Hexacopter confusion......Uhhh?

[midge5]

Hi All, as a vintage modeller from the 80's & since not flying helicopters and trainers for 30 years :cower: I have decided to start again & jump in at the deep end by building my own Hexa from scratch! but having lost touch and having somewhat of a fried brain physics has just escaped me, so I wish to get your opinion on this basic design and any info on the prop type/sequence, I know the design is possible but struggling on the CCW & CW arrangement and whether this will work well using an Ardupilot, sooooo......

with CW props on 1, 3 & 5 and motors mounted on the top of the arms plus CCW props on 2, 4 & 6 with motors mounted under the arms in the cofiguration shown in the pic work do you think? apologies for the poor graphic representation but its my first attempt with new software!

the the staggered arms will mean the props will be level with each other because of the alternate motor mounting.

Would be keen to hear your suggestions on the potential design & any problems like wrong props etc, as I was getting myself confused as to the use of all CW props because motors are mounted alternately......silly I know but I have lost any moments of clarity lol.....apologies for the apparent noobiness of an old timer :/

View attachment 18179

 

[SoCal Blur]

What's the purpose/advantage of stagering the heigth of the arms if the goal is to have all blades on the same plane? Is it just an issue of space? Your idea of CW vs CCW prop locations (alternating) is correct. Of course on the motors facing down, you would essentially be mounting the CCW props upside down on the motor so that still facing in the same direction vertically as if it were mounted to a motor facing upwards.

 

[midge5]

Hi SoCal Blur, thanks for your feedback, the reason for stagering the arms is no more than using materials I have in a different way to most, at the moment I have 2 Y shaped arm that articulate on a hinged centre, I was going to merge the 2 Y's to configure the Hexa shape and in doing this the height is just right for stagering the motors in the way shown, I could of course just do away with the hinged centers and just use the arms as they are with all of them being sandwiched between 2 center plates he same as a standard Hexa, I still might do that, its just that I liked this idea as I have never seen one, well not as yet anyway ;-) and thought i'd just test the water as it were with the valued opinions of MRF members before going ahead, I know like yourself there are many pilots with alot of experience here that maybe able to see a potential flaw with my idea, I will try and put the frame together roughly and take a picture which may make things a little clearer when seen ;-)

The frame will weigh approx 800g bare, I was also thinking of using 9 x 4.5 3 blade props with 1000Kv or 1200kv emax motors for each?

I have alot to learn again ;-)

View attachment 18184

You might guess what the frame is made from ;-) this is just laid out, not assembled in any way .....(try not to laugh :highly_amused: )

 

[SoCal Blur]

Interesting. The only "flaw" if you could call it that is that you are just making it a bit more difficult on yourself

You should look at eCalc www.ecalc.ch and play with some numbers so that you can get the most out of your build.

 

[midge5]

Interesting. The only "flaw" if you could call it that is that you are just making it a bit more difficult on yourself

You should look at eCalc www.ecalc.ch and play with some numbers so that you can get the most out of your build.

Hmm I don't mind difficult ;-) it'll be a challenge, or one hell of a learning curve. I did use ecalc to get a rough idea and I think from memory around 1100kv motors with 9 - 10 inch props was the most efficient but using 1250kv motors according to the ecalc showed quite a remarkable inefficiency when it came to current consumption & thrust so I was thinking being as 1000kv motors were 2/3 the price of 1100kv's that I would probably plumb for those ;-)

Thanks for your input, its much apprecaiated. :welcoming:

 

[SoCal Blur]

What are you planning to do with it? Is it going to be a heavy lifter? If so, it would be more efficient with lower KV motors ~400KV and bigger props like 14" + (if the frame dimensions can handle the prop size) & 4S - 6S batteries

 

[midge5]

Well yes it will eventually be used for carrying a DSLR on a gimbal, I am surprised 400kv outrunners will do the job with big props Hmm, I will have to wait until the hexacopter frame is complete and add the weight of the gimbal and cam, at a guess I wound think the whole lot will be 4 to 5 kg, thats useful info thanks SoCal Blur certainly something to ponder though I should imagine prop size maybe nearer 10 inch? I have a long way to go though as funds are limited so its a bit by bit project, plenty of time to try and work out the finer details - thanks again for your input ;-)

I think from a rough estimation and some digital scales that each arm can deal with a max of 1kg before things get too stressed it maybe more depending on final length.....

Cheers SoCal Blur

P.S. Apologies for my naievety, tech has changed alot in the modelling field over a (Ahem) few decades ;-)