Tarot 680 IronMan Hexcopter build, a few questions.

[RyanParle]

So once Christmas is over and done with and i can justify spending another £ 700+ on more "toys" I plan on starting a build of a Hexcopter based on the Tarot FY680 IronMan TL68C01 frame, so far I have put together a list of what i think would make a reasonable setup, pretty much everything comes from HK mainly because they seem to have a good range, but I have heard that they dispatch pretty much everything from china & their customer service can be a bit poor, so I am open to suggestions of alternative suppliers from the UK.
I have based my choices of components on reviews, other peoples builds seen around the web (YouTube, individuals websites ect.) and have made use to eCalc to try and make sure I have chosen a combination that will actually fly, although i seem to notice some considerable inconsistency regarding the weight (all up vs excl battery). So now it is time to ask the opinion of actual people who use these things about my choices

So here is my list so far:

Tarot FY680 IRON MAN 680 Hexa-Copter Carbon Kit TL68C01 - 600g
HK PilotMega 2.7 Flight controller - 32g
Quanum LEA-6H GPS - 38g
HKPilot Power module ~10g
HKPilot Telemetery Radio Set - 11.5
1355 Carbon Fiber Propellers CW and CCW Rotation with Dual Mountings - 90g
Aluminum Quick Release Self-Tightening Prop Adapter Set - 1 x CW 1 x CCW - 0g*
Turnigy Multistar 3508-640Kv 14Pole Multi-Rotor Outrunner - 588g
Afro ESC 30Amp Multi-rotor Motor Speed Controller (SimonK Firmware) -159g
FrSky DF 2.4Ghz Combo Pack for JR w/ Module & RX - 12.4
Turnigy 9XR Transmitter Mode 2 (No Module)
Turnigy 9XR Safety Protected 11.1v (3s) 2200mAh 1.5C Transmitter Pack

Conectors/Cables/Misc
XT60 to 6 X 3.5mm bullet Multistar ESC Power Breakout Cable - 35g
Hook and Loop Universal Tie Down - Flouro Yellow - 300mm

Video Kit
Tarot T-2D V2 GoPRO 3 Brushless Camera Gimbal and ZYX22 Controller - 200g
ImmersionRC 5.8GHz 25mW Video Transmitter - 22g
Quanum 7inch Auto Scan 32CH 5.8GHz Diversity Monitor With Built In Battery
Minim OSD v1.1 - 4g
GoPro Hero3+ - 74g

Total Weight Excluding battery 1875g *weight of prop adaptors ignored as motor includes adaptors that will not be used

I am having a little difficulty in choosing a battery/motor/prop combo that will give flight times around 20 mins of mixed-smooth flying (I don't plan on any acrobatics)

My first choice of the multi star 3508-640Kv motor / nano-tech 6000mah 2S2P 60C-130C / 1355 CF prop looked ok until I became aware of the recomendation to have the copter able to hover around 50% throttle, I was also under the impression that the higher the discharge rate the better, but I gather that this is not really the case. So I figure that I need a 3s battery pack instead, any sugestions? also if changing to a 3s battery pack it has opened up a wider range of possible motor/prop combinations.

Whilst I appreciate the need to have the hover at around 50% throttle for "recovery" situations I will eventually be using my Copter for film work so I don't need it to be particularly responsive.

Thanks for reading!

 

[Motopreserve]

That's a big list, so I won't try to address everything. But a few questions popped to mind.

Have you messed with the open source flight controllers before? If not, you may be best choosing a more plug and play option. The minim OSD can be a chore as well.

Make sure people are having no issue with the quantum monitor and the immersionRC transmission.

I know people have had good luck with the multistar motors. But some haven't. You can look into stepping up to SunnySky motors for similar pricing.

You don't necessarily need a high discharge rating for most Multirotors, but you will want to do the calculations based on your final motor setup. And it's definitely recommended to get as close as possible to the 50% throttle hover. Regardless of your typical flying, it will be more efficient and more importantly for the atypical moments.

Also might think of some cheaper props for the initial testing. Nothing plastic - but some HQProps or APC will be appreciated if you go down. Carbon can be costly while testing

Good luck and fly safe.

 

[shortsonfire79]

Also might think of some cheaper props for the initial testing. Nothing plastic - but some HQProps or APC will be appreciated if you go down. Carbon can be costly while testing

I'm working on a modded 680 pro and for starters I bought these props from HK.
http://www.hobbyking.com/hobbyking/..._1347R_SF_2_pc_CW_Rotation_US_Warehouse_.html
http://www.hobbyking.com/hobbyking/...CW_Rotation_From_Rear_2_pc_US_Warehouse_.html

Later, once I get the hand of flying without destroying props, I'll be upgrading to these. I saw them listed a lot in the 680 thread on Rcgroups with pretty good review. I haven't done a whole lot of prop research yet but these have worked for others.
http://www.rangevideo.com/t-stlye-m...ultirotor-propeller-cw-ccw-propeller-set.html

From what I understand, most people run 4s lipos on these rigs, as will I. What I had read about showed that a lot of people used 5000-8000 mAh. I'm also running Sunnysky V3508-20 580kv, so keep that in mind.

 

[Motopreserve]

I have never used the HK props you linked. But the fact that they are a mix should make them stronger than the plastic ones they sell.

The range video were a bit tough to balance. I know everyone loved them - which is why I gave them a shot. But either they didn't balance correctly or I got a bad batch

You might want to do a new search for decent CF props. Some newer, better clones may be available since I last had to stock up.

The 4S seems the best bet combo for weight and power. Do the math on your rig to see what you'll be hauling, and that will help you determine the size you can go with.

 

[RyanParle]

Thanks guys, i've only just noticed these replies here and now i have most of my parts, i have changed a few things,and now have changed to Zippy Flightmax 3s1p 8000mah batteries and turnigy Multistar 4822 690kv motors, I also decided to buy some cheap plastic 12x4.5 props.

Motopreserve: as this is my first multirotor i have not had any previous experience with open source flight controllers, but i have always preferred to make use of open source projects like this, in my opinion the APM project is one of the best presented open source projects i have seen in a while, the setup guides are very comprehensive & it also has a lot of features for a modest price.

I've pretty much got everything up and running but am having a few problems getting it in to the air. Once armed the props start spinning slowly as normal, then as i increase the throttle to the point the copter starts to lift, it is clearly lifting more on the left front corner than the rear right, the middle right hand prop and the right hand rear props appear to be spinning slower than the rest.
I have been through all the setup steps & Gyro, Compass, Radio, ESC calibration, the flight modes & failsafe's are set, the motor order & direction is correct, and the props are installed correctly.

Doing a little investigation i found that the outputs from the APM for the channels of the affected motors were quite a bit lower than the rest, when in "idle" (props spin slowly when armed) the props all spin at the same speed and the output of the APM is at 1060 across all channels I've had a look at it tonight, and now the outputs seem more even and the motors all look like they spin at a similar speed, I'm working over the weekend so i'll have to wait until Monday before i can have another go at getting it in the air, but at least things look more like it will fly than it did yesterday.

I thought i'd just mention the cheap plastic props from hobbyking: http://www.hobbyking.com/hobbyking/...on_2_pc_RH_Rotation_Orange_UK_Warehouse_.html

I wasn't expecting them to be very well balanced, but i was most surprised that when put on my magnetic balancer they were all pretty good, each one only requiring minor fettling to obtain a spot on balance.

 

[Motopreserve]

Sounds like you are well on your way. The behavior you mentioned on throttle up typically happens when the props/motors are incorrect - despite how many times we may have checked

The only other reason I've seen that happen is if the flight mode is set on an alternate mode in multiwii (Baro mode). Not sure if APM has that type of thing. Seems like you sussed it out though.

Good luck and fly safe.

 

[RyanParle]

Success!! I tried a launch last night after i got home and managed to get a hover but still had to apply a fair amount of correction to the roll and pitch to keep it level, so i landed it and took it back in side (it was getting late and didn't want to upset the neighbors) i had a quick look at the troubleshooting guide, it recommended to check the RC1_trim & RC2_trim and compare them with the RC centre values in the radio calibration, they should be similar values. I was seeing a value of 1427 for RC1_Trim & 1497 for RC2_Trim and the centre values were 1503, so i re-calibrated the radio. After this i removed the props & fired it up, hey presto the motor out values were all pretty much the same.

Tonight when i got home from work i decided to do another short test flight, i still had to apply a touch of pitch forward to take off but as soon as it was airborne it all leveled out and settled in to a nice hover, it does drift slightly to the right so i will probably dial in a touch of trim adjustment on the roll channel and hopefully it will be somewhere near.

At the moment i am reluctant to fly more than a couple of feet in the air as i am currently using a temporary "bodge" to connect the battery, when i ordered the batteries i took a stab in the dark and ordered a few XT60 connectors to replace the bullet terminals fitted to the battery, i didn't expect the cables from the battery to be 8AWG, much to big to solder in to XT60 connectors, so i have ordered a load of XT90 connectors which should be arriving this week, i will replace the XT60 connector on the APM power module with a pair of XT90's and swap the terminals on the batteries for XT90's and i should be well away. I'm also waiting on a power monitor to measure the current draw under load to calibrate the APM power module & a 3 axis gimbal.

I'll take some photos of my work so far and keep you all updated.

 

[Motopreserve]

Congratulations! Don't be too concerned yet with the corrections if you are staying low and during take off. Most FCs want a "bump" to get it in the air and up out of prop wash. The trim should take care of the drift if there is still one when you're airborne.

Great to hear you got it going. Best feeling!

 

[RyanParle]

Thanks Moto, I have just taken it out for another attempt, this time to analyse the vibration, took off relatively easy and got up to a hover about 2-3 metres off the ground, everything was looking good, hovered there with pretty much no additional input required to hold the position, just a slight tweek to pitch or roll to adjust for wind conditions. i hovered for around 30 seconds and came down for a nice soft landing.

I decided to have a second attempt, which wasn't quite so good, it took me a couple tries to get off the ground, but once i got in to the air it all steadied out and i decided to move around a litttle and get a feel for the sensitivity of the controls, they are possibly a little twitchy for my liking so sometime soon i will look at reducing the sensitivity. now it was time to come in for a landing as i did so i misjudged the height and cut the throttle just a little early, it came down the last foot or so pretty quick and snapped one of the 10mm diameter landing gear struts. i have heard of several complaints about the strength of the landing gear and now i know why, for now i will swap the broken piece over with one of the camera rails, and i will look at designing some triangulation struts to improve the strength of the landing gear. I am fortunate enough to work in the aeronautical composites industry so i should be able to get hold of some materials for this.

 

[Motopreserve]

Don't sweat it. You're going to have these misc breaks now and again. Glad it wasn't from higher, and only got one leg. I broke the 680 CF LG foot once just from rocking back and forth- replaced it with G10 and it's been great ever since. Might be an option.

 

[RyanParle]

I have just ordered a 1 metre length of 10mm od x 8mm id from EasyComposites here in the UK, which should be a little stronger as it has a greater wall thickness, it should be delivered tomorrow so i will replace both the feet with some of this, might add a few grams, but i think its a worthwhile trade off.

I also took it out on to some farmland near my house where I could fly without the worry of hitting anything and i got on pretty well, its a lot less daunting when you have a little more space, i used alt hold quite a bit to get a feel for the controls and i'm pretty happy with the setup.

 

[Motopreserve]

Nice!

I have often tested in my driveway - which seems quite big....until the props spin up and it seems to shrink down to the size of a pea