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Discussion Starter #22
Dielectric oil...
Have you ever worked with that sort of thing?
After googling around, it seems too risky to immerse the brushes. I found some who had failure after doing so, and no one who said it was a good idea.
I didn't find any factory made oil filled brush type motors.

Maybe if I could make a seal between the commutator and the main body of the armature; that seems unlikely.

Even then, if the body was filled completely I feel there would be a lot of viscosity / resistance. If the body was partly filled, would the foamy oil blasting around in there be ok?
It sure would cool the armature.
 

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OLD TIRED CDN. MECHANIC
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I've been thinking about this.
Have you any experience of oil cooled DC motors?
I'm wondering if it could be oil filled, if the commutator + brushes would be ok in oil or if a seal would be required to keep those parts dry [that would be difficult].

What kind of oil? how full should such a motor be? what about froth, mechanical resistance?
Ihe only personal experience I recall was with large oil cooled alternators on highway coaches, as a bus maintenance mechanic 40 yrs ago. (so the technology is very old).

Besides supplying the needs of the vehicle itself, there were more that a hundred additional reading lights, aisle lights, washroom lights, not to mention all the A/C and heater blower motors to be supplied as well. The actual ratings elude me as it was a long time ago. I don't recall ever opening one up as they were on an exchange basis.

The were supplied with the same oil as the Detroit Diesel engines, which in turn went thru the engine oil cooler and heat was then transferred to the engine coolant closed circuit / radiators.

I do recall the systems were 24volt with 4 large truck batteries.
 

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Mark, nothing helpful to add to your situation, but as always love the photos. The video was great.:thThumbsU When you first went under the bridge I thought the sound of the engine was actually your barge scrapping the sides/top.:hide: BTW was that the impetus for the Beatles magical Yellow Submarine that I saw at the 2:55 mark?:laugh:
MikeC
 

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Discussion Starter #28
the same oil as the Detroit Diesel engines, which in turn went thru the engine oil cooler
That's interesting, thanks.


One of my neighbors bought the yellow submarine; it was an unpowered escape pod for an oil rig. He added a motor and hydraulic drive.
The tenant staying at my old place was really happy when it went away;
"6 times every day , a boat full of drunken tourists would start singing 'Yellow Submarine'!" he told me.

I'm putting a new muffler on the diesel too.
 

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OLD TIRED CDN. MECHANIC
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Hey! Maybe if the muffler is quiet enough....
Never mind :)
What...... the muffler on the horse ??

Hey, this is Amsterdam..... how about a beavy of bikini clad ladies powering that paddlewheel?:tango_face_devil:
 

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Discussion Starter #31
Went ant bought the motor + control today; 500 miles round trip.
after the first 100, the vibration damper on my car motor spun [again], so I had to go the whole way slow with no AC.
And it was hot.
So I hope the motor will work...
 

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forklift drive train is not a bad idea, but it is a very slow machine and relatively low duty cycle compared to a boat. A boat requires a lot of torque and you will want to have your prop matched to your motor's torque and speed. Electric motors have more torque at low rpm than at high rpm.

i would look at maybe a cushman type cart, or mining equipment.

golfcart motors and batteries are actually quite heavy duty, the chassis and axles and such are not.

you may look for a wrecked hybrid or electric car for a battery. the opal ampera/chevy volt batteries are very good, water cooled and do not wear like many others for example.

we look forward to seeing more info about this conversion.
 

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Discussion Starter #34 (Edited)
Electric motors have more torque at low rpm than at high rpm.

i would look at maybe a cushman type cart, or mining equipment.
You have to realize there is very little second hand machinery available where I live; when something does come up, it's almost always completely worn out and massively overpriced.

When I'm up where the boat is up in Holland, I have no time or resources. I have to work with what I have.

I searched wrecked electric cars in Portugal where I live; the cheapest at this moment is $12,000.

You're probably right about the duty cycle; something on the motor plate states "s3 25%", and that's probably it.

Electric motors are not all the same; this is a series wound motor, and apparently the rpm is very load dependent. I'm still trying to figure out the optimum motor speed so I can calculate the prop gearing. I think the rpm stated on the plate is at zero load, because 2,900 RPM seems a bit much.

I have some other work this week [fix mower, fix car, etc.] but I'll hook it up to some batteries and measure the no load rpm to see if it's close to what's on the plate.
If it's much faster, I'll know the plate RPM is what to aim for. If it does run at stated rpm, I'm back to not knowing anything.

First attempt to obtain big SS tube to make a water jacket fell flat.
If I can't get suitable tube, I might make a roller and bend plate.
That will be tough, because I'll need enough thickness to cut it on the lathe to exact size / shape.

Maybe the better strategy is to circulate glycol solution around the outside of the steel motor case, and use the heat exchanger already in the boat for raw water.
That would require 2 pumps, but in reality that's easier + cheaper than fabricating a water jacket from stainless.
 

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how about a radiator from a car with the cold water going through it and a fan blowing air through that and into the motor?

i'm not sure which would be more efficient, it may be better to just have a good size fan on the motor output and some ducting around the motor for cooling, vs running a separate electric pump or 2 off your batteries. do you need hydraulics for the rudder? or is it manual?

just throwing out some more ideas. good or bad, it may spark something even better.
 

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Discussion Starter #37
All the multi HP electric boats have water cooled motors; with all that cool water outside, it's just too easy to use it when the motor is purpose built.

Air cooling is what it has now.
A continuous duty 3-phase AC motor of the same power would be 4x the size, with big external cooling fins, and have 1/2 the heat production of the motor I bought.
Even when I water cool the case, I don't expect to achieve a 100% duty cycle. It will produce something like 2kw of heat!

That's the physics, inescapable.
I'm dropping the oil bath idea; I keep thinking of more ways that could go bad.
 

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Mark, the cooling you are seeking can be found in a motor controller.
Explained in the video.


Motor Controller Part 1




Check the BMW forklift motor conversion also.


Donewrken

:fing32:

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