Twitchity Hex - Oh boy, here we go again!

jhitesma

Some guy in the desert
Mentor
jhitesma crash videos are the best crash videos

Don't get too excited. These were pretty dull crashes tonight ;)

The quad fails is up and processing on youtube. You'd think I'd have learned my lesson about those spec sat wires by now...I'd say more but it would give away the surprise ;)
 

narcolepticltd

I unbuild stuff regularly
Don't get too excited. These were pretty dull crashes tonight ;)

The quad fails is up and processing on youtube. You'd think I'd have learned my lesson about those spec sat wires by now...I'd say more but it would give away the surprise ;)

I'll be watching intently... I like learning from other's mistakes ;)
 

cranialrectosis

Faster than a speeding face plant!
Mentor
Some nice flips and rolls there jhitesma!

I find the hex is absolutely elegant in the air. Those barrel rolls are beautiful to watch, particularly when you have forward momentum. I like how this copter cuts through the air too. It has enough ballast to handle some moderate breezes and enough power to fly against some wind.

I have had mine out at the new field once now. I got it up to <> 75% throttle doing flips and rolls before I chickened out on the speed. I'll get the Mobius out this weekend when I go to the new field.

That Brain with TAU on it seems to handle pretty well. I find the hex to be wide enough that it has some natural stability in rate mode. That with the ballast, makes it pretty easy to park the copter in one place or catch the copter coming out of a flip, spin or roll.

My only real concern now is battery life. My 1300mAh 45-90C lipos don't last long and my 2200mAh 45-90 lipos are almost 3 years old and start to sag (on any of my copters) at about the 5 minute mark. My 1800mAh at 35 C is woefully underpowered (Mustang triggered a voltage alarm Sunday in under a minute of flight). I am thinking of getting some nice 65C 2200s so I can really crank it.

I'm glad you flipped it, jhitesma. I think your FPV experience will be better for it. I hope this copter helps you explore some canyons in style. :)
 

jhitesma

Some guy in the desert
Mentor
Some nice flips and rolls there jhitesma!

So that's where my first view came from :)

For everyone who isn't following my youtube feed:


I really, wasn't really trying to show off or anything with it yet - just feeling out it's envelope and how it responds to various things at this point. When I got there I had the whole park to myself. But in the evening the light is horrible flying from the parking lot. So I had to walk way out into the field to try and get better light. I was almost at the far end when I did the first flight - then I broke that prop. While I was replacing the prop some people with dogs showed up. And while it's an on-leash only park I'm still nervous flying near dogs. So I cut my flying window in half. So by the time I really got going on flips I was in a smaller area :(

Then two people showed up to play Frisbee golf. So my flying area got even smaller. That was when I pulled out the quad. Which didn't go well:


That first crash was because it was responding REALLY odd in the air and heading towards the golfers - so I decided to just ditch it ASAP. Looked fine when I picked it up, but then armed the motors and half a prop flew off. Replaced the prop and then it wasn't responding to my TX. Took a closer look. The power wire to the RX had come loose. Even after I promised to put a drop of hot glue (I say epoxy in the vid but meant hot glue) on those last time this happened (at this same park.) So I've got a small wiring repair to make again.

Went to fly the hex again...and while I was getting it prepped my TX started beeping at me about a low battery. I just charged it 3 weeks ago and haven't flown much at all. It's also getting puffy. It's a LiFe and has been treated well and in turn treated me well. But right when I got it I had a small accident with a charging harness and as a result it's had one cell that never really balances well. Probably time to pickup a new battery.

I find the hex is absolutely elegant in the air. Those barrel rolls are beautiful to watch, particularly when you have forward momentum. I like how this copter cuts through the air too. It has enough ballast to handle some moderate breezes and enough power to fly against some wind.

Fully agreed. That first reverse barrel roll really caught my attention. But I just didn't have enough space to really feel safe doing many moves with momentum. I don't know how well it comes across in the audio but you can probably hear the wind blowing, it was a good 15mph with some decent gusts on top and the hex handled it great. That was what happened when I went to land in the truckbed. Not only had I not left enough room but a gust came up and spooked me so I aborted and did a ground landing instead ;) Definitely handles wind better than anything else I have though.

I have had mine out at the new field once now. I got it up to <> 75% throttle doing flips and rolls before I chickened out on the speed. I'll get the Mobius out this weekend when I go to the new field.

That one punchout was at about 75%. The problem I'm having is even when I try to give it full throttle I can't bring myself to just slam the stick - and it takes it a moment to "spool up" and start responding to the stick...then suddenly once it does it just takes off. It doesn't have the instant response that a quad does - but when it gets going it GETS GOING. It's more like driving a truck than a sports car - but still driving it like it's a sports car ;)

That Brain with TAU on it seems to handle pretty well. I find the hex to be wide enough that it has some natural stability in rate mode. That with the ballast, makes it pretty easy to park the copter in one place or catch the copter coming out of a flip, spin or roll.

I really can't get over how locked in it feels just with the autotune. I have seldom had my MW (8 or 32 bit variants) setups this locked in - and it always took weeks of tweaking to get there. There is definitely a lot more natural stability than mini quads, and there's more than my similarly sized knuckle quad. This is actually slightly larger than my knuckle (and my knuckle is actually slightly larger than stock as I sized it for future experiments with 10" props.) The combination of extra size and 2 extra motors really makes it stable. You may notice in the videos that I actually look down at my TX a little even when flying in rate. I don't do that with any of my other multis as none of them feel stable enough for me to feel safe glancing away.

It does roll great, but I'm still only at 400 deg/s on my rate. If I get that up a bit higher it will to tighter quicker flips, but as you probably saw in the video with careful throttle modulation it can do some very precise flips already. The 35% expo I added in did help smooth it out without removing that edge - I can see it will be nice for FPV. But for LOS I preferred no expo even if it looked a little "sharp" in the sky.

My only real concern now is battery life. My 1300mAh 45-90C lipos don't last long and my 2200mAh 45-90 lipos are almost 3 years old and start to sag (on any of my copters) at about the 5 minute mark. My 1800mAh at 35 C is woefully underpowered (Mustang triggered a voltage alarm Sunday in under a minute of flight). I am thinking of getting some nice 65C 2200s so I can really crank it.

Both of the flights that made up that video were on the same Zippy 40C 2200 on one charge. The pack was reading 7.8v on each cell after resting a few minutes. Motors and ESC's were cool to the touch. Recharging the pack it sucked up 1400mah. That was pretty low throttle flying though. Still it looks like I should be able to easily get gentle 7-8 minute flights off my good 2200's. I doubt spirited flying would go much past 5 minutes - and I doubt I could keep it up for much more than 5 minutes anyway :D

I'm glad you flipped it, jhitesma. I think your FPV experience will be better for it. I hope this copter helps you explore some canyons in style. :)

Well, the FPV experience is going to be a bit delayed due to the flipping.

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Though to be totally honest it wasn't the flips. It was just playing around with little throttle cuts and an accidental brush with the ground.

Need at least a new antenna and probably a new TX now. I was thinking about getting a different one anyway...I'm going to need 1.2/1.3 for where I hope to fly this eventually....
 

jipp

Senior Member
thanks for posting the videos here too. i will be happy when i can fly line of sight as nice as you were before the crash put a stop, the hex looks great in the air. flips nice, reminds me of a spider for some reason.

is it normal to break FPV gear in crash's? or just a one off, right angle type thing. i can afford props but not replacing fpv gear often if i go that direction. but hen i guess the better i get at flying, and once the tuning is done ( i assume, it will be like starting over when i go to a larger quad.. but i bet it takes a few flights to get use to any new air frame.. ).. it would not be that big of a deal to break something that is a little expensive at times. as long as one is having fun.
chris.

ps.

can you explain the different modes. i assume my FC will share the same as tau.. as ill probably stick with OP first before flashing TAU,, so i have a better understanding what im doing.

on the blade nano you have.. self leveling, and hard mode i guess. with low and high rates.

it seems on the tau.open pilot you have, horizon, acro, and ?

chris.
 
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jhitesma

Some guy in the desert
Mentor
thanks for posting the videos here too. i will be happy when i can fly line of sight as nice as you were before the crash put a stop, the hex looks great in the air. flips nice, reminds me of a spider for some reason.

Actually what finally put a stop to the hex flying was my TX battery getting low. I only broke 2 props and that VTX. But I also only got to fly one full pack due to the TX battery going low and the quad having it's issues.

is it normal to break FPV gear in crash's? or just a one off, right angle type thing. i can afford props but not replacing fpv gear often if i go that direction. but hen i guess the better i get at flying, and once the tuning is done ( i assume, it will be like starting over when i go to a larger quad.. but i bet it takes a few flights to get use to any new air frame.. ).. it would not be that big of a deal to break something that is a little expensive at times. as long as one is having fun.
chris.

Depends on how it's mounted and how you crash :) I had it pretty exposed but didn't consider it a permanent mounting location. With the antenna direct mounted like that it's also easier to break things. I pretty much knew that in any crash this TX was going to take damage the way I had it installed. I plan on installing one in a more protected location with some coax to the antenna - but didn't have the right antenna on hand to do that. This is just a $25 TX...still not fun to have to replace but no like breaking a $130 brain board or a $25 motor and $20 ESC ;)

can you explain the different modes. i assume my FC will share the same as tau.. as ill probably stick with OP first before flashing TAU,, so i have a better understanding what im doing.

I don't really know what the modes are on OP - I think they use slightly different names for some of them.

On Tau the main modes are:
Acro - gyros only "rate mode" - your stick inputs determine the rate of change in angle.
Attitude - self-leveling "angle mode" - your stick inputs set the angle desired.
Horizon - around center stick it works like attitude, but further out it works like acro. It's more of a rate mode but with a self leveling component near the center.
MWRate - MW 2.3 style PID controller. Uses different PID's than the native modes.
Vbar - "virtual flybar" designed for helis but works on multis. Tuned through settings in the UAVOBJECTS browser much differently than a normal PID setup. Has an odd feel in the air - really does feel like a FP heli with a flybar.
Altitude - Altitude hold - "vario mode" throttle controls altitude not speed, self-leveling angle style mode.
POS - Position hold - attempts to hold position in 3D space, various settings can be changed to determine whether or not it also tries to do altitude hold and whether or not stick inputs do anything.

There are some others as well like "weak leveling" that I haven't even experimented with.

I tend to mostly fly acro or horizon and tend to prefer acro as long as I have enough space around me in case I loose orientation and have to crash. Horizon I prefer in smaller areas since it's easier to let it self-level and hover.
 

cranialrectosis

Faster than a speeding face plant!
Mentor
I liken flying the hex to driving a Corvette.

It takes a LOT longer to get up to speed than a Ninja 650 and it won't corner like a Miata, but get it on the open highway and it will blow your hair back pretty well.

Tuning is a major league hassle, not just for this hex, but in general IMO. I am fighting some yaw drift and yaw P gain issues. After every yaw turn, the copter wants to shoot 5' into the air. It won't take more than 30 minutes to fix but the wind is doing 25mph outside this week and tuning in the wind is futile.

I crashed my hex Saturday trying to platform land on the picnic table... There is enough downdraft to make the copter floaty above a surface. It is easier to land (or flip) this copter with some lateral momentum. Of course, a good tune helps a ton here too.
 

jhitesma

Some guy in the desert
Mentor
Turns out the VTX still works. Took my spare 4 lobe "RX" antenna and put it on to test.

Haven't had a chance to do a full range test on it yet but at least a quick test to the end of the block still looked rock solid. (That's a quick test with the multi sitting on the tailgate of my truck in the driveway and me walking down the street with the goggles and RX.) Still don't trust this setup long term or for me to pilot through - but have a friend in from out of town who I may get to take for a ride this weekend so I wanted to get a feed working.

But my job is crazy right now so who knows when I'll have time to get out and do any real flying for the next few months :(
 

jipp

Senior Member
be sure to take a little bit of time for your self.. it sucks to work one self into the ground.. a little break from time to time is all that one usually needs to feel alive again.

well i guess the good news the heat is here almost so, not much going on during the day anyhow but hiding by the a/c
chris.
 

jhitesma

Some guy in the desert
Mentor
So decided I wanted to finally test fly my Knuckle with oneshot...but remembered I had to steal the RX from it for the Hex. Don't really want to have to keep swapping it back and forth. And I saw earlier this week that Midelic updated his FlySky code to support RSSI out and was looking for someone to test it. Since I have the Brain board with the built in OSD RSSI would be really nice to have...and since I still have a few more A7105 modules and arduino pro mini's on hand....

11144812_10152691196611805_1097764080_o.jpg

11153608_10152691196766805_1722225579_o.jpg

Didn't bother with a status LED...May wire one in later. Realized that I never bothered with one on my original DIY RX either...what I thought I had wired as a status LED is actually just wired as a power LED...don't remember if I did that on purpose or by mistake. Probably by mistake :D

Anyway, first I flashed the same sketch I used on my existing RX to confirm this one was working....tested out great first try.

Next I flashed the new .hex midelic provided...flashed and works. With my oscilloscope I can see a signal on the RSSI pin (it's setup to output RSSI as a PWM signal on the Ch 6 pin while the RX signals are output as PPM on the Ch 5 pin.

It's also supposed to be outputting serial info for debugging...but for some reason I'm not having any luck with that.

But now I'm a bit stuck. The specs of the Brain board say it supports RSSI as PWM...but I can't figure out how to set it up. I'm wondering if it's only possible when using PWM input as well. Midelic plans on eventually setting the RX up so it will inject RSSI into a PPM channel...but it was quicker to do PWM output for testing first.

Even if I did get it configured and reading RSSI in the OSD I wouldn't be flight testing it yet though as the .hex midelic provided doesn't have failsafe setup in a way that's usable for me. (It sets ch2 [throttle] to min but all the others to 1500 - I setup mine to output 0 when in failsafe.)

So no RSSI for me yet. But at least I do have another working RX with failsafe. Still need to whip up one more (and I still have enough parts to do so) since the emax needs an RX as well.....maybe tomorrow.
 

jhitesma

Some guy in the desert
Mentor
Ahh...what the heck. A status LED would be nice.....

My first pro mini board didn't have the usual D13 LED. But just looked at this one and it does...thought about tweaking the code to use that for the status instead of A3. But saw that D13 is already used for PWM ch 8 and there aren't any other open pins I could easily assign that to (at least none that jumped out at me.) Thought about cutting the trace and hot wiring it to A3 - but the way the board is laid out that would leave D13 unusable.

So instead I decided to lift one side of the resistor driving the LED and hot wire it from there. But when I did so I managed to break the resistor. Whoops. I'm horrible at unsoldering these 0603 parts without killing them.

Thankfully I have some other 0603 resistors on hand from the V1 Twitchity quad PDB. They're a lower resistance but the LED was really dim...I'm over driving it just a tad now but it's actually bright enough to be usable :D

No photos because my phone is on the charger. Will try to remember to get some tomorrow.
 

jhitesma

Some guy in the desert
Mentor
Still haven't finished testing the RSSI out on the new RX...been a bit busy testing Tau on the Naze32 now that I have that working on my emax build.

But...got another little bonus in my check this week so finally ordered up a couple of voltage/current sense boards to wire into this and the emax. Really put that OSD to the test :D

Speaking of which, I had forgotten that I had this little toy:
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A friend of mine had a security company for a number of years. Right after I moved into my house he got a job to refit one of the local casinos video setup. Apparently they had a bank of 20 or 30 of these that were never even powered on before they were replaced. (I guess they were setup as redundant spares or something.) It's fully decked out with the biggest drives it would take and can handle something like 240 hours of video at it's highest quality setting. SD only, but that's all the signal from my FPV gear is anyway.

Of course...it's kind of bulky and 110 only so it's not super practical...but I've got a nice inverter that should be usable to power this bad boy and take it out to record some google eye view of the OSD while flying.

I'm just one BNC->RCA connector short of using it...and I know I have one here somewhere. I brought about 10lbs of RF connectors back with me from my parents house last time I visited them...but can't remember where I put them! Spent almost two hours searching but have had no luck locating them or any of my own RF connectors. I'd go up to radio shack and buy one but they're so overpriced (if they even have one) and I know that as soon as I do I'll find all the connectors I already have ;)

Oh...and note in the background of that photo....my prop order came in. Should be able to have some fun this weekend. Well, Sunday at least. I've got a double birthday party for some of my daughters classmates and a "Fairy Party" I have to take her to tomorrow because my wife is working.

Just need to confirm a spotter....
 
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jhitesma

Some guy in the desert
Mentor
Here's a quick test from the DVR:


Little dim in my backroom so the camera switched to B&W. Also confirmed that my inverter can power it just fine, draws about 30watts on average but has a 50w spike when starting up. But - that means it draws a 2200 down a bit too quick to be usable (It's also a pain to get setup as it's backup battery is dead so it won't work until I hook up a screen and reset the clock each time....then exporting video out of it is really annoying as you have to specify the time range you want.)

But it does work and for free I can't complain. Will give me a way to record video from the flights - I'll just have to run it off a big lead acid battery instead of my lipos. Should give me extra confidence flying FPV with this since I'll have a record of the OSD/GPS if I go down.
 

jipp

Senior Member
very cool.. also with a lead battery you could use it to charge while you are flying.. double bonus.. may as well get the most out of it field charger and fpv recorder.. my grand ma use to always tell me if its free its for me.. heh.

chris.
 

jhitesma

Some guy in the desert
Mentor
I could...but since I only charge at 1c it usually takes an hour to run a charge cycle. So I end up draining all my packs in less time than it would take to re-charge one of them.

A parallel charging board would let me do more than one at a time...but then I'd run into the limits of the charger...and I'm usually not at the field much longer than an hour since that's all the time I can find to get away :(
 

jipp

Senior Member
yeah thats cool.. yeah rule of thumb i was told basically 1300mah 1.3a or so safely.. the charger i bought can charge two at a time with out any fancy setups which is cool.. but it wont run off dc.. so i will need to get one that can just in case down the road.
i guess the ticket here is more battery's! heh.

which will be fine once i get to that point i know what battery's and props to stock up on.

chris.
 

jhitesma

Some guy in the desert
Mentor
Holy cow radio shack. If you charge $9 for a freaking BNC->RCA adapter and are still going bankrupt...you deserve to go out of business!

Could get a 10 pack with free shipping for $3,50 on ebay. But I don't want to wait. I don't mind paying extra for convenience...but let's be reasonable here people!

It probably wouldn't sting nearly as much if I wasn't sure that now that I've paid that much I'll almost certainly find one in the next hour or two....
 

jhitesma

Some guy in the desert
Mentor
Well the hex has had it's FPV maiden. Was dead calm all day but didn't get a chance to fly until evening. Went back out to my favorite desert flying spot "the names" and we brought along some friends and their daughters as well to make a family outing out of it. Unfortunately despite it being dead calm when we left town when we got out there...it was really gusty :(

The hex had no problems fighting the wind (and neither did my Twitchity 230 or my emax 250...but those are off topic in this thread :D ) but the gusty wind made it all but impossible for me to fly even remotely smoothly as I kept getting tossed 2-3 feet in various directions - including up and down :(

So the video is very unimpressive...but here it is in all it's unedited glory (sorry guys, no time to edit today)


And....as an added bonus...this was also a live test of the DVR. Which worked quite well - so here's the live footage as I saw it in my goggles:


Things to note...the altimeter in my OSD seemed all kinds of messed up...I don't have any foam over my baro yet though so I wasn't surprised. Looks like something was up with my GPS as well as it always showed 0m to home. I really haven't setup the OSD much yet though so I'm not surprised that pretty much nothing on it was responding very well other than the artificial horizon.

I got a good 8 minutes of flying and my pack was still above 3.8v per cell at the end...so I wouldn't be surprised if I could get 10 minutes of gentle flying out of 2200's on this hex...better than I expected.

One thing I had on my minim OSD that I wish the brain had is a flight log at the end when you disarm showing thigns like top speed, furthest distance and length of flight. May have to look into that...

After that one flight I decided not to try any other as it was just too windy to be fun. Did some acro flying with the 230 and 250 - set the 230 into angle mode turned up my expo and dropped the rates and let my friend give it a try. Think he may be hooked...hope so...I could use a new flying buddy with daughters mine likes playing with :D