Author Topic: Designing a Hexacopter! (Read 207 times)

loganj13 · « **on:** February 12, 2015, 03:29:45 AM »

Hey guys, I am designing a 380mm+ hexacopter to carry my GoPro+a small gimbal for it. 3D printable, with an estimated weight coming in so far between 800 and 1100 grams. Currently only can fit 6in props, but I will be fixing that shortly. What I really need is some help with what gear to use. I've got my FPV gear sorted out, but am not sure whether I should run 3 or 4S and what size motors I should use. I am looking for longer flight times, at a slow leisurely aerial photography pace. What do you all reccomend?

bigMouse · « **Reply #1 on:** February 12, 2015, 10:06:59 PM »

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I am looking for longer flight times, at a slow leisurely aerial photography pace. What do you all reccomend?

Mini sized multi's doesn't fit very well with longer flight times, and leisurely aerial photography pace!
Need to build bigger, and for more efficiency go to a quad layout!

Quote

What I really need is some help with what gear to use. I've got my FPV gear sorted out, but am not sure whether I should run 3 or 4S and what size motors I should use.

The main problem with mini hexa's is that it's difficult to find where to place a camera and gimbal, other than slinging underneath!

Mini hexa's are quite powerful for their size on 3s with 5x3 props, and will carry a 2200mAh battery with ease, I suppose there would be a case to go to 4S if you want to load it down with gopro sized camera, gimbal, and fpv.

I have two mini hexa's, the one made with CF sheet, weight with a 2200mAh nanotech, but without cameras and fpv is 560 grams
The other is made from GF sheet, weight with a 2200mAh nanotech, Mobious camera, but without fpv is 610 grams

Motor/esc/battery choice:

My options would be:
1) 3S, 10amp esc's, 2204 motors, 5X3 props (don't like the wiring on some of these motors so wouldn't recommend it)

2) 3S or 4S, 12amp esc's, 2206 motors, 5X3 props (This is probably the most versatile setup )

3) 3S or 4S, 18amp esc's, 2208 motors, 6X4 props (This would be dynamite but haven't actually tested this configuration!)

The motor size reference (as I understand it) is first two numbers = bell outside diameter, second two numbers rotor magnet width/depth, more magnet = more torque!

No doubt there are a 100 other options!

loganj13 · « **Reply #2 on:** February 13, 2015, 01:31:48 AM »

Thanks for the info BM, I finally gave in last night and started designing arms long enough for it to use 8in props, which will be a big improvement! I'm thinking I'll go with a DJI E300 hexacopter set, which is $185 total, a great deal in my opinion, a mini setup would cost the sameish. My estimated weight was with GoPro, 2200+battery, and gimbal included, and the E300 take off weight is 1200-2400, so I'll be able to throw a huge battery on it I think

I had been hearing the same thing from many other people, that it just won't really work well or at all to run a mini hexa with gopro and gimbal and large battery, so I figured why mini? haha, anyways, Ill keep you guys posted in the 3D printing section!

bigMouse · « **Reply #3 on:** February 13, 2015, 09:57:08 AM »

yes whatever you choose, make sure the esc and motors are 4S capable, then if it turns out marginal on power you just have to stick a 4S battery in it!

No experiance with the mid sized hexa's, 8" props sound about right for a hexa, and squeeze in 10" for a similar sized quad.

BIRDS-EYE-VIEW.NL · « **Reply #4 on:** February 14, 2015, 02:37:26 PM »

Use a multirotor calculator. This calculates everything for you including lift, endurance etc.
Hope this helps to.

Wicher

bigMouse · « **Reply #5 on:** February 14, 2015, 07:15:45 PM »

How would you go about sizing a motor for a conventional helicopter?
Taking into account gearing etc.

BIRDS-EYE-VIEW.NL · « **Reply #6 on:** February 17, 2015, 07:46:04 AM »

you can calculate the lift of the blades. or you have to compare data with an already existing model. Since single rotors having more lift and fly faster it is sometime necessary that i build a custom fpv/camera helicopter for my clients to. biggest part of the market now a days fly with multi rotor since its much easier to maintain. So if you don't need much speed / lift / endurance then stay with a multi rotor.

loganj13 · « **Reply #7 on:** February 19, 2015, 03:39:29 AM »

Just an update guys, redid arms to fit 9.4 inch props, comes out at almost exactly 550mm motor center to center. All 6 arms fold down 90 degrees to make it take up MUCH less space. Not sure what I'm going to use for landing gear yet...However, I did make the choices on gear:

DJI E310 hex set
32bit alexmos gimbal controller
quanum 2208 gimbal motors
4S battery, currently planning on running 2 4000mAh in parallel, may go down a bit...
Naza Lite (hacked into a complete Naza M V2)

total weight estimated at 2.5kg/5.5lbs (reason I may be going down on battery size but definitely somewhere between 3000-4000)
Will make a new post in the 3D print section soon, frame about half way printed, making final adjustments, and ordering E310 in 2ish weeks