450 Quadcopter Frame From PolyFlex Pressure Pipe

[kpixels]

No sir, that is not the case. I have no expectations on anyone but myself. Merely pointing out the significance of tuning and just how much it can effect flights no matter if they are FPV or LOS. If you noticed after a lot of your rolls there was a tendency for the quad to wobble about quite a bit. I am reasonably sure that you are not wiggling the sticks back and forth that many times even when flying LOS at a distance.

Okay I stand corrected. It's amazing how you can tell all of that. I'm not debating the benefits of tuning. So where do we go from here, need a baseline, right?

I will give you an example of a better tuned quad being flown LOS where you will see where ever the quad is put it stays. No back and forth action, no floatyness to compare with your flight so you can see the difference and what to look for. This will help in the design process you are going thru as you will better be able to tell or see what is flying and what is physical as far as the characteristics of your craft.

My opinion is there are things that you're not taking into consideration. I just now got the motors calibrated in CF. What you are pointing out could also have something to do with a CG issue because the camera boom hanging off the front. If I showed you the maiden flight footage, you would have to assume that I improved something. It was so bad "all over the place" that I was embarrassed to share it with y'all, sorry.

First thing I changed was to shorten the camera boom which gave great improvement compared to the maiden flight. The thing acts like a lever but I can usually counter it with the battery. In the last video which is snips of all three flights that day, not in any order, I tested it with different batteries, 2200 mah (~180g) and 2800 mah (~225g) and struggled in the field with locking battery at perfect CG, but I can tell you it was probably off.

In the video you can see over corrections, wobbly sticks and uncoordinated turning but you wont see the all over the place reaction after a maneuver. That is what a better tighter tune gets you. That way you are flying your quad not reacting to it if that makes sense. This will also make design issues be more visible then pilot skills or gear related capabilities.

Well if you're trying to say I might not suck as bad as I think, thanks. My plan was, as soon as I get version 2 flying good, then I'll try to flash BetaFlight on this version 1. I'm not holding my breath that it will go smoothly, I've read where some people have lost their OSD after flashing this FC. If I have the slightest problem flashing I will just install a better FC, which I have. Or we can just start tuning in CF now that the motors are calibrated. I appreciate your input,
Ken

 

[PsyBorg]

You will be surprised how much CG does not matter so much on a quad. Thats where tuning comes in as you can make one axis tighter then the others to compensate for a lot of imbalance. ( I am by no means saying put all your weights on one end of the quad) Push your P gains on pitch and roll up a few (tenths for CF I believe) points and you will see the difference that makes as the looseness wanes a bit. That's the nice thing about flight controllers you can play around all you like to see what does what and then set it right back to the beginning unlike fixed wings and moving weight around to find the balance.

 

[LitterBug]

kpixels,
There is another route you can take with tuning, and that is to use a firmware that has autotune. I'll have to look at what FCs you have to see if any are capable of running dRonin, but I run it almost exclusively because it is capable of generating it's own tune specific to your vehicle with just a 1 minute flight. It wiggles it aournd each axis and measures the response time, then based on that adjusts the PIDs. Sample graphs it shows from data collected below:




FYI, the F550 Hex in the video I posted earlier is running it on a DTFc flight controller.

Cheers!
LitterBug

EDIT: looks like this one might be a good candidate to try, as long as it doesn't have an SD card reader built in: Wolfwhoop Omnibus F4 Flight Controller with PDB, VTX and OSD ($43)

 

[kpixels]

You will be surprised how much CG does not matter so much on a quad. Thats where tuning comes in as you can make one axis tighter then the others to compensate for a lot of imbalance. ( I am by no means saying put all your weights on one end of the quad) Push your P gains on pitch and roll up a few (tenths for CF I believe) points and you will see the difference that makes as the looseness wanes a bit. That's the nice thing about flight controllers you can play around all you like to see what does what and then set it right back to the beginning unlike fixed wings and moving weight around to find the balance.

Thanks PsyBorg, I'm going to try to hit the field tomorrow and will probably do a quick flight before I change PIDs and see if calibrating the motors changed anything for better. Was thinking about taking my laptop to change PIDs in the field but then it just dawned on me, I think I can change them with my TX using the OSD. Either way I'm really interested in seeing what those changes can do. To be continued...

 

[kpixels]

There is another route you can take with tuning, and that is to use a firmware that has autotune. I'll have to look at what FCs you have to see if any are capable of running dRonin, but I run it almost exclusively because it is capable of generating it's own tune specific to your vehicle with just a 1 minute flight. It wiggles it aournd each axis and measures the response time, then based on that adjusts the PIDs. Sample graphs it shows from data collected below:

Yes, I'm familiar because I used to do that all the time with my Naze32 Acro boards. Can't remember which configurator I was using, maybe BaseFlight. It's hard to forget because I had to give up one of my aux channels to use it. I was trying to step up from the F3 boards because they seem to be getting cramped, outdated and I was having more and more issues when I would try to build something new, especially tricopters. I didn't even notice AutoTune missing. My favorite before was the Naze32 Acro 10DOF.

FYI, the F550 Hex in the video I posted earlier is running it on a DTFc flight controller.
EDIT: looks like this one might be a good candidate to try, as long as it doesn't have an SD card reader built in: Wolfwhoop Omnibus F4 Flight Controller with PDB, VTX and OSD ($43)

Yes that hex looked pretty smooth, I meant to mention that before. I like that the DTFc has the PDB built in. I will probably pick one up to try if you recommend it. I have this "FORTINI F4 OSD 32Khz Flight Controller" in my shopping cart for a five inch. I was looking at the Strix frame you mentioned and I'm really interested that frame. I didn't realize you had built those already but I came across one of your videos.

Back to AutoTune though, I have the Wolfwhoop you mentioned but it does have an SD reader. I thought that would be an asset, hey look 32GB drive up there. It's actually for blackbox which should be pretty cool (to tune PIDs). I have a RipaFire F4 (with BetaFlight) but it has SD slot also. Then I have an F3 Naze32 full which has BaseFlight on it. I checked them all and didn't find AutoTune but they do have "inflight_acc_cal".

One of these needs to go on the new tricopter and that's how that Illuminati ended up on the quad. Out of the RipaFire F4 and the Naze32 F3, which would be better for tricopter? Thanks for the input I really appreciate it...
Ken

 

[kpixels]

Wow, looks pretty bomb-proof! I always thought H-quads just looked cool. Do you think you could drill some holes in the pipes to make them lighter, or would that have negative effects of vibration and stuff?

Hi PenguinWings, Decided to try drilling just the T fittings to see how much weight could be shaved without compromising too much strength. In hindsight I should have kept the holes where they will be covered by the poly pipe. This is only for Version 1. Just these 20 holes (~ 1/4") shaved off almost 10 grams. By drilling all the way thru that was only 10 drill presses. With a combination of these and some smaller holes you could probably shave 40 grams off both Ts.
That's pretty good, thanks!
Ken

 

[kpixels]

Good News Bad Day

Version 2 is 100% fixed as far as the unstable oscillation (torsional vibration mode, Galloping Gertie) that made it unable to fly other than hoovering. By reinforcing the center span, it added about 60 grams but is very rigid from front to back now. It's a temporary mod just to see if that was the problem but I have a permanent mod solution for this one and a change to the design.



Unfortunately it was dreary all day. I did fly version 2 under a shelter house and burnt up a whole battery. It seems to have the same boaty feeling (at times) as version 1, it was nose heavy though. I need to add an additional battery strap so I can move it back further. I didn't fly version 1 at all, to try new PIDS. Will try to fly them both tomorrow if the field isn't too flooded.

Thanks everyone,

 

[kpixels]

Shake, Rattle And Roll: JELLO Anyone?

VOLUME ALERT! This is the version 2 poly quadcopter, once over and first flight in horizon mode (3rd full flight). I know it's horrible footage! Winds were 15mph+ form the west (direction of sun in video) and you can probably tell I don't have a lot of experience in horizon mode. It felt OK except for the bounce which hopefully will be corrected by tuning PIDs. (YouTube)

 

[kpixels]

Well version 2 flew without crashing, it didn't look pretty though. It feels about the same as version1 which needs tuned badly, except towards the end of this flight it felt a lot worse. I'm not sure if it's because of the 15mph wind and/or that I forgot I was still in horizon mode when landing. Nothing changed physically with the copter that I could tell, but I didn't feel comfortable catching it. I had placed the battery further back than previous flights. I'm trying to get the CG close to the center of the flight controller but it seems happier (less bouncy) being nose heavy. PIDs I know, it was too soggy to drag my laptop to the field and I couldn't recall how to get into the setup thru the OSD. Next field trip will be nothing but tuning PIDs I promise.

PsyBorg, LitterBug, where should I routinely set the CG/place battery for these quads before I tune the PIDs?

 

[LitterBug]

kpixels,
Glad you were able to get some stick time in over the weekend. I managed to get some indoor time in friday night, but nothing outdoors. Busy helping my parents out yesterday so didn't get out. Looks like the next three days will be ideal for our area. At least temp and dryness wise. Haven't looked at wind reports yet. I won't get out tonight since I need to swing by my parents again, and also go to a funeral for a slightly younger friend of mine that passed last week from the flu. :-(

Getting back to your tricopter question, I've played around and flown four different tricopter builds. Most have been on the RCExplorer F3FC racing FC. Currently have my RCE Mini Tricopter running on a DTFc and am rebuilding a hugemongous Hobbyking Y-3 with a DTFc as well. I would stick to something that is supported by TriFlight with an available ADC pin (rssi) for servo feedback. I am running a branch of dRonin that has the triflight tail routines added in, for the benefit of autotune plus the better yaw control. I did autotunes on my MiniTri and a BabyTri friday night indoors. My buddy who didn't know what changes I was making noticed and even commented on how well the mini-tri looked after I enabled the Tri routines. I still need to get LEDs on the tris for orientation. I have a real hard time flying them LOS compared to a quad because of orientation confusion...

Cheers!
LitterBug

EDIT: CG wise, I "try" to keep as close to center on all axis as possible, or maybe slightly forward. That will keep all motors working evenly and give more consistent handling. The FC can make up for quite a bit, but at some point, it can get unstable and more difficult to tune, especially if you are running on the ragged edge.

 

[kpixels]

CG wise, I "try" to keep as close to center on all axis as possible, or maybe slightly forward. That will keep all motors working evenly and give more consistent handling. The FC can make up for quite a bit, but at some point, it can get unstable and more difficult to tune, especially if you are running on the ragged edge.

Hi LitterBug, Thanks for that info. I flew them both tonight and version 2 flew a heck of a lot smoother with no wind and with the battery moved forward. I just figured out what's throwing me off with the CG. The flight controller is mounted at the center of front and back motors, but that's not the center of mass because of the camera. I've been putting the battery back too far, it wasn't nose heavy at all. Can't wait to try the correct CG point. Thanks,
Ken

 

[kpixels]

Getting back to your tricopter question, I've played around and flown four different tricopter builds. Most have been on the RCExplorer F3FC racing FC. Currently have my RCE Mini Tricopter running on a DTFc and am rebuilding a hugemongous Hobbyking Y-3 with a DTFc as well. I would stick to something that is supported by TriFlight with an available ADC pin (rssi) for servo feedback. I am running a branch of dRonin that has the triflight tail routines added in, for the benefit of autotune plus the better yaw control. I did autotunes on my MiniTri and a BabyTri friday night indoors. My buddy who didn't know what changes I was making noticed and even commented on how well the mini-tri looked after I enabled the Tri routines. I still need to get LEDs on the tris for orientation. I have a real hard time flying them LOS compared to a quad because of orientation confusion...

Well sounds like a crash course on DTFc and dRonin. Where do you recommend buying the DTFc? I'm sorry to hear about your friend.
Ken

 

[LitterBug]

I bough a bunch of DTFc FCs from RMRC on clearance last fall, but they don't sell them any more. You can still get them from GetFPV.com or direct from airdtf.com. For the sake of tricopter support, you are probably better off going with David Windestål's F3FC Racing FC and Baby PDB. https://rcexplorer.se/product/f3fc-racing/ and https://rcexplorer.se/product/babypdb/ . Will be slightly cheaper for the combination as well. I have three sets of these and have had 0 issues. The I2C bus is readily available for adding a baro/compass/etc, 3.3v for spektrum is broken out, Servo feedback pin is readily available, the pdb has selectable voltage for HV servos, etc. If you want to get up to speed on dRonin, it can be found at dRonin.org. There is native support for tricopters, but there is also a development branch that one of the Developers has that integrates the tail routines from TriFlight which flies even better. TriFlight is a fork/branch of BetaFlight which adds additional routines that add better yaw control. I should do a video compariing different flight characteristics. It's a pretty obvious difference with the "TriFlight" routines enabled vs. stock firmware.

Thought about hitting the field last night, but fired up the grill instead... Was SOOOOooo nice out last night. Was playing around with the DJI F550 hex in the back yard while grilling. Threw the latest dRonin firmware on, bumped it up from 3S to 4S, did a fresh autotune, and it was an absolute HOOT doing punchouts. Motors did not even get warm. Think I may tempt fate and bump it up to 6S for some really crazy fun.

Cheers!
LitterBug

EDIT: FYI you can see some of my latest tricopter shennanigans over here http://forum.flitetest.com/showthread.php?35836-RCExplorer-Mini-Tricopter-Build-thread

 

[kpixels]

I bough a bunch of DTFc FCs from RMRC on clearance last fall, but they don't sell them any more. You can still get them from GetFPV.com or direct from airdtf.com. For the sake of tricopter support, you are probably better off going with David Windestål's F3FC Racing FC and Baby PDB. https://rcexplorer.se/product/f3fc-racing/ and https://rcexplorer.se/product/babypdb/ . Will be slightly cheaper for the combination as well. I have three sets of these and have had 0 issues. The I2C bus is readily available for adding a baro/compass/etc, 3.3v for spektrum is broken out, Servo feedback pin is readily available, the pdb has selectable voltage for HV servos, etc. If you want to get up to speed on dRonin, it can be found at dRonin.org. There is native support for tricopters, but there is also a development branch that one of the Developers has that integrates the tail routines from TriFlight which flies even better. TriFlight is a fork/branch of BetaFlight which adds additional routines that add better yaw control. I should do a video compariing different flight characteristics. It's a pretty obvious difference with the "TriFlight" routines enabled vs. stock firmware.

Thanks for taking the time to share all this. I found this DTFc for $25 and went ahead and snagged it yesterday;
DTFc Flight Controller F3 6S Capable By DTF UHF dtfc
I found it at quadquestions.com out of Denver. They seemed legit, I hope it will work for dRonin. Will still be cool to check out either way. Does the "D" by chance stand for cute little Doge? Just curious, saw something about OSDoge.

Thought about hitting the field last night, but fired up the grill instead... Was SOOOOooo nice out last night. Was playing around with the DJI F550 hex in the back yard while grilling. Threw the latest dRonin firmware on, bumped it up from 3S to 4S, did a fresh autotune, and it was an absolute HOOT doing punchouts. Motors did not even get warm. Think I may tempt fate and bump it up to 6S for some really crazy fun.

That sounds like a hoot! Does it even have a paload, or are you just going for extreme overpower, ha ha?

EDIT: FYI you can see some of my latest tricopter shennanigans over here http://forum.flitetest.com/showthread.php?35836-RCExplorer-Mini-Tricopter-Build-thread

Heading there now, thanks,
Ken

 

[kpixels]

You will be surprised how much CG does not matter so much on a quad. Thats where tuning comes in as you can make one axis tighter then the others to compensate for a lot of imbalance. ( I am by no means saying put all your weights on one end of the quad) Push your P gains on pitch and roll up a few (tenths for CF I believe) points and you will see the difference that makes as the looseness wanes a bit. That's the nice thing about flight controllers you can play around all you like to see what does what and then set it right back to the beginning unlike fixed wings and moving weight around to find the balance.

Hi PsyBorg, Good call on the PIDs! I ended up having to go forward with the battery to balance the correct CG point. Like you said, CG would not matter so much, it didn't, the bounce was still there. This was version 2 and in BetaFlight, I increased the P by 10, increased the I by 5 and I left the D alone but increased TPA from .10 to .25. From what I've seen so far, I can't wait to try them at the field. Pretty sure version 1 is going to be the same deal. Thanks,
Ken

 

[LitterBug]

Ken,
The F550 is a bare minimum build, but still a porker at 1200g. Frame: DJI F550, motors, props, 30A 6S escs, battery, RX, and DTFc FC(6S). 4S is probably safe. Run the risk of exploding the T-Motor carbon 9x3x2 props if I do full punch outs on 6S as RPMs are probably well beyond the design specs from many many moons ago when 3S 980kv was the expected operating environment. Won't stop me from doing it for shiggles once or twice out at the field where there is less likely to be damage other than to the hex.

DTFc will indeed run dRonin natively and is also a target for most *flight based firmware. AirDTF did indeed do a bunch of stuff with "Doge" branding. I had no idea what Doge was until chatting with Englishman (Runs AirDTF) recently on the dRonin IRC channel. Asked him if that was his dog on the OSD Doge, and DTFc packaging and was enlightened on where that all came from. Somehow I missed out on this big internet meme a few years back.http://knowyourmeme.com/memes/doge LOL

Such WOW!

Cheers!
LitterBug

 

[LitterBug]

Ken,
I also have a couple of the DTFcs with FrSky R-XSR RXes set up to use in planes. Gives me power monitoring, telemetry, 6channels , and the possibility for stabilization in a easy plug package....




Cheers!
LB

 

[kpixels]

DTFc will indeed run dRonin natively and is also a target for most *flight based firmware. AirDTF did indeed do a bunch of stuff with "Doge" branding. I had no idea what Doge was until chatting with Englishman (Runs AirDTF) recently on the dRonin IRC channel. Asked him if that was his dog on the OSD Doge, and DTFc packaging and was enlightened on where that all came from. Somehow I missed out on this big internet meme a few years back.http://knowyourmeme.com/memes/doge LOL

Such WOW!

Hi LitterBug, WOW, can't stop laughing! As much as I have always loved Doge, I missed that animation. Put me in a great mood, thanks! It's amazing how he turns up everywhere. His cute mugshot is definitely going somewhere prominent on this tricopter now!

Well, so I want to build a 5 inch around around this FC. I have some parts in mind like Mr. Steele motors, but I'm not sure if those are best and can't decide rest of the parts. I'm only interested in freestyle, totally open to suggestions;

 

[LitterBug]

I've been flying mostly Edge Racing Light 2205 2480kv on my 5" freestyle quads and one of my baby tricopters. They are Smooth and light. Starting to play around more with T-Motors lately too. I really don't like the uber notchy over magneted motors that a lot of racers prefer. The Steel motors are supposed to be smooth, but I'm not a big fan of his. Recently went with some Tmotor instead on a Strix Screech build. Wanted low 1600kv 6S motors for this build. Playing with 6s not for uber high wattage and power, but for all around efficiency. High Voltage at low current for same wattage = less thermal loss. Also should equate to less sag. Run mostly 30A ESCs on my 5" and up quads.

Cheers!
LitterBug

 

[kpixels]

Tree Smacks Down Poly Quadcopter After 1st PIDs Tune

Gets right back up for more though! Can probably tell from footage I chipped the tips off one of the propellers. First test flight in open area after tuning version2 PIDs in BetaFlight on Omnibus F4 flight controller. Still has a ways to go but it is improved. Learning as I go about what these adjustments are actually doing. Next flight I will be further tuning in the field where I can get on it, just haven't had time or nice weather. Also the vibration blurring and jello are from a reinforcement mod and will be fixed soon. (YouTube)