Magnetic couplings= next step to deeper dives for DIY ROVs?

Anything to do with Propulsion.
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Mareike
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Joined: Dec 8th, 2011, 1:41 pm
Location: Thailand

Magnetic couplings= next step to deeper dives for DIY ROVs?

Post by Mareike »

Magnetic Disc Couplings for an hermetically closed motor housing to avoid leakage in higher depth starting at 1.72 inch. the torque is also not from bad parents for a disc coupling starting 33$ each.. I use 1 N torque for a 225W brushless motor. Also for my gripper I am thinking to use them as it saves a lot of struggle with the Isolation and end stop. When the gripper reaches his end stop the coupling simply slips without wear and tear..
Check it out

https://sdp-si.com/eStore/Direct.asp?GroupID=1028
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bigbadbob
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Joined: Nov 28th, 2011, 10:24 am

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by bigbadbob »

This has sparked an idea in my brain. along with Steve's ideas at the bottom of this page- http://homebuiltrovs.com/magneticcoupler.html
cheers for the ideas folks.
I'm using 7 blade 75mm pc fans for my thruster props, pc fans use brushless motors where the large inner bore of the fan itself has a ring magnet in it which is driven round by the four phase windings on the stator.
pc fans are way too underpowered by themselves but i'm wondering if they could be adapted into a magnetic coupling driven by a decent motor.
i'll experiment and let yous know.
(magnets on order)
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fiveoversp
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Joined: Oct 14th, 2011, 12:53 am
Location: Coast of Maine

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by fiveoversp »

hermetically closed motor housing, have you seen this?? maybe we could find a larger version? http://www.ebay.com.au/itm/NEW-Brushles ... 0790275166
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bigbadbob
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Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by bigbadbob »

heres my first attempt at making magnetic couplings.
it still needs a bit of fettling to reduce friction and seal the end but i've proved the coupling strength is enough to stall the motor. The fan hub is held on by the magnets and lubricated by the water.

Image

Image
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PSCG
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Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by PSCG »

When and how are you planning to test the motor? Are you going to release the blueprints?
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Mareike
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Joined: Dec 8th, 2011, 1:41 pm
Location: Thailand

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by Mareike »

I have ordered them and wait that the will be delivered. I will make a complete photo documentation of my ROV starting from scratch. I hope it will run in 2 month time from now.
a_shorething
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Joined: Sep 10th, 2013, 5:26 pm
Location: New Jersey Shore

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by a_shorething »

Hey everyone. Thought I'd resurrect this thread because I just had the same idea myself. I'm in the process of 3D printing a propeller and the innards that will be required to rotate the magnet array.

Did the OP ever finish his testing or documentation?

Here's my prototype, the magnets would fit inside the fins.
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Zaibach
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Joined: Aug 13th, 2013, 9:50 am

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by Zaibach »

Just wondering if anyone has tried the curved neodymium magnets?

I sorta played around with something like this a few years back, well before I had access to a 3D printer. Didn't get too far largely because I couldn't wrap my brain around how to go about making bearings for it. Just saw the box with the magnets in it tho so I figured I would mention them since it seems now as it did then like they would be a good fit for a project like this.
a_shorething
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Location: New Jersey Shore

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by a_shorething »

Do you have a link?
Zaibach
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Joined: Aug 13th, 2013, 9:50 am

Re: Magnetic couplings= next step to deeper dives for DIY RO

Post by Zaibach »

Sadly like I said it was years ago I think I got the ones I was playing with off eBay. I was able to find some similar results by searching for Neodymium Arc but nothing that fits them exactly.

They were similar to this http://www.amazon.com/Neodymium-Motor-M ... B0012AUUAC only way less expensive and more plentiful. I think the whole lot only set me back like $25. I want to say it was for like 30 N45 magnets. Looking at the picture the ones I picked up had a little less width but they were slightly thicker.
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