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RE: SUCCESS! - A Brushless DF Conversion - 9/1/2007 10:32 PM   
13BRV3


 

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From: Navarre, FL, USA
Status: offline 		Greetings,

I just finished Mad Scientist Mike's brushless conversion, and it all seems to be working as advertised. So far, I've only flown it a few minutes inside, and a couple minutes outside with Ti enabled. I can't tell any difference in control, except for POWER, and I'm definitely going to have to retrain my left thumb, especially when inside. With all the swirling air inside, the DF always tends to yo-yo a bit, and I've gotten used to blipping a certain amount of throttle to arrest the descent rate. Well, the old amount of throttle blip would now require some touch up paint to the ceiling

I'm looking forward to flying it more over the next few days, but for now, I've got to get some other things done. Unfortunately, I'm already thinking of building a whole new (larger) frame, and using direct drive outrunner motors

Thanks Mike!

Rusty


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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 3:51 AM   
Old Man Mike


 

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Status: offline 		Excellent work, Rusty. A few comments:

1) Yep, the increased power is quite noticable. If you hang a payload of around half a pound on the brushless DF, the throttle will feel more like the original DF did with no payload. I've considered programming the transmitter for a little exponential control on the throttle.

2) On the ESC programming. Something doesn't seem right with the setup. All I did was follow the hookup procedure that came with the programming card. The ESC was connected to the motor as normal and it's RX plug connected to the programming card. I only had to connect the DF battery and did not have to arm it.

3) Yes, Nicad is selected because the "low" shutdown setting for that battery type disables the ESC shutoff feature.

4) I noticed that you mounted the ESC closer to the motor. One problem with that is that it addes some extra windflow resistance sitting under the blade. But your mounting does look good.

5) It will be interesting to see how this DF controller works with a larger frame. Keep us posted.


ADI: Thanks. Yes, the little Panasonic FX-07 camera does have real time video available. I considered using it with the DF SAVS transmitter or another commercial transmitter but did not have the extra payload capacity before the brushless conversion. It might be interesting to revisit it.

Mike


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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 7:17 AM   
msarid


 

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From: petah tikva, ISRAEL
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Hi Mike,Rusty&all

Please find an intersting thread to convert Berg Rx,Maybe we can use this mod to modify the DF old board?
(I have one)
If yes where is the point on the DF board to connect the PPM signal?
What is you opinion?

Have a great day
Moti


http://www.rcgroups.com/forums/showpost.php?p=7711758&postcount=2

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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 4:42 PM   
13BRV3


 

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Status: offline 		Good find Moti. That has to be what Spectrolutions is doing on the Berg boards. The only question I'd have is whether they can use the signal just as it comes from the Berg receiver, or if it has to be inverted like I needed to do with my Futaba receiver. You'll also have to figure out what they did with the antenna, to avoid having the long wire that normally comes on the Berg.

I'll attach a picture that has some annotations showing the connections you need to know about. The PPM signal comes from the receiver in the vertical board, and goes to the controller on the horizontal board. All I did was cut the pin that carries the signal, then spread it apart enough so it couldn't make accidental contact. It would be easy to bend back, and re-solder if needed. You can either connect the Berg PPM signal on the horizontal board side of this cut connector, or you can find the same signal on the larger plug on the bottom of the horizontal board.

For my tests, I've used the large connector on the bottom of the horizontal board. This gives you a handy place to pick up 5 volts and ground to power the external receiver, as well as the contact to connect the PPM signal from the external receiver into the controller on the DF.

Cheers,
Rusty (must go to the airport and quit messing with this)



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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 4:59 PM   
13BRV3


 

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quote:

ORIGINAL: Old Man Mike

2) On the ESC programming. Something doesn't seem right with the setup. All I did was follow the hookup procedure that came with the programming card. The ESC was connected to the motor as normal and it's RX plug connected to the programming card. I only had to connect the DF battery and did not have to arm it.



Hi Mike,

I guess this is a mystery like the music/LiPo cell light. There must be something different, probably with the programming card, so we'll have to wait for a tie-breaker to see which of ours is operating "normally"

quote:

ORIGINAL: Old Man Mike

5) It will be interesting to see how this DF controller works with a larger frame. Keep us posted.



For the record, I haven't actually committed to doing this yet, but I AM thinking about it. The thought would be to use similar sized carbon fiber rods (not tubes) to make longer arms. Longer cross braces would be needed as well. It shouldn't really be that hard to try. It would be easier to see, and hopefully more stable, but I really don't know if any of the programming of the controller is specific to the size of the current DF. I really don't see why it would be, other than sensitivity, but that can be changed via the transmitter.

Cheers,
Rusty (too many projects...)

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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 7:28 PM   
msarid


 

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From: petah tikva, ISRAEL
Status: offline 		Hi

The German xufo guys use the short antena(http://www.aircraft-world.com/shopexd.asp?id=3288) and the say that it work without any problems. some people rol the original antena over plastic tube and close it with shrink.
regarding to invert the PPM signal, on the xufo the Rx PPM connect to the board without inverting.
BTW what happend if the PPM signal connect without inverting.
Hope it help.

Moti

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RE: SUCCESS! - A Brushless DF Conversion - 9/2/2007 9:48 PM   
Old Man Mike


 

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Status: offline 		Hi Guys,

It appears that you can use the antenna that was used with the DF. In Rusty's picture there is the hole where I assume the DF receiver antenna was mounted (TP1). You can see the trace only goes to that black square component which I assume is a capacitor. Just remove that component and you can then cut the long white wire antenna from the berg receiver down to about a 1" length and solder (or screw secure) it to the antenna mounting point.

Mike


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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 3:40 AM   
13BRV3


 

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Status: offline 		I measured the lift of the brushless conversion by a means that I will use as a standard for my tests. Obviously, it's not an indication of what you could fly with, but it will give a repeatable number, which will be good for comparisons between props, batteries, etc. What I did was weigh the DF down with a 4 lb dive weight. The weight is in the form of a lead shot pouch, and it just sits on top of my roll cage. I put the whole thing on a scale, and read 5 lbs 5 oz. Next, I throttled it to full, with a fresh 1320 3S battery, and the scale read 2 lb even. That gives a total lift of 3 lbs 5 oz.

To complete today's lift experiment, I ran the same test with a stock DF, and got a total lift of 2 lbs 3 oz, so it would appear that the brushless motors are giving 18 oz more lift. Since the BL setup weighs a bit more, we'll call it a pound even, which is not too shabby.

Mike, have you looked into the possibility of using a higher voltage pack? I'm a fan of A123 cells, and have switched to them for everything but the DF. While they're big and heavy, they're also safe, and you can abuse them without mercy. I've flown the DF (stock and BL) with 3S (11.1V) and 4S (14.8V) A123 packs. I really haven't run the 14.8V pack much, but it did work at least for the limited time I ran it. I'm wondering if a 4S LiPo pack would be safe to run with the BL conversion. I bet THAT would have some lift

Cheers,
Rusty




< Message edited by 13BRV3 -- 9/3/2007 5:58 AM >

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 3:52 AM   
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Status: offline 		13BRV3, is that a common method for weight load testing? The reason I ask is because what you described makes perfect sense when you really think about it but it is a mind bender. I would have thought something that lifts weight would have to lift the whole amount clearing the ground or nothing at all but not in between. It's difficult to accept that some weight is being lifted even when the helo is still touching the ground, but it is actually lifting some of the weight. That is very interesting. When you think about that too much it will mess with your head.

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 3:56 AM   
13BRV3


 

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Status: offline 		The Berg have been assimilated

I happen to have a brand new Berg 4L that I ordered for the BL conversion, before I knew the Futaba could be made to work. Since Moti made it so easy for me to find the PPM pulse, I just couldn't resist trying it.

Basically, the PPM pulse is right where the referenced thread said it was, and it's actually pretty easy (relatively speaking) to solder to. I verified that the Berg PPM pulse is essentially the same as the native DF pulse, so it's plug-n-play. I cut the signal pin for channel 1 (hard to see in the low res picture), and then ran the PPM signal to that pin so I could use a normal servo cable as the connection to the DF. I already have a cable that I had made to take the servo connector to the large connector on the DF, so I plugged it in, and it works like a charm

I'm not messing with the antenna hole, but I believe Mike is spot on about being able to use the stock antenna, after disconnecting it from the on-board receiver.

Cheers,
Rusty



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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 3:59 AM   
13BRV3


 

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quote:

ORIGINAL: Sky High

13BRV3, is that a common method for weight load testing?


Beats me. I might have just invented it

quote:

ORIGINAL: Sky High

When you think about that too much it will mess with your head.


My head's messed up already, so it seems to make sense

Rusty (enjoying the FPV links)




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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 6:39 AM   
Old Man Mike


 

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quote:

ORIGINAL: 13BRV3

I measured the lift of the brushless conversion by a means that I will use as a standard for my tests. Obviously, it's not an indication of what you could fly with, but it will give a repeatable number, which will be good for comparisons between props, batteries, etc. What I did was weigh the DF down with a 4 lb dive weight. The weight is in the form of a lead shot pouch, and it just sits on top of my roll cage. I put the whole thing on a scale, and read 5 lbs 5 oz. Next, I throttled it to full, with a fresh 1320 3S battery, and the scale read 2 lb even. That gives a total lift of 3 lbs 5 oz.

To complete today's lift experiment, I ran the same test with a stock DF, and got a total lift of 2 lbs 3 oz, so it would appear that the brushless motors are giving 18 oz more lift. Since the BL setup weighs a bit more, we'll call it a pound even, which is not too shabby.

Mike, have you looked into the possibility of using a higher voltage pack? I'm a fan of A123 cells, and have switched to them for everything but the DF. While they're big and heavy, they're also safe, and you can abuse them without mercy. I've flown the DF (stock and BL) with 3S (11.1V) and 4S (14.8V) A123 packs. I really haven't run the 14.8V pack much, but it did work at least for the limited time I ran it. I'm wondering if a 4S LiPo pack would be safe to run with the BL conversion. I bet THAT would have some lift

Cheers,
Rusty





That is a good method of thrust and I did the same thing when testing the individual motors. Unfortunately my digital scale will not go above a few pounds of weight so I could not do testing with a completed bruslesss DF. I very much like the idea of comparing performance using this approach so I guess I better start looking around for a digital scale with higher capacity. I assume you were testing with the standard 12" props. I would be quite interested in the results for 11" props. I think you will see just a little drop in total thrust but a considerable improvement in battery life.

I have not done any testing at higher voltages. Off hand I don't see too much of an issue as long as you maintain some margin for the ESC Maximum 16.8v and power limitation of the motors. I can tell you that after a 7 min flight with the 21 oz payload, the motors were too hot to touch for more than a second. I'm not sure I would want to push much above that level. Of course, the new motor should be in Tuesday and I have some hope it will be more efficient in this system.

Mike




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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 7:37 AM   
Sky High


 

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Status: offline 		What are you guys planning on toting with the DF anyway? Cameras are around a half pound or less and just keep getting smaller and mounts aren't much more. So why are ya'll trying to get it to carry so much weight? Is it because it's a challenge and you have to beat it? I guess that extra lifting capacity will be good for future accessories.

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 7:53 AM   
Old Man Mike


 

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Status: offline 		Hey Rusty,

Check the mounting screws holding the motor to the adapter plate. Today I noticed that the DF seem to need extra yaw trim so I stopped flying and looked at the motors mounts. One of the adapter plate screws had come out and the second one was on the last threads causing the motor to wobble. I have now installed #2 internal tooth lockwashers and 242 Loctite on all eight motor screws. The #2 lockwasher is a tight fit but any larger will interfere with the seating of the adapter plate in the motor mount. I've also use some Loctite on the screws holding the adapter plate to the motor mount.

This information will be added to the documentation package but I wanted to give you a heads up on the issue. It might be a little hard to make a soft landing if one of the motors fall out of the mount.

Mike


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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 8:00 AM   
Old Man Mike


 

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quote:

ORIGINAL: Sky High

What are you guys planning on toting with the DF anyway? Cameras are around a half pound or less and just keep getting smaller and mounts aren't much more. So why are ya'll trying to get it to carry so much weight? Is it because it's a challenge and you have to beat it? I guess that extra lifting capacity will be good for future accessories.


A GPS system and some sort of addition to improve the visible "skyprint" would probably eat up most of that additional payload.

Of course, I still want a DF to pick up BB's T-Rex and drag it around a bit. Sure would make a nice video.....

Mike


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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 12:58 PM   
msarid


 

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quote:

ORIGINAL: Old Man Mike

Hi Guys,

It appears that you can use the antenna that was used with the DF. In Rusty's picture there is the hole where I assume the DF receiver antenna was mounted (TP1). You can see the trace only goes to that black square component which I assume is a capacitor. Just remove that component and you can then cut the long white wire antenna from the berg receiver down to about a 1" length and solder (or screw secure) it to the antenna mounting point.

Mike


Hi
The capacitor that connect in line the antena is to match the Rx antena to the DF antena so Do not remove it .
If you remove it you will reduce the transmitting range, anyway allways check the transmitting range after you modify the receiver system.

Have a great labor day
Moti

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 4:54 PM   
13BRV3


 

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Status: offline 		Hi Mike,

You're correct that I was using the stock 12" props. I might try cutting them back today, and would expect to see less thrust as you mentioned. Did you try cutting them even shorter than 11 inches? I just wonder where the optimum efficiency point is. I also wonder if we could make an adapter to adapt other props to the gears. I'd bet a real prop would be much more efficient.

I checked the mounting screws, and so far, they're fine. I'd like to replace those flat head screws with round heads, but I have no clue what thread those tiny things are. I can't find any spec for it online, and my thread gauge doesn't go nearly that small. I'm sure they're metric, but do you have any idea what the thread is?

I looked at the charts for the Feigao motors again, and they never show anything higher than 11.1 V, so I suppose that means they don't want you using 4S packs. Fortunately, the 3S packs give plenty of power for anything I can think of lifting. I did just order some long "ducted fan" heatsinks from MPI. They're longer than the motors, so they will act as heatsinks, and transfer any crash loads to the motor mounts, rather than the motors and wires.

Rusty

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 7:26 PM   
Old Man Mike


 

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quote:

ORIGINAL: msarid


quote:

ORIGINAL: Old Man Mike

Hi Guys,

It appears that you can use the antenna that was used with the DF. In Rusty's picture there is the hole where I assume the DF receiver antenna was mounted (TP1). You can see the trace only goes to that black square component which I assume is a capacitor. Just remove that component and you can then cut the long white wire antenna from the berg receiver down to about a 1" length and solder (or screw secure) it to the antenna mounting point.

Mike


Hi
The capacitor that connect in line the antena is to match the Rx antena to the DF antena so Do not remove it .
If you remove it you will reduce the transmitting range, anyway allways check the transmitting range after you modify the receiver system.

Have a great labor day
Moti


Moti,

I think you are confused. I am talking about using the DF antenna for an external RX instead of the DF on-board receiver. (an external RX module is not necessary for the brushless conversion unless you have an older DF board without the Berg receiver) Removing the coupling capacitor disconnects the antenna from the DF receiver so that you can use that antenna for the external receiver.

(and by the way, with an antenna that small, the capactor is just an coupling capacitor)

Mike



< Message edited by Old Man Mike -- 9/3/2007 8:17 PM >

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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 8:31 PM   
Old Man Mike


 

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ORIGINAL: 13BRV3

Hi Mike,

You're correct that I was using the stock 12" props. I might try cutting them back today, and would expect to see less thrust as you mentioned. Did you try cutting them even shorter than 11 inches? I just wonder where the optimum efficiency point is. I also wonder if we could make an adapter to adapt other props to the gears. I'd bet a real prop would be much more efficient.

I checked the mounting screws, and so far, they're fine. I'd like to replace those flat head screws with round heads, but I have no clue what thread those tiny things are. I can't find any spec for it online, and my thread gauge doesn't go nearly that small. I'm sure they're metric, but do you have any idea what the thread is?

I looked at the charts for the Feigao motors again, and they never show anything higher than 11.1 V, so I suppose that means they don't want you using 4S packs. Fortunately, the 3S packs give plenty of power for anything I can think of lifting. I did just order some long "ducted fan" heatsinks from MPI. They're longer than the motors, so they will act as heatsinks, and transfer any crash loads to the motor mounts, rather than the motors and wires.

Rusty


The problem with "real" props is that there are very few that are available in both left hand and right hand pitch.

Those screws are metric but I've also been unable to identify the thread or a good source. I'm just thankful that the adaptor plate came with the screws.

The new motor I will be testing this week can operate at 14.8 volts. But even at 12 volts it should be able to lift an additional 1/4 to 1/2 pound per motor.

Mike




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RE: SUCCESS! - A Brushless DF Conversion - 9/3/2007 9:20 PM   
13BRV3


 

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ORIGINAL: Old Man Mike

The problem with "real" props is that there are very few that are available in both left hand and right hand pitch.



I see what you mean. The only left and right hand props I can find in a reasonable size are wood Zingers.

Rusty



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RE: SUCCESS! - A Brushless DF Conversion - 9/4/2007 12:57 AM   
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quote:

ORIGINAL: 13BRV3

The Berg have been assimilated

I happen to have a brand new Berg 4L that I ordered for the BL conversion, before I knew the Futaba could be made to work. Since Moti made it so easy for me to find the PPM pulse, I just couldn't resist trying it.

Basically, the PPM pulse is right where the referenced thread said it was, and it's actually pretty easy (relatively speaking) to solder to. I verified that the Berg PPM pulse is essentially the same as the native DF pulse, so it's plug-n-play. I cut the signal pin for channel 1 (hard to see in the low res picture), and then ran the PPM signal to that pin so I could use a normal servo cable as the connection to the DF. I already have a cable that I had made to take the servo connector to the large connector on the DF, so I plugged it in, and it works like a charm

I'm not messing with the antenna hole, but I believe Mike is spot on about being able to use the stock antenna, after disconnecting it from the on-board receiver.

Cheers,
Rusty



Great conversion work guys ... I use the Berg 4L on my X-3D X-BL quadro ... a trick Damon mentioned in the thread for soldering the PPM pin works great ... stick a razor blade inbetween the two pins when heating up the target pin and apply solder ... the blade will block any adjacent unwanted bridging.

If you want some added strain relief, I routed the wire under the pins and it works great! ... My mod looks like this ... http://www.rcgroups.com/forums/showthread.php?p=7932505#post7932505

I just used an antenna tube to wrap the wire around ... and used a simple plastic tube to mount it to the frame ... with simple removal too ... http://www.rcgroups.com/forums/showpost.php?p=7999313#post7999313

Btw, I like the whiffle ball underside BL protectors ... I use them to protect my X-CSM frame ... http://www.rcgroups.com/forums/showthread.php?p=8008182#post8008182

--Eric--

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RE: SUCCESS! - A Brushless DF Conversion - 9/4/2007 2:04 AM   
Old Man Mike


 

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Status: offline 		Hi Eric,

Since you have been involved with the quad copter designed by the German guys, I wonder if you are familiar with the mod that was made to allow the GPS hold. If so, do you know if they used a compass module with the GPS or if they were doing it with GPS only?

Mike


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RE: SUCCESS! - A Brushless DF Conversion - 9/4/2007 3:28 AM   
13BRV3


 

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Status: offline 		Thanks for the comments Eric. I'm sure they'll help motivate the Berg converters. As for the whiffle balls, I know a good idea when I steal it

In other testing news, I shortened the blades to 11 inches, and did the max lift test again. This time, the total lift was 3 lb 3 oz, so the shortened blades have 2 oz less lift than the full length blades. No real surprise here.

Next, I thought I'd try measuring the power required to lift a typical amount of weight. My DF conversion weighs 1 lb 5 oz, so I added a fictional 6 oz to this for a total of 1 lb 11 oz as a "normal" loaded flying weight. I put all the stuff required on the scale, then subtracted 1 lb 11 oz from the static weight. Next, I ran the throttle up until I hit the calculated weight on the scale. I did the test with stock, and shortened blades.

The results were a bit of a surprise, because they were exactly the same. Both sets of blades showed 9.5A, and 90W on the meter when lifting 1 lb 11 oz. If this is a valid test, then I don't see how Mike is getting more flight time from the shorter blades. One thing I know that's different is the battery. I used a couple of fresh 3S A123 batteries for this test, partly because I was tired of charging the LiPo grenades, but mostly because my Whatt meter has Deans plugs on it, and I can't put it in-line with the stock DF batteries. The A123 cells are lower voltage than a 3S LiPo pack, but I would still think it would make a valid comparison between props. Mike's flight times would tend to disagree though

Another random note- Since I had it all hooked up, I measured the max power for full throttle with the A123 cells and stock props- 17.3A, and 160W. This is nothing for the batteries, but the 15A fuse is probably being stress tested

I couldn't quit without testing the current of the stock 3S 1320ma pack, but I could only use a clamp on meter for the test. The initial full throttle current was 18A, but fell pretty quickly to about 17.5A. I'm sure the voltage was higher, but I don't have a measurement for it.

Finally, I flew a couple packs through the DF today, and have to say that it's probably the smoothest, and best behaved flights I've had. One flight had a margarine tub hung below it as a test, with maybe 5 oz total weight in it, using the stock blades. The other flight was just the DF, with the shortened blades. The extra power is really nice, particularly for vertical descents. I took it up to about 30 ft, and cut the throttle, then went wide open at maybe 15 ft. The DF stopped at about 5 ft, and rocketed back skyward. The LiPo was almost too hot to hold after that flight, and was even slightly puffed, though it went back to normal when it cooled a little. I'm thinking a 20 amp fuse, and higher current capable batteries may be in order.

One other interesting tidbit- I haven't had a single power loss since I changed to the 2.4 GHz Futaba receiver. Before that, I had them on virtually every flight, and even talked to Spectrolutions about sending my board back. I'm tempted to switch to the Berg that I converted, just to see if the problems come back on 72 MHz, but I'm not too motivated to test that theory

Cheers,
Rusty


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RE: SUCCESS! - A Brushless DF Conversion - 9/4/2007 3:38 AM   
Sky High


 

Posts: 1514
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Last Login: 2/22/2010
From: Atlanta, GA, USA
Status: offline 		Has the intermittent power loss issue that so many have been experiencing been resolved yet?

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RE: SUCCESS! - A Brushless DF Conversion - 9/4/2007 4:22 AM   
Old Man Mike


 

Posts: 267
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Joined: 4/21/2007
Last Login: 11/21/2008
From: Huntertown, IN, USA
Status: offline 		Hi Rusty,

Interesting measurements. I have a few questions:

1) What wattmeter are you using and is it showing peak current or average? Remember that this modification is a bit abnormal from other Brushless systems. With the PWM input to the ESCs, the current is running at the same peak current at mid thottle as it is at full throttle. The difference is the duty cycle is higher at full throttle.

2) I used a series 0.15 ohm resistance in line with the ESC input and monitored the voltage drop with the oscilloscope. The current peaks were 3.9 amps at full throttle but that was still not at 100% duty cycle.

3) I've run several tests at near full throttle for up to 7 mins flying the 21 oz payload and have yet to blow the 15 amp fuse. That is what I would expect to be able to do if the peak current at each motor at full throttle is 3.9 amps and the duty cycle less than 100%. Do you really think that the 15 amp fuse would still hold at 17.3 amps?

4)
quote:

Both sets of blades showed 9.5A, and 90W on the meter when lifting 1 lb 11 oz.
If those numbers are correct, then the battery voltage is dropping to 9.5 volts for that 6 oz payload. My system is above 10 volts even when lifting more than 3 times that payload. Something is not right or those batteries do not perform anything like the 1320 mAh lipos.

5) Have you tried comparing the flight times for the 11" vs 12" blades with a 7 oz payload? I've done it half a dozen times and consistantly get significantly longer fly times with the shorter blades.


I'm glad to hear that your dropouts have disappeared. I can not say that here. I thought I had seen the last of the dropouts after flying for several days without a single one after the brushless conversion. Then I had three of the 0.8 second drops occur during the first few mins of a flight. It has not occured since. (as I think about it, that flight was with the motor that had lost one screw and was loose in the mount - makes me wonder if that was a factor) That is one erratic and elusive problem. Since the effect is exactly the same with the brushless motors, it must be that the PWM just stops for that 0.8 second period and then returns to normal. The little bit of information I got from Dammer is that the 0.8 second period would be expected if a glitch was received on the PPM input or power to the microcontroller. Maybe the 2.4 Ghz output is processed for a cleaner PPM stream.

Mike


< Message edited by Old Man Mike -- 9/4/2007 5:32 AM >

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