My first Quadcopter build - your opinion is appreciated

[Steve_in_NJ]

I have been smitten with the multirotor bug. I am planning a build of a quadcopter, and in the meantime await my delivery from HK of a teeny tiny quad, so I can practice basic maneuvering. I am painfully aware that I am a newcomer planning to build and fly an expensive and fragile machine.

BTW the main purpose of his quad will be as a platform for shooting video whle flying FPV.

I invite (need) your feedback!

Here is a pdf of the list of bits and pieces so far, including cost, weight and links.
https://dl.dropboxusercontent.com/u/65762317/forums/Steve_v2.pdf

Here is what eCalc thinks of my build (hit CALCULATE to see the numbers)
http://www.ecalc.ch/xcoptercalc.php...apc_slowfly_sf&diameter=12&pitch=3.8&blades=2

Thanks much,
Steve

 

[jbrumberg]

Welcome Steve.

There are a few of us newbee builders who recently joined who have completed their first builds who will probably be stopping in to welcome you as well. I speak for myself, but feel free to post and ask questions on their build threads as well. We have been building and in some (most cases) crashing together so to speak. So we are pretty good on the rebuilding too

This is a good site with a helpful membership.

Take advantage of all the newbee stickers and and build stuff. There is a wealth of information available.

Post freely and often.

Jay

 

[jbrumberg]

Steve just a reminder not to forget that HK 10 pack of 3 pin servo connector wires to connect the Rx to the FCB. Everyone forgets them. I do not know anything about the gimbal and video, and FPV servo wire requirements. That's a heavy quad and a big battery too, but this is a video platform I can not access your eCalc. I can not subscribe at the moment (sad story) so that may be why I can not get into your data.

Enjoy your little quad

 

[Steve_in_NJ]

Here's a pdf of the ecalc page. Widen the view to read more clearly.
https://dl.dropboxusercontent.com/u/65762317/forums/ecalc%20march%2010.pdf
If could make the quad lighter/cheaper I would. It just seems to need it all just to get in the air, and for more than a few minutes.

 

[jbrumberg]

Your flight times look really decent with 13 mixed and 20 hover minutes predicted. Not too bad for 2632 grams of flying video FPV platform. eCalc looks pretty good. There are better interpreters of that data here, by my training I am closer to the :monkey::monkey:

I have no clue how much the battery drain from all those add ons will affect flight times.

 

[Steve_in_NJ]

Well for 200 grams I can add a 2200mah 2s battery and a BEC to bump down to 5volts, to drive the gimbal and other electronics, and only give up 2 minutes of hover time. Not sure how that compares to just driving the stuff off the big battery.

 

[Steve_in_NJ]

Just got the Ladybird QR. Works great. Me, I am not so sure about. This is gonna take a bit of time. After thrashing about inside for a few minutes, I winterized the quad (see picture) to protect it against the snow and headed out. Didn't take me too long to find a nice place to hang it about 20 feet up. It's back on the charger now, "safe" inside.

 

[jbrumberg]

It's all part of the learning curve. I am not ashamed to admit to using my Browning BPS 12G shotgun and 2 deer slugs to retrieve a wayward and tree entangled "toygrade". I shot it down, retrieved it, put a new battery in it, and it resumed flying like nothing had happened. There is a pine tree now called "Shorty" among the other pine trees. Trees avoid all my quads now. Vicarious learning. I can do this legally where I live. I am truly fortunate and I realize this.

 

[Steve_in_NJ]

OK here's what I am up to. I managed to buy the "Alien 560" frame during a rare moment when HK was NOT out of stock, and put it together (6 hours put in on that). I have a lot to say about THAT but not right now...let's just say the things they don't tell you about assembly could fill another set of directions! I have taken pictures and will post later about it.

Here is my current list-o-parts. I decided to just paste it all here rather than force folks to go to another page. One bit of good news is that it seems my motors are rated at over 6160 grams of thrust total at 100% with 12x3.8 props, and the AUW is 2658 grams more or less. That's a ratio of 232%, or right about where I have read it ought to be. I still have some playing to do with eCalc before I go on a shipping spree - not sure why my power needed to hover is coming in at >75%, given the thrust rating of the motor. I am still working on comprehending the math of it all, I guess.

BTW I am writing this post using Firefox, as posting here with IE is a disaster for some reason. Hopefully the copy-and-paste from Excel below doesn't get mashed up by the time you view it.

cost	item	weight
73.00	560mm frame	520	http://www.hobbyking.com/hobbyking/...ng_Quad_Copter_Carbon_Fiber_Version_Kit_.html				Turnigy frame	280	http://www.hobbyking.com/hobbyking/..._Carbon_Fiber_Frame_550mm_USA_Warehouse_.html
299.00	Naza-M V2 with GPS	67	http://www.helipal.com/dji-naza-m-multirotor-gyro-system.html
57.00	Naza iOSD mini	50	http://www.helipal.com/dji-iosd-mini-on-screen-display-module.html?gclid=CKmzrI_jgL0CFUtp7AodcXUAzw
123.00	gimbal and controller	330	http://www.hobbyking.com/hobbyking/...hless_Camera_Gimbal_and_ZYX22_Controller.html
160.00	(4) motors - sunnysky 3508s 380kv	428	http://www.buddyrc.com/sunnysky-v3508-29-380kv.html
7.00	(4) 12" x 3.8 props	50	http://www.rcplanet.com/APC_Propell...P12038SF.htm?gclid=CK_93bObhr0CFahlOgodeFEA_A
108.00	(4) T-Motor ESC - SimonK 25A 2-6s, No BEC	96	http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=84_215&products_id=2399
70.00	FPV transmitter 5.8GHZ 32 channels 600mw	21	http://www.hobbyking.com/hobbyking/store/__43722__Boscam_FPV_5_8GHz_600mW_32CH_A_V_Transmitting_TX_Module_TS832_RP_SMA.html?strSearch=5.8ghz 00mw
44.00	FPV receiver 5.8ghz 32 channels		http://www.hobbyking.com/hobbyking/...nnel_5_8Ghz_Auto_Scanning_Video_Receiver.html
22.00	5.8GHz Circular polarized antenna set		http://www.ebay.com/itm/131138586453
5.00	UBEC for 5V electronics (as needed)	8	http://www.hobbyking.com/hobbyking/...3A_UBEC_w_Noise_Reduction_USA_Warehouse_.html
81.00	6000mah 6S 25-50C battery 167x49x55mm	908	http://www.hobbyking.com/hobbyking/store/__11941__Turnigy_nano_tech_6000mah_6S_25_50C_Lipo_Pack.html
61.00	digital prism 7" LCD TV		http://www.ebay.com/itm/371014334020
300.00	GoPro3 silver	100
70.00	Turnigy 9X radio w/ receiver		http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=43905	http://www.aliexpress.com/item/Sunn...-rotor-copter-brushless-motor/1492925655.html
130.00	2 port (400watts x 2) Turnigy charger		http://www.hobbyking.com/hobbyking/..._400Wx2_Battery_Charger_Discharger_800W_.html
	misc wiring	80
$1,610		2,658	grams

 

[Steve_in_NJ]

OK I have crunched the numbers in eCalc endlessly and can't get them any better (I think). My only worry is that the "motor @ hover throttle" numbers are high, especially when I set the battery "charge state" to LOW.

Here is a webpage of mine that shows the eCalc numbers - three pages with everything the same EXCEPT the battery "charge state" is HIGH, NORMAL, and LOW. Please give me your opinion of all this. I started out with 12-3.8 props - the "motor @ hover throttle" numbers were even worse. On these pages I have 12-4.5 props.

Thank you for your input here.

http://stevenmichelsen.com/quad/ecalc_test.html

 

[wolph42]

you start out (full battery) with a throttle of 72% @hover speed. That's too high. It must be between 50 and 60%. So:
- less weight
- bigger props/higher pitch
- stronger motors (== lower KV)
- higher S batteries (but make sure your motors can handle it)

edit: I crammed your numbers in my personal calculator (to check balance between parts) and its all pretty balanced for one thing: your props. The motor/battery you have are ideally for 16-18 props, your frame allows for 15" props max so I would suggest you change the props for 15". The calculator is linked in my sig.

 

[Motopreserve]

Wolf is right - you can up the performance tremendously by swapping for 15" props. The other thing you can do is add another battery (carry 2), which in ecalc needs to be programmed by changing the configuration in the battery section to 2 "P." So your nbattery would read as 6000mah, 25/35C, Normal, 6S 2P

I just did a quick ecalc based on your original ecalc link and used the "Without Drive" function, using the weight of that frame in the model weight area. eCalc will calculate the weight of all the components that way. Came up with AUW of 2225 for 1 battery. Adding another battery obviously adds weight, but the flight times are impressive.

Good luck!

 

[Steve_in_NJ]

Thanks much for that! It's given me a direction to go in.
Question: eCalc's "flight time" and "hover time" always is dramatically different. What does it mean by "flight time" anyway? Full-speed-ahead traveling?

 

[Motopreserve]

That's right. The energy required to hover is far less than traveling directional/at speed. Hover is the least spent juice it gets, other than if it's sitting on the ground and you're just admiring your handiwork

where in NJ are you? I grew up in Fair Lawn. Bart, the guy who runs this forum is from western Jersey.

Scott

 

[Steve_in_NJ]

where in NJ are you? I grew up in Fair Lawn. Bart, the guy who runs this forum is from western Jersey.

Scott

<-----------------

(in Morris County, 45 miles due west of NYC)

 

[Motopreserve]

Nice. I do't get back there much. Try to spin around there during the holidays if I get the chance.

 

[p40whk]

I've got the same frame and with the FPV/GPS mount on you can only use 12" props. 15" props even with the mount removed would be cutting it close. I spent days hashing out different scenarios on eCalc as well and ended up going with the SunnSky 3508-20 (580Kv) motors and a 4S battery.

Here's a link to my eCalc PDF: https://docs.google.com/document/d/1JM4bp9p2KWCv0U7jBdWyu6REiXeK6je6r0ndonSqsy8/edit?usp=sharing

My mixed time is only about 7.4 minutes but keep in mind that eCalc only lists the sunnySky "X" motors, the "V" motors are higher revving so your actual performance will be different.

After I printed this, I changed to a 6000mAh 30C 4S batter and 12.5.5 props and my mixed time increased. Throttle for that was at 53%

If you haven't already ordered your motors you may want to consider these so you can use the smaller props. I'm still waiting for my PixHawk to arrive before I can test this setup but it's good to see other building the same frame. Let me know how yours turns out.

 

[Steve_in_NJ]

OK, here's new numbers for your amusement. I tried the Sunnysky S4100S and came up with a fair compromise, I think... I went with one 8000mah battery vs two 6000s... trying to economize SOMEWHERE.
https://dl.dropboxusercontent.com/u/65762317/forums/X4110S.jpg

 

[Motopreserve]

OK, here's new numbers for your amusement. I tried the Sunnysky S4100S and came up with a fair compromise, I think... I went with one 8000mah battery vs two 6000s... trying to economize SOMEWHERE.
https://dl.dropboxusercontent.com/u/65762317/forums/X4110S.jpg

thats looking damn good.

 

[Steve_in_NJ]

oooh-oooh. Even better with 14x3.7 props. flight time is 10.7 / 14.0 / 30.7 with throttle at 50% for hover.
https://dl.dropboxusercontent.com/u/65762317/forums/X4110S_340kv_14x3.7_props_8000mah.png

EDIT: Uh oh. As far as can tell so far 14x3.7 props don't actually exist. The best I can do is 14x4.7 at HK. Anyone seen 14x3.7 carbon fiber props anywhere?