently pressed lightly on it and snapped it. I wonder if that was from this accident or the last? It's scary to think that this could have snapped in flight after the upcoming repairs.

Broken servo arm.
Inside one of the other servos, a gear (or gears) sound like they might be stripped. There's a grinding sound and feel when I move that control arm.

Pretty sure the gears inside this servo are stripped.
I found the additional parts on Great Hobbies web site and phoned them to see if they could be added to my pending order. No problem. They'll all be shipped out today.

I don't think I'll be taking off or landing on grass anymore, and while I'm sure it's possible to land while stunt mode is enabled, I won't be trying that again either. It doesn't take much to forget that pulling down on the throttle in stunt mode doesn't mean shut off motor. I think I may have done that. Maybe I'll just leave stunt mode off for this year.

Tuesday, May 27, 2014

Maiden flight not so good

After countless hours flying the RealFlight 7 Sim, I was ready to take the Blade 450 3D out for its first flight on Saturday. With hardly a breeze in the air, the conditions were ideal.

I decided to use my homemade training gear. Unfortunately, the grass up at the park where I used to fly my plane was in need of mowing, and I stupidly decided not to start off on the paved parking lot. This was mostly because it would have put me in view of a group of people at the far end of the lot, and I wasn't ready to have an audience, except for my long-time friend who came along to watch. But long grass meant I had to get more altitude, which defeats the purpose of using training gear. Duh.

I think the flight last less than 3 minutes before ending in disaster. I'll let this edited video speak for itself.


The end result was a broken main rotor blade holder, which cost me less than $10 to repair (pack of two!), and now I have a spare in case it ever happens again.

Green: The part. Red: Where it broke.


Repairing the heli wasn't as easy as I expected. Blade provides you with the tools for the heli, but what they don't do is provide you with two allen keys the same size that are required to remove the blade holders. You need one for each side as you unscrew one, so it doesn't just spin freely. Thankfully, I did have another in my tool box.

After the repair, I ran the prop for a few mins as fast as it would run without taking off, since I was doing this on my front walkway and that would surely have ended on a bigger disaster. It seems to be pretty stable.

So, what's next?

Either I'll try the training gear again, but this time on pavement so I don't need to lift off as high and have more time to get comfortable with the controls, and trim it properly... or, I'll skip the training gear and keep it higher and fly in a circle or oval, rather just hover.

One thing I noticed with the RF7 sim is that I often find it easier to fly around than simply hovering. Keep it moving forward and worry about altitude and and roll. Hovering seems to require more concentration, for me anyway.

As a side note, when I was testing my repair I noticed something odd about two large gears that drive the main rotor blade and gyro. (I don't know their names off-hand)

The two gears, after I removed the obstruction.
 It looked like they were attached so they would spin at the same speed. Now, I don't know very much about the inner workings of these yet, so I wasn't sure if this was by design or if something else was broken. When I turned them by hand, that confirmed that they do not turn at the same rate. Upon further inspection, it looked like something was jammed between the two gears. This is what I removed.


A broken tie-wrap.

I looked over the entire helicopter and there doesn't appear to be anywhere that may be missing a tie wrap. Every wire is secure. I don't think this came off during the crash. If it didn't, then that means it was there the entire time. Could this have affected the stability of the helicopter? Perhaps. The controls didn't feel bad to me, but seeing as how my heli experience up to Saturday was on the sim, I'm not sure if I would have noticed the difference.

Hmmm...