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View Full Version : Hmmm... This Seems Familiar...


fr4nk1yn
04-10-2008, 05:48 AM
A few months ago my Me-109 went down.
I thought I I lost all control while the motor stayed running.
I eventually blamed it on the 6100e RX browning out from my stupidity of usinh too many servos on a TBird9.

While flying my Harpy-Cat tonight I had a very similar crash happen.
I was flying "slow" circuits a little less than half throttle.
KA450H with Graupner 4.7x4.7 with a cheap 25amp ESC that's worked for quite a few flights with the motor and a 1800mAH 3s, also use before with the motor and ESC.
I had a "glitch" and I believe went into failsafe because the motor shut off, I bind the motor off in failsafe, and the plane held it's line until it recovered. It felt like a couple seconds I'm sure it was less.
Instead of bringing it in I assumed the 2.4ghz system surely wouldn't "glitch" again.
It did. Flying away from me the motor stopped and no control while I frantically tried every direction. It recovered long enough for me to get the plane turned back toward me before it cut out again. This time it's not gliding it's spiraling. It recovered again but it was too close to the tress to save it, it went in. I was able to find the plane in the brush since the motor was still working afterward.

Not too bad really, it's fixable.
It's just really similar to what I thought happened before.
The RX has been fine, since the 1st crash, I've flown this motor, ESC, battery and RX combo without problems maybe a dozen times.

The weather was quite damp outside, just adding that I don't know if that could've contributed.

One thing that was different. The plane used 3 GWS servos instead of the 2 S-75s in the other planes.
This ESC has been used with as many as 4 servos before with a 2200mAH battery but the motor didn't pull anywhere as much power as this.

fr4nk1yn
04-11-2008, 01:31 AM
Ok Got a bad range test on the RX. Found the cause.

firemanbill
04-11-2008, 01:34 AM
Well at least you know what it is! I hate it when stuff like that happens and I can't explain why...:(

fr4nk1yn
04-11-2008, 04:25 AM
Wow! My typing is so bad I won't post tonight's crash (:

GreenAce92
04-11-2008, 05:08 AM
AHA! Dx7's going bad,,, the good ol' 72 triumphs! ANd its cheap!
Sorry to hear about your problems hope you get it all worked out.

buzzbomber
04-11-2008, 03:35 PM
AHA! Dx7's going bad,,, the good ol' 72 triumphs! ANd its cheap!

I don't think I'd go that far......I've had my share of problems on 72mhz, ESPECIALLY with electric planes generating much more interference than glow.

fr4nk1yn, glad you found the cause. Do you think it was an installation issue or a problem with the receiver itself? I'm relatively new to 2.4ghz, so interested to hear from someone who had a problem and actually took time to diagnose it instead of crying about low voltage, the issue du jour. FWIW, I haven't had any issues yet since switching over, and I can't wait to retrofit all my single conversion and micro rx planes to the new band.

fr4nk1yn
04-11-2008, 06:57 PM
I'm on my phone so expect typos: I called Horizon and got put on hold for awhile' I have unlimited internet but not calls' so I hung up. Ifll shoot them an email. I really want to range check my AR7000 to make sure it's not the TX first though. It was not due to the plane. After the crash I removed the RX ESC and a servo to test it was still glitching at 30 feet. I have been worried abouth the antennae on these RXs so I used nylon tubing a toothpick and heatshrink to brace them. I need to remove that and test again. I've used heatshrink and toothpicks before but not the tubing. Now on to the crash:

fr4nk1yn
04-11-2008, 07:16 PM
I get to the field last night and there's two guys flying a Zero. I get out take the plane out the hatch and start doing my range testing. Failed. I'm moving the RX and thatjs when they brought out the Stryker. I got a good' one' range test so I was gonna go. They asked what the plane was called "Harpy-Cat". I'm being so cautios they ask if it was my first' oh no. The launch is scarey' as most are' I get it settled turn off the up trim with the flap switch and trim it. There watching so I'm making some fast passes' the plane runs out of field fast so I have to take it a little higher to stretch her out and build some speed. I'm breaking up the fast runs with some SLOW laps' this plane just should'nt fly this slow (: On one fast pass I pull up and the plane excellerates up until I panic. If it glitches now I could drive home before it hits ground. While it's GOING UP i HEAR THE guys say something. I slow her down again and SLOWLY spiral down to tree level and start again. This battery give 8 minute flight times. Then while in a high speed turn it locks and falls out of the turn into a perfect dive. I had to puull the pointy nose out of the groud. BUT it was still fun. DISCLAIMER: I fly in a field in an industrial area besides the vertical climb' and how far it could've traveled on the way down ther was little chance of anybody being hurt. I kept it away from me and the two guys.