Hello! Im new to this forum and im looking forward to spend more time on here to learn all about this subject!
So me and my friend are currently making a prototype ROV and we dont really wanna spend too much money at first on motors.
So my question is, what motors are pretty cheap and can be used for smaller ROVs?
And what is the best way to waterproof the motors? I've heard that you can use brushed motors underwater if you dry them out and lubricate them after each use, but that feels pretty risky, if theres any kind of dirt in the water, the motor will break i guess?
And if it leaks some water inside a brushless motor, its not easy to dry it out, right?
Im looking forward to some answers!
Kind Regards
Sebbe!
What budget motors is the best?
Re: What budget motors is the best?
Hi,
You are right, you can wet-run brushed motors but they won't have a very long life as you say, even in fresh water. In salt water, their life is generally very short.
I don't know much about waterproofing brushed motors but I think I've seen low cost methods whereby the motor is fitted in a plastic housing, like the plastic canisters photography film used to come in, and the shaft would be 'sealed' with wax. A cheap solution, but I don't know how good it actually is at keeping the water out for any length of time. You could possibly also fill the housing with a light oil, ideally Mobilect 35 but WD40 would probably work too, at least for a while.
Here's a website showing the wax-filled film canister method- https://www.instructables.com/id/Build- ... ter-robot/
More expensive solutions involve using o-ring seals but they are harder to make, and cause friction on the motor shaft which increases with depth.
Personally, I have chosen wet-running brushless motors because they are a lot more suitable than brushed motors for wet-running. They just need flushed with WD40 after every dive, and even if they do fail, they are cheap to replace. The down side is that they need a relatively expensive motor controller to run them, and it has to be the type used for cars, not boats or drones, as you need the reverse function. The controllers I use are about £13 each, the motors about £7 each. Add a propeller and I'm under £30 per thruster for the bought parts. Add my 3D printed parts and each thruster will end up costing me about £50.
Whichever type you choose, you will likely be stuck with it as your choice of motor type determines your method of control, and therefore your ROV will tend to be built around the motors. Choose wisely!
https://hobbyking.com is a good place to start.
Not quite complete £50 thruster
You are right, you can wet-run brushed motors but they won't have a very long life as you say, even in fresh water. In salt water, their life is generally very short.
I don't know much about waterproofing brushed motors but I think I've seen low cost methods whereby the motor is fitted in a plastic housing, like the plastic canisters photography film used to come in, and the shaft would be 'sealed' with wax. A cheap solution, but I don't know how good it actually is at keeping the water out for any length of time. You could possibly also fill the housing with a light oil, ideally Mobilect 35 but WD40 would probably work too, at least for a while.
Here's a website showing the wax-filled film canister method- https://www.instructables.com/id/Build- ... ter-robot/
More expensive solutions involve using o-ring seals but they are harder to make, and cause friction on the motor shaft which increases with depth.
Personally, I have chosen wet-running brushless motors because they are a lot more suitable than brushed motors for wet-running. They just need flushed with WD40 after every dive, and even if they do fail, they are cheap to replace. The down side is that they need a relatively expensive motor controller to run them, and it has to be the type used for cars, not boats or drones, as you need the reverse function. The controllers I use are about £13 each, the motors about £7 each. Add a propeller and I'm under £30 per thruster for the bought parts. Add my 3D printed parts and each thruster will end up costing me about £50.
Whichever type you choose, you will likely be stuck with it as your choice of motor type determines your method of control, and therefore your ROV will tend to be built around the motors. Choose wisely!
https://hobbyking.com is a good place to start.
Not quite complete £50 thruster