4 ms·

presumably this? https://www.kickstarter.com/projects/847478159/the-t100-a-game-changing-underwater-thruster?ref=card https://www.kickstarter.com/projects/84747

presumably this? https://www.kickstarter.com/projects/847478159/the-t100-a-game-changing-underwater-thruster?ref=card https://www.kickstarter.com/projects/847478159/the-t100-a-ga... I am worried they allow water running through the assembly, sea water is very corrosive and can't be in contact with any interesting materials (e.g. high performance magnets). /* /* ok they use plastic bearings and stuff, not sure what the magnets are.

dammitcoetzee 12y ago
From the kickstarter: "The core of the motor is sealed and protected with an epoxy coating and it uses high-performance plastic bearings in place of steel bearings that rust in saltwater."
- tlarkworthy 12y ago
  still somewhat skeptical that an epoxy seal will last next to turbulent water with sea debris. I know other strategies are magnetic couplings. Still, maybe replacing cheap motors frequently will be cheaper than a long lasting one (if one exists??). Make sure your mounting plates are accessible!
  - BigDaveFromATL 12y ago
    i assume it'd be something better than just a standard epoxy. there's plenty of underwater-specific epoxies and coatings used in the oil&gas industry that'd hold up just fine.
  - gallamine 12y ago
    By way of reference, there is nothing comparable within 10x the cost of this thruster. If you're worried about longevity then perhaps $1,000/thruster is more reasonable.
    - tlarkworthy 12y ago
      Oh wow, I did not see the price, yeah that's crazy good.
ChuckMcM 12y ago
Thanks for the link, so they are using a brushless motor. I really like that solution for water integrity. I would guess they seal the magnets in epoxy. That would make it reasonably durable. The surfboard is interesting. Having listened to some of the issues the wave-glider ran into in order to operate autonomously on the ocean I expect the same sort of folks will come talk to them. I heard a story (and it could be just that), that one of the wave glider experiments was going to be to count whales along the California coast, the plan was to put an active sonar pinger on the robot and ping once an hour to see if there were any whales nearby. The story goes that the project was shelved when the Navy called and informed them they would not be putting active sonar pingers into US coastal waters.
- lotsofmangos 12y ago
  the Navy called and informed them they would not be putting active sonar pingers into US coastal waters This makes no sense. Active sonar pingers are on pretty much all boats apart from small dingies.
- b_emery 12y ago
  Here's a project that used a passive listening device on a wave glider: http://www.fondriest.com/news/wave-glider-robots-listening-tagged-marine-animals-part-wired-ocean.htm http://www.fondriest.com/news/wave-glider-robots-listening-t... The whale monitoring I'm familiar with is all passive listening as well. The navy has a long history of pissing off marine mammal experts by blowing things up underwater, so it makes sense that the Office of Naval Research wouldn't fund active sonar. So your recollection has elements of truth.

dammitcoetzee 12y ago

From the kickstarter: "The core of the motor is sealed and protected with an epoxy coating and it uses high-performance plastic bearings in place of steel bearings that rust in saltwater."

tlarkworthy 12y ago
still somewhat skeptical that an epoxy seal will last next to turbulent water with sea debris. I know other strategies are magnetic couplings. Still, maybe replacing cheap motors frequently will be cheaper than a long lasting one (if one exists??). Make sure your mounting plates are accessible!
- BigDaveFromATL 12y ago
  i assume it'd be something better than just a standard epoxy. there's plenty of underwater-specific epoxies and coatings used in the oil&gas industry that'd hold up just fine.
- gallamine 12y ago
  By way of reference, there is nothing comparable within 10x the cost of this thruster. If you're worried about longevity then perhaps $1,000/thruster is more reasonable.
  - tlarkworthy 12y ago
    Oh wow, I did not see the price, yeah that's crazy good.

ChuckMcM 12y ago

Thanks for the link, so they are using a brushless motor. I really like that solution for water integrity. I would guess they seal the magnets in epoxy. That would make it reasonably durable. The surfboard is interesting. Having listened to some of the issues the wave-glider ran into in order to operate autonomously on the ocean I expect the same sort of folks will come talk to them. I heard a story (and it could be just that), that one of the wave glider experiments was going to be to count whales along the California coast, the plan was to put an active sonar pinger on the robot and ping once an hour to see if there were any whales nearby. The story goes that the project was shelved when the Navy called and informed them they would not be putting active sonar pingers into US coastal waters.

lotsofmangos 12y ago
the Navy called and informed them they would not be putting active sonar pingers into US coastal waters This makes no sense. Active sonar pingers are on pretty much all boats apart from small dingies.
b_emery 12y ago
Here's a project that used a passive listening device on a wave glider: http://www.fondriest.com/news/wave-glider-robots-listening-tagged-marine-animals-part-wired-ocean.htm http://www.fondriest.com/news/wave-glider-robots-listening-t... The whale monitoring I'm familiar with is all passive listening as well. The navy has a long history of pissing off marine mammal experts by blowing things up underwater, so it makes sense that the Office of Naval Research wouldn't fund active sonar. So your recollection has elements of truth.