As many of you now have been using your ROV's for some time, I am curious about how the motors hold up after regular use in saltwater.
Have any of you had any problems with them? How does the bearings hold up? and what measures do you take to keep the motors in good working condition?
I am building my own ROV now, and want to run my motors the same way as in the OpenROV just because it's much easier then building a watertight enclosure, but I am just a little concerned about how often I would have to replace my motors.
Thanks for any input you can give.
I think this is one of those questions that depends on who you ask. Personally I have not had salt water be friendly to my stuff, but I often get motors that have been passed on from someone who already tested in the ocean etc and have some corrosion to begin with. The official story is that if you spray your motors with silicone and wash them off after each dive then you only have to replace them every once in a while. It has been my experience when repairing ROVS that may not have been perfectly taken care of in this respect that the motors do have some pretty critical failures.
I am beta testing Marks motor upgrade discussed on this post now but he only gave me 2. So I will have to wait for the 3rd for ocean testing. I don't have any interest in fresh water because where I am we have such nice kelp forests so see myself as a good test subject in this respect. If you want to drive in salt a lot and not have to replace motors I would keep an eye on Marks work or follow along.
Other people may have different experiences but to me it seems worth it to explore motors upgrading if you plan on being salty a lot like I do. I'd rather invest a bit of time in them and not have to replace them, even if they are pretty cheap to replace. It's just a bit of hassle having things die on you. (I have a motor in front of me that's completely missing the bottom bearing, who knows how!)
I am working in salt water as well and am considering different motor builds. Magnetically coupled motors seem to be the right approach. What are your thoughts?
My thought is the more the merrier. I had some problems in salt today again but am running some tests to try to fix it now. Even without the corrosion issue salt really tests your shrink tubing/hot gluing etc and kills the ROV if things aren't perfect! Here's our OpenROV hot tub video but I filled it a bit more since this vid: http://instagram.com/p/kxkuI9AOqg/