Tether twister


#1

I've just done my first run of homemade twisted tether:

2 x 18awg equipment wire.

1 X 4H nylon cord .

It looks quite chunky but i was hoping to transmit 200w at 48v down 100m- there might be other wire with thinner insulation. Just starting to think about floats.




#2

Hi ¡¡

Good arrangement.

Have you thought on using polypropylene rope instead of nylon ?

Polyp.... is a lot lighter, and lighter than water. It would reduce the mass of the tether.

While in water, "effective weight" would be even more reduced, due to the rope buoyancy.

Regards


#3

Love the winder David. What a neat idea.


#4

Yes

Its an old fashioned rope making technique. Nice and simple. It does require 3 operators though.


#5

Hi

I tested your idea:

4mm poly rope with 2 conductors as with the nylon version.

In and out of fresh water.

Grams/m IN OUT

Polly 8.3g 26.7g

Nylon 10.5 22.5g

The poly rope seems to be about 6.5mm diameter and the nylon is about 5mm. I am still leaning towards the nylon to reduce drag. I also prefer the cord -think it might last longer.

I am thinking about making the floats out of barrier pipe sections with blanks in either end maybe with an additional o-ring on the seat.

http://www.toolstation.com/shop/Clearance/Plumbing/Blanking+Cap+15m...

Or maybe just heat the ends and squash them together.

Polypropylene cord dose exist but the only 3mm cord in 100m length i could find was going to cost £50.