Thrusters / Motors

They almost got me to sign up for Nuke school as well. I had a nuke, sub, et recruiter in my office. He was VERY weird, super smart but weird. After I took the ASVAB they told me that the test sort of groups people that are similar in skills and personality into the same types of jobs. Once I realized that I could be working with more of the Nuke recruiter I went FC. I didn’t escape the weird though. :slight_smile:

I hope you don’t mind if I jump in here with a comment / question. I understand that this is a project, but what do you intend the end use to be? Photography, exploration, recovery, multi function, etc. Where do you plan to use it, fresh/salt water, Standing water or tidal / strong current? Do you want a large stable platform or a small nimble unit. All of these factors should impact your design, along with budget.

I am in the process of building a small photo recon unit for a project where we will be looking at tree trunks and main branching limbs in a flooded forest, 120’ deep. We are dealing with a large amount of suspended particulate in the water so I am trying to use a very low light camera to avoid the back splatter caused by bright lights. I also plan to use a 3 laser measuring system for size and depth of field. ( I notice you did not have lights or lasers in your list) The other piece of important equipment is a compass/ depth module for heading and depth.

I don’t mind at all. I derailed the thread. Thank you for getting me back on topic. I’m actually thankful you are willing to help.

To answer your questions:

  1. End use will be exploration.

  2. Operating environment will be saltwater 100% of the time after the project is completed. I do have access to the University pool before then. I am not adverse however to modifying the ROV’s motors after the assignment as been completed. The T-100 Thrusters while nice, might eat up half the funds my professor is willing to give me to help fund the project.

  3. Looked up on the NOAA site, they state the average tidal current is 0.7 as per 2011.

  4. The platform size I’m still debating on. 20"x 20"x15" seems like a manageable size constraint to me.

I completely forgot to list about cameras and lights, though they appear on my list I’ve written in my notebook. The water in this area is really dark, so I imagine I will need some powerful lights and have just started to look at options. Buying Off the shelf, or building my own assembly.

Thank you for listing the compass and depth module.

I have to remind myself that this is a school project and it is my first time. I’ve experienced scope creep already and have to keep removing bells and whistles I want to add. If anything to keep it easy for the control box. Less things to display / program.

@jwlj,
You might want to follow my OROV 2.8 motor conversion project to get an idea of what an OROV 2.8 looks like with Blue Robotics M100 motors and propellers in place of the DST-700 motors and Graupner propellers.
Regards,
TCIII AVD

I’ve been researching other items for my ROV and have come back to the motors.

A few questions.

If I were to do the OROV DST-700 or the M100 from Bluerobotics, can I make a housing for the motors to sit inside and then fill that housing with a potting material?

Would the motors overheat? Would such measures keep water from entering the motor through the shaft side?

@jwlj,
The Bluer Robotics M100 motors are designed to run directly in the water and require water for cooling and bearing lubrication.
Regards,
TCIII AVD

Thank you.

Is that the same with the DST-700 motors as well?

@jwlj,
Since the DST-700s are designed to run in air and have oil lubricated bearings, I would say that they need some kind of cooling as they will heat up as they are driven by the ESCs.
Regards,
TCIII AVD

Thank you sir. You are a huge help!

@jwlj,
Glad to have been of help.:slight_smile:
Regards,
TCIII AVD

Hello,
My name is Pedro Mariano Nowakowski, I live in Bariloche, Argentina. I am very happy to have found this beautiful forum.
I am starting to build my first rov. Sorry if my next question is very basic. I thought it appropriate not to open a new topic.
I chose this engine, trying to find something similar to the T200 but lower cost.

Now I have the problem of choosing the controller (ESC).
I never drove a brushless motor and can not find an ESC that allows me to do the reverse rotation (except RC cars).
Can you recommend an appropriate ESC?
Thank you

@pm.nowakowski,

Try here. This ESC will drive the thruster in forward and reverse.

Regards,
TCIII AVD

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thank you very much!!!

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Hi TClll,
Is the OROV DST-700 you recommend the turnigy DST-700?
What company sells the motors?

Thanks in advance.

@christopher4321,

The DST-700 brushless motors are really not designed for immersion in water so you have to make sure that they are properly cleaned and lubricated after each ROV dive.

I believe that hexTronik makes the DT700 brushless motor.

Try HobbyKing.

Regards,
TCIII AVD

Thanks for the quick reply.
So to be clear it sounds like I can use either the:
Turnigy DST700
or the
hexTronik DT700

as long as I clean and lubricate them.
Correct?

Thanks for the quick reply.
So to be clear it sounds like I can use either the:
Turnigy DST700
or the
hexTronik DT700

as long as I clean and lubricate them.
Correct?

@christopher4321,

That is correct.

Some users have removed the steel ball bearings and replaced them with ceramic/steel bearings to improve bearing life.

Regards,
TCIII AVD

Will do.
What is a good esc to use with that size motor, cost effective?
Chris

@christopher4321,

You need an ESC that can drive the brushless motor both backwards and forwards unless you only want to go forwards all the time then you can use an airplane ESC.

A good brushless motor ESC can be found here.

Regards,
TCIII AVD

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