Rewire...or not.

[iseeit]

I have a heavy lift X8 multi-rotor with 8 Tiger U8 motors and 26"CF props.
It has six motor wire for each boom (3 for the top and 3 for the bottom motors). Each wire is about 28" long, give or take.
I'm currently looking for some weight improvements so I was considered replacing the 12 gauge with 14.
Is the weight differences noticeable and worth while, or not?

 

[Av8Chuck]

That should be pretty easy to figure out without having to rewire your rig.

Another thing you might want to consider is instead of running three wires the length of your boom from the ESC's to the motors, for a total of six wires per boom, you might want to run just two 12 gauge power wires and mounting your ESC's next to your motors. That should cut down on the weight.

 

[iseeit]

Good idea but the ESCs are fairly large and would have to be mounted on the outside of the boom meaning the wiring would be exposed to 26"CF props beating down on them.
I'd rather not.

((28" x 3 motor leads) x 8 motors) = 672", about 56'

Does anyone know how much 56' of 12 gauge wire would weight?
Does anyone know how much 56' of 14 gauge wire would weight?

 

[Pumpkinguy]

If it was bare copper wire you would loose 185 grams. So let's say they plastic weighs another 50%. That gives your savings of 277 grams. Hardly worth it. Your x8 wouldn't even notice it.

 

[dazzab]

An X8 with 26" props and you are worried about the weight of wires? What are you lifting with that monster?

 

[iseeit]

You would think but...

This machine is designed and built for long(er) autonomous flights, such as infrared inspection of large solar farms , and as such could be configured to run with either 6s/12s.
I'd rather stay with 6s (24v) but with 4 16,000 batteries, at 4.4lbs per, I would be at 65% throttle without any padding factor, normally about 15%.
My calculation on a 6s configuration show expected flight times of about 42 minutes but at a 65% hover.
Maybe that's not a big deal but everyone seems to say 'oh my god...don't go over 50% and have a padding factor...', hence the question of wire weight.

I'm currently shaving off some weight on the gimbal and was looking at shaving some off the wiring.
I've had a couple of people tell me that 56 feet could add up to 1 lbs., or so.

If it is only 277 grams then forget about it but I think it's going to be more than that.

I unfortunately don't have scale that can accurately measure a short length of wire so that I can extrapolate the correct number for 56 feet.

 

[Pumpkinguy]

Buy yourself a little gram scale. I think I paid $10 for mine 4 or 5 years ago and I use it all the time.

 

[iseeit]

It's on my Christmas list and I was told...don't get or else

I have enough 12 gauge silicon to sample but dont have any 14, hence the question.

Can some one weigh a length of 14 for me?
I can do the math from there.

 

[twistedshifter]

Dang….how heavy are those infrared cameras? You loose a lot of efficiency with Coax. Probably much more efficient to run a standard Octo platform.

 

[iseeit]

It's not a payload weight issue, per say, it's more of a longest flight time possible, issue.

I'm trying to determine whether a re-wiring job will give me enough weight lose, therefore adding to the total flight time. We fly/or will be flying different missions such as solar farms, wind turbines and building envelopes. Solar farm, using autonomous flight requires as much flight time as possible and when you have 800 arches with 500,000 panel to scan you want to reduce the number of flights, if at all possible. This can easily be a 2 week job.

I had use to have an Octo (SkyJib 8) which worked very well. This X8 was drawing only 48amp at hover and although the winds were light...it didn't even move an inch, during GPS Att. hold. Not even and inch!
So the theory, for me, seems to be true...large motors, large props = low amp draw = longer flight times. Now comes the extra weight of a 3rd and 4th battery and to either stay with the current 6s (24v) setup or move up to the 12s (48v), which will draw even less power therefore more flight time. My unproven calculations show upwards of 40-42 minutes on a 12s setup.

Re-wiring is just one decision on my list.

If someone has a 5 or 10 foot length of 14 gauge that could be weighted...
I can do the math from there.

 

[iseeit]

Anyone know where I can get 100' roll of 14awg silicon wire?

 

[Hexacrafter]

Here are Several Options - Some are of higher quality than others...
http://www.progressiverc.com/prc-silicone-wire-by-the-foot-14-awg.html
https://www.commonsenserc.com/product_info.php?products_id=3241&osCsid=2h1o3p45uhtunik771a992jhp3

 

[Pumpkinguy]

So was I right on the weight difference?