l8braker

Hey guys have you ever experienced radio loss? While flying recently I've had some glitches where it completely looses signal for 1-2 seconds. I've been able to recover from ever incident, but I'd like to eliminate this issue. Typically my DF will shut down and free fall until it picks it back up. This isn't a fun feeling, but I've been lucky to correct it. The most recent problem above several trees [X(] .

Are there any Spectrum radios that will work or better crystals?

laceycopter

Spectrum is totally different and will not work with the DF board. Wish it could be converted, everthing else I have is on a Spectrum.
You might wants to check some back posts or maybe Sky will jump in here. I think he was having the same problem and it turned out to be a bad battery connection (but I'm not sure).
Check all your connectors and make sure the posts on the board where the battery plugs in are good and tight and that the solder isn't cracked.
Good Luck,
Lacey

Sky High

Well l8braker, I see it finally happened to you too. That's what I mentioned in your video thread about your DF flying so solid. Alot of us have experienced those momentary losses of power lately. My SAVS with a new board fell straight to the pavement from about 80-100 ft a few months ago and it was totalled. I'm going to post the POV video and what it looked like on the pavement. What makes my crash so strange is that I had flown there before with no problems. I very rarely experienced that problem with my first board back in 2005 but only started experiencing it with newer boards in the past 6 months or so. That first board has at least 200 flights on it too. I would recommend that you fly yours in an isolated area where the chances of RF hits are near none and see if it happens there. Someone mentioned that DFI is using a new receiver called Berg and that it supposedly allows for the use of different frequencies. I also wouldn't fly too low over trees with that happening so you'll have time to recover if it happens again. My DF has been in the top of a 60 ft tree and it's not fun at all.

l8braker

Yeah I'm more cautious now for sure! Used to I had no problem being over the trees. Maybe in some of my first crashes I jarred something loose. I'll check for loose solder around the battery connections/board. That would be a very easy fix. So far I've had no recovery issues, but if it lost power longer than 3 seconds it could easily be fatal. Still I had it fall from 60ft to 40ft and barely cleared the trees!! [:-] I didn't know if anyone had changed channels/crystals/radios, but it sounds as if they only work with the factory stuff.

Also I've been trying to upload the night time video of the DF with LEDS but RCU videos isn't working for me???

Old Man Mike

I thought that the loss of signal safety feature (you know how they demonstrated it by taking a sledge hammer to the transmitter) would prevent a total loss of power if the signal was lost or blocked by interference. Since I just received my first Draganflyer a few weeks ago and bought another complete set of parts to build another, I am quite concern about this news. I have over 30 years of radio and electronic design experience so perhaps I can be of some help here even though I am just a beginner R/C pilot.

Mike

techrtr

Mine started having those funny power losses too. Never seems to happen when I take it really easy. When I start to throw it around, it starts up. Thought it might be a battery but then I tried a new 2080 mah thunderpower and it actually seemed worse.

Old Man Mike

I asked the technical folks at draganfly if the receiver board that I just ordered would be the same as the one I received a few weeks ago. He had me check what was on that vertical printed circuit board. If that board has a small pc board (mine is actually wraped in heatshrink) which is plugged into a black connector, then the receiver board is the most current design. He said there were some minor improvements made but would not go into the details. SkyHigh, I wonder if you have this most recent design.

Mike

BB_DF

It is very challenging trying to integrate RF components near logic components on PC boards. With your experience, Mike, I'm sure you can attest to this. If it tends to glitch when you're hotdogging it, techrtr, it sounds like motor/ESC noise getting into the digital circuits. Recent studies have also determined that graphite components can generate interference under certain vibration conditions. We once had a board that would reset itself arbitrarily, sometimes after an hour, sometimes after a week. We never could track down the problem and finally had to redesign the whole project using a 6-layer PC board with massive ground plane layers between the logic layers. RF/Digital integration is not for the weak of heart.

Another issue with the DF design is the lateral force of the vertically mounted board and its components performing unnatural acts on the connectors during abrupt maneuvers or harsh landings. Look at the way the Germans are mounting their PC boards on the UAVP & Q4 designs. They look like something out of Mad Max.

It's been about 20 years since I've flown model helicopters (since been flying "full scale".) Some things have improved a lot, but it looks like some of the frustrations still remain...

Cheers,
Bruce

Sky High

Well, I don't think the DF is losing signal from the Tx because then it would go into auto land. The factory setting for that is full throttle with a gradual reduction. To see this function at work, either weigh or tie down the DF with something and turn off the Tx while the DF is armed and on the ground and see what happens. It will scare the #$!% out of you! To recover just turn the Tx back on. [link=http://www.rcuniverse.com/forum/fb.asp?m=3746141]This[/link] is what happened to me with LOS. You can program it with custom stick settings for auto land. Anyway, I think the issue is just power interruption to the motors but not to the receiver because if the receiver loses power, the board resets and nothing is going to save you then.

No, I don't have the latest board with the Berg receiver. Can you post a picture of your board?

l8braker

Yeah that makes sense Sky, after power goes back to the motors everything is fine. I checked mine over for any loose connections/cracked solder and nothing! Guess I just need to be careful. I did find a little slack on the board holding tabs, so maybe it was slightly moving around causing havoc. I'm only talking about the tiniest of movement though.

I keep searching to find some better motors, but haven't found any. I've seen the motors listed as 280/370/380 all from Mabuchi, but which is it???

BB_DF

That makes us feel SO much better!!

P.S. If you'd like I can take pictures of the controller boards when my SAVS is delivered next week. I know the shipment was held up in Canada pending delivery of boards from Spectrolutions.

Old Man Mike

Here you go:

[link=http://af9y.com/dfberg.jpg]Draganflyer Berg Rx[/link]

By the way, I'm most impressed with what I have read about the Berg receiver. It is amazing to me that they can provide so much capability for $50. I think I'll buy a separtate Berg Rx module for some detailed testing of the performance.

Mike

l8braker

I just bought my DF Ti about a month ago, and I didn't get that Berg RX. hmmm wonder what I can do to upgrade?

laceycopter

Just wondering is everybody having this power problem with TI on?
I only tried TI a few times and I didn't like it (wobbles and lack of control feel) I have never felt a power interruption and my SAVS is like a year old now with over 400 flights. I get about 75 to 100 flights on a set of motors and I'm running TP 2100 mah batteries.
Lacey

Sky High

Flying over trees isn't the problem. It's being over the trees when that power issue happens and dropping a few feet before it recovers. If you're not high enough over them when it happens, you're going to be calling a bucket truck like I did [link=http://www.rcuniverse.com/forum/fb.asp?m=3746138]here[/link].

Old Man Mike

Does anyone have a picture of the older Draganflyer board so that I can see what it looked like before the new Berg Rx?

Mike

Sky High

Thanks for that picture Old Man Mike. That is interesting. I've posted plenty of flight board pictures of the pre Berg version. I'll try to find one.

BB_DF

Many people have said they wish the DF would go to the Spektrum Rx/Tx, but I read on another forum that the 2.4 GHz cameras have interfered with the Spektrum Rx. Technically this should not be happening, but with the close proximity of the antennas and maybe less-than-perfect QA on the camera transmitters...

Sky High

Here is a picture of the board before the new Berg receiver.

l8braker

My board is just like Skyhigh's.

Lacey I have had the issue with TI on only. I haven't flown near as much without it, so maybe I'll try that, and actually learn to fly better hahaha.

13BRV3

Very interesting about the new board. I just emailed Spectrolutions about upgrade options, and I'll post their reply if they allow me to.

I'm most interested in the possibility of using a Futaba 2.4 GHz receiver instead of the Berg. It appears that they've made the board with a nice header for all the receiver connections. If that's true, then it should be possible to use any receiver, custom wired into that header.

Stand by,
Rusty

13BRV3

Here's my question and answer email to Mike at Spectrolutions. This is posted with his permission.

-------------------------------------------

Greetings,

There's been some talk about recent changes to the DF which include a Berg receiver, rather than the one built on the vertical board previously.

Is there an upgrade available to get the new receiver?

If so, how much does it cost?

Is it a significant improvement?

Most importantly, with the new board, would it be possible to use other receivers as well? Particularly, I would like to use the new Futaba 2.4 GHz system. I'm 100% sold on 2.4 GHz systems. My R/C field is plagued with interference problems for the 72 MHz freqs, but I've been completely clean with my new 2.4 GHz stuff. It's been so great that I got rid of all my 72 MHz stuff about a week after trying the new radio.

Thanks,
Rusty

---------------------------------------------


Rusty,

Yes we have changed production to a Berg receiver, but it is not a standard Berg receiver, you cannot just buy one off the shelf and plug it in (or any other receiver for that matter).

The reason for the change was primarily due to a parts shortage for the original design that we started to encounter early this year.

We are also hoping that since it is now separate from the vertical board, that it will be less likely to get damaged during a crash like the original receiver had a habit of doing.

It is possible to convert the older boards to this design, although we have not yet determined a price for it. It would be under $100 though including the receiver.

Best regards,
Mike Dammar
Spectrolutions Inc.

l8braker

hmmm no mention of improvement or upgrading to 2.4ghz/spectrum. I would be interested if there was more information on this. Thanks for posting and keep us informed.

Sky High

According to the picture, it looks to me that the Berg Rx is still connected to the vertical board so what is Mike talking about how it's not? DFI told me that the heat shrink is to help keep the crystal in place.

marty103

Did you or anyone find the problem with intermitting loss of power? I'm having this way to much for me to fly more than a few feet off the ground..
I order new motors today because I noticed the left motor 30 to 50 per cent hotter than the other three.
I also held it and gave it full throttle after such events ,but today when I did this I noticed the left motor would just turn at full throttle.
Shut it off and turned it back on and rearmed and the motor ran fine.. Hope somebody has the answer..

Thanks in advance for your help!
marty