1st copter build (Tarot 680) - criticism needed

[DenisDespair]

DJI data link is a nice thing, but another 200+ USD. I though that there can be smth simpler

 

[meriachee]

The fy680 is quite capable of flying a NEX. The motors and props are too small. Don't forget that the more battery you add, the more weight you add resulting in a smaller flying time, and more load on the motors. I'm building the same platform right now, although, I've ordered the Tarot 2 gimbal for the GoPro. I find my GoPro4 Black in 4k does some amazing stuff and will quite probably get what I'm after. (we'll see)
Here's the current log of the build:
https://airrealvideo.wordpress.com/

Cheers
Gary

 

[DenisDespair]

meriachee, thanks for the link to your build
680 was an original idea, but now I'm up to 810. I have some thing to figure out yet, but I'll order the parts soon

 

[DenisDespair]

Ok, many thanks to everybody who took part in the discussion! I've placed orders for T810 frame and other stuff. Takes quite a lot of efforts to find everything I need in EU shops, since I don't want to bother with taxes and 3-4 weeks waiting.
Probably I'll start new build tread soon. But this is a looong project, I have a lot of other thing to do, work, sports, travel, approaching Stockholm Marathon..

Some more technical questions.
1. How essential is utilization of silicone-covered wires? I'm going to solder XT-90 connector to the power distribution board using 6mm2 wire (smth between 9 and 10 AWG) . Can I manage with normal "plastic" insulation, or are there chance that it will melt?
2. Typical XT-90 Y-connectors sold in web-shops are made of 10 AWG wire. XT-90 is supposed to handle 90 A current, but 10 AWG wire is only for 40 A. http://en.wikipedia.org/wiki/American_wire_gauge
Am I missing something?
3. I was reading some reviews about Turnigy 9XR and got impression that this is not very reliable piece of equipment. Taranis is in the same price range (or even cheaper). Does it make sense to look to Spektrum or Futaba?

 

[eskil23]

1. How essential is utilization of silicone-covered wires? I'm going to solder XT-90 connector to the power distribution board using 6mm2 wire (smth between 9 and 10 AWG) . Can I manage with normal "plastic" insulation, or are there chance that it will melt?

I think you'll do fine with normal plastic wire. If it melts near the connector when you solder it is not a big deal, because you are going to cover the joint with shrink-tube anyway. Silicone wire is softer and easier to bend.

2. Typical XT-90 Y-connectors sold in web-shops are made of 10 AWG wire. XT-90 is supposed to handle 90 A current, but 10 AWG wire is only for 40 A. http://en.wikipedia.org/wiki/American_wire_gauge
Am I missing something?

Those numbers are for domestic construction use. If you are going to route it through vp-tubing inside a wall, then you have to go with those numbers. In a multirotor is another matter.

 

[Motopreserve]

The silicone wire is much easier to deal with because of the flexibility - as Eskil mentions.

You'll be fine with XT-90 and 10AWG size (or equivalent). Remember you are calculating for mac burst, which hopefully you will never have to experience.

 

[AzViper]

Silicon covered wire gets its flexibility from the number of individual wires of the stated wire size. Sure silicon aids in the the being flexible, but its comes done to how fine each individual wire within the sheath. I have 1/0 wire with over 600 strains of wire within a neoprene sheath and this cable is very flexible.

 

[Motopreserve]

True. But all the silicone wire I've used is always stranded - not so for the harder coating. So it's safe to say if you order up some silicone - it is going to be flexible for sure.

 

[AzViper]

True. But all the silicone wire I've used is always stranded - not so for the harder coating. So it's safe to say if you order up some silicone - it is going to be flexible for sure.

I understand, just pointing out that the finer the wire and more strains of wire that makes up whether its 14g, 12g, 10g wire the more flexible it is. I use what we call entertainment cable (Welding Cable) in a lot of projects that need flexibility in higher gauge wire. The finer the strains the more stains it takes to make a gauge size in the wire. If someone is on the cheap go buy a couple feet of SJOOW, SOOW, SJO, SO from an electrical warehouse and strip the outer sheath off to expose the inner wires, these will be a flexible wire and usually with a neoprene sheath.

 

[eskil23]

The 680 with those motors will not lift the Sony Nex with a larger lens, and the gimbal it will take to balance it.

eCalc says it will, but the flight times are going to suck because you can not lift both camera+gimbal and a large battery. You'll have to stay with small batteries and accept flight times of a few minutes only.

Edit: I didn't realize that I've already posted this in this thread before. Sorry for the nagging. I'll try to lift a similar sized camera with my F550, but I realize that I'm pushing it. On the other hand, a larger build would be pushing my budget instead.

Edit2: Here http://www.blocket.se/vastmanland/DJI_F550_med_DJI_Wookong_M_58793113.htm is a guy in Sweden that sell his F550 with a NEX-5r. He claims he get 9 min flight time out of it with 6600 mAh 4S battery, but I doubt it.

 

[Motopreserve]

True. I think I've gotten to a point where I rule out a build very low flight times. If the efficiency is strained, as Eskil has mentioned, the flight times would likely be quite low.

The flight times may be so low as to render the build more frustrating that not.

Of course, this is just my opinion. You patience may vary

 

[Old Man]

Electricity conducts mostly on the outside surface of a wire, not usually down the center of a wire. Any wire that has many strands and presents more wire surface area is a better conductor than solid core wire for our purposes. That's what a solid EE told me anyway. How it handles heat and soldering, and provides for flexibility are other important considerations.

 

[eskil23]

Electricity conducts mostly on the outside surface of a wire, not usually down the center of a wire.

That's only true for high frequency currents. DC flows just as fine in the middle as on the surface.