ROVworld Subsea Information

Register Today for Underwater Intervention 2017
ROVworld Subsea Information: Forums

View next topic
View previous topic
Quote
This is 3D printed Kort nozzle designed for DT700 / DT750 motors.
Image


Specifications:

Tested forward/reverce thrust at 12V

1A - 0,5/0,5 kg (0.5/0.5 lbs)

2A - 1,0/0,9 kg (2.2/1.98 lbs)

3A - 1,35/1,2 kg (2.98/2.65 lbs)

4A - 1,65/1,5 kg (3.64/3,31 lbs)

5A - 1,9/1,7 kg (4.19/3.75 lbs)

10A - 2,5/2,1 kg (5.51/4.63 lbs)

14A - 3/2,7 kg (6.61/5.95 lbs)

19A - 3,6/3,2 kg (7.94/7.05 lbs)

Efficiency (G/W) Thrust (G/Watts) (lbs/Watts)
at 1A: 41 g/w (0.09 lbs/w)

at 2A: 37 g/w (0.082 lbs/w)

at 3A: 31 g/w (0.068 lbs/w)


We use 6 of them in our ROV "AVATAR"
https://i.stack.imgur.com/eHXWCm.jpg
Image


But as an experiment we also tried these engines even as an underwater arm thrusters. At a current of 15 amperes per motor, the speed is 1.85 mph with a swimmer weight of 166 pounds.
Image


We seldom use them at 20A cause big current means very short battery run time. If you will use them at high power you should prepare DT700 for it. Our test show this two small screws can not keep the motor from turning at maximum load. Even if you screw them hard they cannot make a good hole. This can lead to a break in the wires and damage to the motor.
Image


It's recommended to drill a sink:
Image


Although most brushless motors can work in water, it is recommended to make some modifications (even included Blue Robotics). Over time (after 100-1000 hours) microscopic damage appears on the wire's protective coating. Leakage of current through these holes can lead to malfunctions in the ESC or RC controllers. Moreover electric current into these holes causes electrochemical corrosion, which leads to a rapid destruction of the wires (after 10-100 hours). To prevent this we should impregnate the wires with epoxy. The engine will operate underwater with increased power (5-10 times the nominal!), so it is necessary to ensure a good heat dissipation. To do this, choose an epoxy with a high thermal conductivity.
Image


Forward and back thrust is almost the same. In the event of a breakdown of the propeller it is very easy to replace it even underwater. Our robot has made more than a hundred dives with these thrusters and they have proven themselves very well. We use batteries on board and thanks to a small current consumption our robot works 6-8 hours continuously without changing the batteries.
Quote
Previously, we tested it in a 300-liter bath and strong turbulence prevented us from obtaining stable and accurate data. Now we did a test on the lake and got a higher thrust value. Upto 4.78 kg (10.5 lbs) (46.5 N) at 12V 25A.
Image
https://www.instructables.com/id/ROV-Thruster-105-Lbs-From-DT700-Brushless-Motor/

Display posts from previous:







View next topic
View previous topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum