jesolins

Hi Gents,
Point of order regarding previous posts in this thread... During a normal front=sky, rear=ground TI calibration, the rear and front thermopile sensors are looking for (IR) temperature differences and holding that in memory for use as ground is X-temp, sky is X-temp. Then the processor uses that to figure along with the right stick down and to the right level cal as constants. So in flight it then calculates, if the (IR) temp on my left is less than my right I need more speed on X-props and less on Y-props, etc. Bottom line...If you calibrate the DF sideways, you are doing it wrong.
There is some good info on DF and TX exponential and EPA and dual rate setup, even though it is the brushless version, in this thread over in rcgroups: http://www.rcgroups.com/forums/showthread.php?t=768115
As for the glitching you are seeing, after checking your brushed motor caps as was suggested, I strongly suggest you check the diode between the riser and switch on the DF board: http://www.rcgroups.com/forums/showp...&postcount=941 and here: http://www.rcgroups.com/forums/showp...&postcount=982 That diode's solder joint can be cracked by the riser/vibrations/hard landings, (on all my boards it was originally mounted up against the riser which tends to vibrate and bend in "hard landings", causing the diode's solder joints to eventually fail. That will supply intermitant power to the DF board and cause glitches/crashes/resets. It is worth the effort to remove the switch and move the diode over farther away from the riser and towards the switch (it is hard to see between the slide switch and riser on the left rear of the board).
Other hints, put an aluminum bar stock roll cage or thick coat hangar wire cage on to protect the board. The receiver antenna is a mere 1/32 wave length with no loading! Wrapping a 40 inch length of antenna wire around a straw is better than the stock setup. Too much TI sensitivity dialed in is not your friend, especially in winds gusts 15-20k. Turn the TI sensitivity lower in those conditions or if flying near trees and buildings. Note that there is a warning in the manual not to turn TI on or off in flight. There could be a very different trim requirement for each and turning it on or off inflight "could" cause a crash. TI is something that works great to assist you in hover when the DF is just a dot in the sky waaaay up high.
Cheers,
Jim

ericlawrence

Hello jesolins: Thank you for the information. I am a bit confused as to what you mean by calibrating sideways. I am arming the bird holding it straight out in front of me with the eyes up. Is this correct or is there another way for better reliability. Thanks - - Eric

jesolins

Eric,
You are correct. The TI cal procedure is as the manual describes. I was referring to earlier postings in this thread.
Here is a DF flight checklist: http://www.rcuniverse.com/forum/m_6868113/tm.htm
Cheers,
Jim

ericlawrence

Hello Jim: Great information. I picked up a couple of valuable tips not found elsewhere. I was standing in front of the bird to teach it level. I will try standing behind it and see if that helps with the wobbles. One question. You mention arming the TI, then suggest recalibrating the trim again without TI. I did this and when I went back to flying with TI I still had major trim adjustments to get the bird to hover. Did I get something wrong? I have two VTi's and flew one in the wind this day (I live in the mountains where it is generally windy) without a mishap. I have yet to get the confidence to fly high enough to take photographs. Perhaps soon with the new insights. Thanks again - - Eric

jesolins

Eric,
First fly and trim with TI off inside(what I prefer to eliminate dealing with wind/breezes) or outside. Then, when outside on a one or two green LED TI type day, do the proper TI cal as in the checklist or manual. You will still need to trim again for the difference in flying with TI on. That is why it is not recommended to turn TI off while in fliight. After you get it trimmed at 10 feet or so, go up to 20 feet and see if it needs any more trim adjustment. If it is good there, then it will stay in good trim at even higher altitudes. When you have it well-trimmed, you can then land and press the arming button while putting in some left yaw. This sets the fail-safe trims in case of signal loss. ***WARNING!! Do not try to test this so called "failsafe mode" by turning your TX off as you will see it go almost full power in the air or on the ground before it decreases power to come back down. I just had a nasty experience last week after flying it where I accidently turned off my TX after I landed it befroe removing the DF power. It just went to full power and I tried to catch it as it was next to me. Mine is brushless with the stiffer EPP1045 props, so they were able to cut through my forearm skin. This failsafe is poorly implemented because it can do this while on the ground. If it had in its code that there was no throttle input for 10 seconds and then not implement failsafe regadless of loss of reception, then it might be safer.*** So, just land and turn TI off if you want to, or if you have the board that allows you to adjust TI sensitivity using channel 6 (usually the flap control on a non-Draganfly trademarked TX), then you can adjust the sensitivity to a non-oscillating level. Even with the DFV TI boards there a a few different versions. Does your DF have the channel 6 knob/ability to adjust the TI sensitivity? Are you using the orginal brushed motors and props?
Cheers,
Jim

ericlawrence

Hello Jim: I have a Futaba T6EXAP with my newer VTi and a Hitec Eclipse 7 on my earlier VTi. I have started to experiment with the sensivitity to eliminate the wobble after reading about trees and walls. I have the original brushed motors with heat sinks installed and black plastic props. I have a brace kit I was considering installing (will it make that much difference?). I am very careful in ensuring my birds are last to go on and first to turn off after learning the hard way. You can imagine a newbie watching his bird flip at full throttle (also very dangerous with my T-rex machines). Fortunately, I had a .91 wire roll cage over the DF board. Alas, my newer DF board is not getting a consistent signal. I have an authorization to send it in for repair under warranty. I eventually want to go brushless although the modification looks a bit daunting. I have two earlier boards Spectrolutions will swap for newer brushless boards for less than the going rate for a board replacement. The benefits look to be well worth it and I believe I am nearing the point where I can make the modification. I am also going to order the newer stiffer props I have been reading about. Regrettably, more wind this day which takes the fun out of flying my DF. Therefore, I am working on my T-rex 450's (both eCCPM and mCCPM). The setup is giving me fits despite my best efforts with calipers etc. Since I have six months on Real Flight 3.5 with great success, I am confident once I get the mechanicals down, I will be flying high. Fortunately, forums have proven to be a valuable resource since I do not have access to fly clubs - - Eric

jesolins

Eric,
If you are a Trex pilot, then this Quad stuff should be easy for you I have some Blade CP's gathering dust because they wer too hard for me to fly a year ago. I had to fall back on coaxials and the when I got into quads, then I got hooked. FMS has helped me allot. I would have broken allot of helis and quads if it weren't for that sim. If you do go brushless, here is a mod for the mounts that is working well for me on the standard DF frame. See attached photos. The original mounts that were adapted for brushless just don't hold up well. I guess the BL power is too much for them to handle What boards are you trading in? I heard that Mike Dammer was offering $100 discount on a DFVTI trade-in for the experimental BL board. If the board is newe and has 12 holes pre-drilled in the front, he will mod those for $55. I had the mod done on one of those and then bought a new one. I have two others that are modded using Old man Mike's great opti-mod. The work well too.
Cheers,
Jiim

ericlawrence

Jim: I can appreciate your difficulty with the Blade CP. I have spent months learning single rotor setups. Flight simulators are programmed with the correct setup. Hence, the difference between simulator flying and actual flying generally involves the setup. Regarding simulators, I filed down the spurs on my simulator radio so it now has a smooth throttle. This is my complaint with the two radios that came with my DF's. They both display spurs on the throttle arm (airplane style), unlike my DX7 radio used with my T-rex machines. I might take a chance and modify my DF radios. I would prefer to find a way to use my DX7 with my DF's. Regarding my 2 extra boards, one is an earlier HMX/4 board (my first kit) that I would like t o exchange for a brushless board. I am uploading three pictures of the second DF board. I fail to see the 12 pre-drilled holes in the front and there is no TI. I like your motor modification. Is it possible to purchase an X-pro frame and use it with the DF brushless board? I also have a newly released UFO#4 from Walkera. It flys but hovering is impossible because the throttle curve it too high on the board and I see no way to modify it - - Eric

ericlawrence

Jim: I am uploading some photos of motor mounts I fashioned from my older HMX/4 quadrocopter. They can be made out of plastic or aluminum for brushless. I see that Mike as an X-pro flyer listed on his page with folding arms. Very nice. How does one get the frame? I was considering making a brushless frame out of T-rex carbon fiber tail booms. They are light and strong and can be notched at one end for insertion of a motor mount. I am having difficulty finding connecting tube fittings. I really like the brushless configuration and will soon be devoting more time to building one.

Alas, another windy day so no outdoor flying for me - - Eric

jesolins

Eric,
There are many creative self-build frames. You can get CF rod and tubing from www.Unitedhobbies.com. I would certainly take apart the DF TX and simply put some heat shrink over the lever's pressure arm and also bend it out a bit to loosen it. That will get rid of the rachet action for easier heli/quad flyng, and it is reversible. Do a search in the rcgroups forum for Mikrokopter, UVAP, X-UFO. That Walkera board looked promising for an opti-mod BL too. The folks over in the Walkera UFO forum at rcgroups seem to like it. It certainly hovers in the video... Maybe setting a dual rate of 50% and/or -50 exponential would help with hovering?
Cheers,
Jim

ericlawrence

Thank's Jim: I will modify my TX accordingly. I visited Unitedhobbies. I was impressed with the selection; particularly counter rotating brushless motors. I also found the link to the Walkera TX and will try adjusting the curves according to the instructions and see how the UFO flies. I have quite a lot to read - - so many threads. By the way, I found the problem with my newer DF board - - a fractured wire going to the red LED which was causing intermittent glitching. I used a micro soldering iron with a needle point (the first time I have used it) and soldered the leg. It now works perfectly. I find miniature electronics intimidating. Nevertheless, I am having fun. Thanks again for the valuable information - - Eric

jesolins

Eric,
With these old eyes of mine, and the tiny smd components, I've had to get quite a collection of magnifying lenses. Headmounted, lampmounted, jewlers eypieces, etc. Just part of the fun!...
Not sure what you mean by "counter-rotating brushless motors"? Some BL ESC can be programmed to change rotation direction, but you can alwys just simply reverse two of the three wires going from the EXC to the motor. What there is not allot of are counter-rotating props for different size motors. Beside the DF props, the Maxpro EPP1045's and 12" APC props and some 3-blade ones are about it.
Post a photo of your repair. Am curious as to why an LED connection would cause glitches?
Cheers,
Jim

ericlawrence

Jim: Apparently I will have to acquire a larger magnifying lamp. I am uploading a photo of the repair (it looked pretty good at a distance). After reading some of the threads, I can see I know absolutely nothing about electronics. I did invent a new ignition system for our tactical backpack cutting system (MAG9000) that is featured in "Wired Magazine" this month. Although we are proud of the article, it is small potatos compared to this level of technology. Perhaps you might consider recommending a couple of books to help bring me up to speed. I hate being a complete dummy. The last time I used a scope was to test spark plug wires. The counter-rotating brushless motors I was discussing involves two motors stacked in order to drive two airplane props - - much like a coaxial helicopter that employs two motors side by side. I believe I have seen a similar configuration on a quadrocopter capable of lifting fifty pounds or more. With exception of prop wash concerns, I wonder if it might be employed (with prop modification) on a coaxial?

More wind this day. Drat. I may have to wait until summer to fly - - Eric

ericlawrence

Picture of the counter rotating brushless - - Eric

ericlawrence

Hello Jim:

Wanted to let you know I finally had a chance to fly the new DF with the solder repair using your calibration sequence. It flies like a dream. The steady flight lasted almost twenty minutes using a stock battery and the stock brushed motors fitted with heat sinks. Amazing. Wish my Trex's flew like that. I will soon be taking aerial video now that I have confirmed the reliability of the thermal intelligence. It flew quite well despite a head wind which is so common here in the mountains.

My other VTi (I bought it used on Ebay several months ago) was sent in for repair. It displays the wobble of death despite all of my adjustments and your helpful recommendations. I now see I was working way too hard to compensate for a faulty board. Fortunately, in comparing the two DF's, I realized the wobble could not be completely attributed to pilot error .

I have ordered two additional boards this day; one as a backup for my brushed DF's; the other the newer "brushless" board for experimentation which I am keen to try. Thanks again for the help. I can now see why so many pilots are extolling the virtues of this technology.

One clarification please: Once I have the DF trimmed in TI mode, you stated I should land and pull the throttle down and to the left while pressing the arming button. I presume I do this without first shutting the DF off. Simply put, will the settings be locked in without first shutting the bird down? Thanks again - - Eric

jesolins

Yes Eric. That procedure sets the failsafe trims and will cause the DF to start yawing to the left if the rx signal is lost, which hopefully it never will. The one problem with this failsafe feature is if you accidently turn off your TX while the DF is armd, it will shoot up like a rocket and then start descending. It thinks it is still in the air when you do that. Not a good implementantion. As the manual says, do not test it. It is a poorly implemented falisafe...that makes ground ops potentially unsafe...
Cheers,
Jim

Innerbreed

Interesting thread!

well i may as well add to the unfortunate problems that are happening.

well first ill start by saying i was fortunate to not completely damage mine. i only broke one of the risers!
it was a clear day, but not too hot! i was in a nicely cut, green field, no wind and wearing non high static cloths. (no preference to colour here)

well i started off with normal start up, with TI active and a FULL battery in TX and DF.
after a gentle hover for about 15-20 seconds i ascended about 10ft while in a forward direction.
I must have travelled about 100ft away from me still at 10ft up.

When…
… it fell from the sky!

It flipped over to the left, very fast!
It didn’t seem to throttle up on the right side to course the flip but it was as if the left rotor just stopped.
After inspecting the rig I checked the whole thing over and found nothing wrong apart from the broken riser from the crash.

The motors were find and magnets hadn’t slipped and non solder was cracked.

I didn’t fly it into a shadow or over water or anything that could confuse the TI

I have flown it higher and further since and its been fine.

Maybe TI could have faulted, or it’s a design fault!
(I KNOW WERE I WOULD PUT MY MONEY)

jesolins

Sorry about your crash....what was your TI sensitivity set to? Does your board have the Berg receiver, or the earlier one that is built on the riser board? I'm guessing your motors are brushed? How old are they, not that it couldn't be a faulty new brushed motor. See above posts for more info on this.
Cheers,
Jim

va3mw

I'm pretty new to the DF front, but just received my TI-V a few weeks back. Like old man mike, I've been a Ham for a very long time and clearly understand RF issues.

On the weekend, I was practicing hovering at our cottage which is pretty much in the middle of no-where. I was at about 10 feet with TI turned on and got the quick loss of power which only lasted about a 0.2 of a second. There is NOTHING around that could have caused the loss of signal. I've also had this happen on both the GWS transmitter and the Futaba 6EXP. There is no cold solder joint or crack on the diode that is mentioned in this thread.

I talked to DFI this morning, and they claimed it could be an issue with a cold solder joint with the diode. I can buy this as on my first hard landing, the power lead fell right out of the main board and I had to resolder it. Not good.

That leaves the receiver or main board.

I also keep flying both with and without the cross braces. If I crash with the x-braces on, I seem to have more damage than without. Since the braces stiffen it so much, it transfers the crash energy to the risers and they break. If I don't have them installed, then it seems like the rotor arms take all the energy of the crash and seem to survive much better.

BTW, if your looking for a really light movie camera, try the Helmet Hero http://www.goprocamera.com/index4.htm. We use these for skiing and a number of other ideas. They are pretty light even in the waterproof housing. It even has a photo every 5 seconds mode (3 megapixel photos). Once I feel confident enough to hook it up to the TI-V, I will and will post the video.

Mike VA3MW

www.walkerphotography.ca

jesolins

Another thing to check for glitch causes is the power swich on the board. This is a high failure item. I would suggest turning the board over and soldering a piece of wire between the middle and inner switch pins to short it on permanently. For more DF mod info including the new Experimental brushless board go here: http://www.rcgroups.com/forums/showthread.php?t=768115
Cheers,
Jim

chuck-e

I was getting serious glitching on my dfvti w/ brushed motors.I've been flying this thing for over 2 years and its allways been there waiting to strike.I've tried all the suggestions to fix it and have been unsuccessful until now.What worked for me was cutting down props to 11 inches.It now flys smoother,motors are cooler to touch and climbout is at least as good as with stock length blades.Also, and this is the good part-there have been NO cutouts since.Its been 3 months without a glitch on a board that previously would cut out in mid flight unpredictably.Perhaps reducing load on motors has some effect.

konewone