kg4izw

I just got my first DF the other day off Ebay and I am already having a problem. One of the blades is not spinning properly. Here is what is happening. When I give it light throttle, sometimes all the motors spin normally, but sometimes the front one does not spin at all until I give it LOTS of throttle. If I hold the DF down, and give it throttle, then this motor sounds like it has the hickups. It cuts out and then back in with me NOT making any changes on either stick. I hope this is a defective motor. Anyone have any ideas? If I try and get it up in the air, even just a little, that same motor cuts out and falls back to the ground. Thanks. Paul B.

Sky High

Well, it is normal for certain motors to spin a little faster than others for flight to be possible but if the front motor is just stopping all together, that's not normal and is probably because the motor is failing. First make sure your tilt trim is not set to extreme rear pitch. If you don't have a new motor on hand, I would suggest that you switch a known good one into that mount and put the bad in the other and if the good one works in the front and the other still doesn't function properly, it's a bad motor. If both motors work, then it's a board issue.

kg4izw

I sure hope it is a motor.
I will try to do the swap this evening.
Also just wondering if you guys know of anyone who has a DF in Birmingham, AL ?
Thanks.

Sky High

I was in Birmingham for helo fun fly this past Spring. I was the only DF pilot there. Here is the story.

www.rcuniverse.com/forum/m_4053559/tm.htm

kg4izw

I did the motor swap and the problem has completely vanished !
It must have been a bad solder connection.
This thing is amazing!
Flying a DF is so much better than a normal electric helicopter.
It seems like I am dont even have to fight the ground effect that is normally a nucience when learning to fly.
I'm about to read your story, SKY.
Paulb.

kg4izw

UPDATE:
The problem came back and I called Spectrolutions because I was sure I was going to have to ship away the board. They told me to bypass resistor #r29 and see if the problem goes away. I did this and the problem has been gone for a week. They told me that on my board that the #r29 was on the edge of the board near one of the landing supports and that when the board gets flexed the resistor breaks and gets a small crack that is not noticable with the human eye, but could cause this intermittant problem. I bridged the contacts on both ends of the resistor and it is fixed. He said this was a common problem and they have since relocated that resistor to end this issue. I become more and more impressed with the flying capabilities of this helicopter as I get more confident with its use.
Also: I am still 100% satisfied with the high level of support I get from both RCTOYS and Spectrolutions. And they are giving me free support on a product that I did not even buy from them. I bought it off Ebay. Thank you

Sky High

You must have one of those worklights with a built in magnifyer because those resistors are little bitty, bitty!! How did you do what you mentioned to them so precisely?

MoBiggz

I had the same problem with mine and just sent my board back in. I worked with DFI to re-heat some of the gyro solders and a few other solders but I didn't have any luck. My post about it is [link=http://www.rcuniverse.com/forum/m_4733255/tm.htm]here[/link] but for now I have sent my board to Mike at Spectrolutions. I did take some macro pictures of the soldering points that they wanted me to reheat. I'd be happy to post them if anyone is interested. This issue is for rotors not spinning correctly and intermittent motor cut outs.

kg4izw

Sky, you are right about the resistors being very small. I dont have any special equipment and the only electronic knowledge is what I have learned as a HAM Radio operator. Anyway, all I did to bridge the resistor is put a long skinny lump of solder across the resistor so that it contacts the board on both ends. Voila. Problem solved, well at least that problem solved. I now understand why they use that resistor in the first place. I am now getting anywhere from minute to quite considerable radio interfearance on that particular rotor. Sometimes it makes the DF shudder a bit, but one time it dropped 2 feet in the middle of the air and then recovered. That was SCARY.
Paulb.

Sky High

When you say it dropped, do you mean with no power or when it seems to just lose lift all the sudden from a hover? If it falls while under power, [link=http://www.rcuniverse.com/forum/fb.asp?m=4752474]this[/link] is a possible explanation and has happened to alot of us.

kg4izw

There was definately a drop in motor speed. It was no more than 20 feet away from me at the time and I could hear the change. I was just talking with my wife today about your other post about the hover drop and how sometimes it would fall and sometimes it would rise under the same amount of throttle, and she has noticed that phenomenon as well as I.
I have not decided whether perfectly stable flight is important enough to send away the board, be without my DF and pay $50. Unless the problem worsens I'm just going to keep it as is.
paulb.