[PSUBS-MAILIST] Pressure proof motor

Mon Dec 11 08:04:23 EST 2023

 Ian, you aren't the only one with a propensity to avert social media which is why we keep the email list going.  Although I have an account on FB I do not visit it often and would prefer that it (and Zuckerburg) disappeared.
But back to submarines...Alan, what is the performance affect of reducing the voltage from 48 to 36?  I suspect you lose rpm but wonder if that translates to torque and thrust as well.  Is there anyway to calculate those losses?
Jon

    On Saturday, December 9, 2023 at 11:02:08 PM EST, irox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:  

Hi Allen,

Thanks for sharing that write up, I really appreciate it.

I do have hopes for brushless motors and oil

compensation.  At some point I'll pick up a cheap unit

and play around with. hopefully we can figure which

ones are not putting electronics in the motor bodies.

I was present when Cliff emptied the black sludge

out and immediately thought I should start thinking

about brushless motors, even if they aren't as suited

for low rpm applications like ours.

Also apologies for calling James (and not even

Spelling that correctly!). Power is out here and I

Am poor at typing on the phone.

Sorry about the extra work. My avoidance of Facebook

is for personal ethical reasons.

Thanks!

   Ian.

-----Original Message-----
From: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Dec 9, 2023 7:07 PM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] Pressure proof motor

Ian,I tried twice to send pictures but files must be too big for this format. The last time I only attached two photos.The Psubs facebook page has 900+ followers. I have photos & videos on two posts about the thruster.There is another post on an air compensator I built that may be of interest to you.The fb format is a lot easier to put up photos and videos on. Also you can post comments and "like" what someone has posted or said without them going out to everyone & filling up their mail box.But here is a portion of the failed mail..... Brushless 2200W rated to 48V but could run off 36V.I bought the bottom unit only as was half the price.Motor only weighed 15lbs (7kg).A lot of empty space inside the can. Probably take a litreof oil to compensate it. But lots of area to put in fill & drain holes. It has a skeg on the bottom which I will cut off (should I use it). The motor portion of the cut off skeg would be a good place to put a drain hole in. It has two lip seals and a dust seal. Two decent sized bearings. The o-ring groove & mating face were done well. The hole that the wire came out through was sharp on the edge; they could have rounded that to stop it wearing on the wiring jacket.It is a sensor-less motor, so no position feed back from sensors, but then the sensors are usually the first thing to fail. In my view it would be a much better option for oil compensation than a brushed motor like the Minn Kotta, where the oil can lift the brushes or be contaminated by wearing brushes. One post recently seemed to indicate that the compensating oil was degrading the brushes.At the front end there are holes that have been filled in with something. There may be thread in the holes to bolt on an anode. If not, they could be drilled out to put in an anode. The propeller is about 4&1/2 to 5" pitch ( cant remember the diameter & am out). Designed for pushing a boat up to 20ft. The motor is quite a large diameter to get more torque & is geared down, with the low pitched propeller, ideal for pushing a sub.There may be a better motor out there that doesnt require such a huge volume of oil or air to compensate it. If you are looking for a brushless option, some of the motors have electronics inside them, including large capacitors that will crush under pressure. Cheers Alan  

Sent from Yahoo Mail on Android

On Sun, 10 Dec 2023 at 8:55 am, irox via Personal_Submersibles<personal_submersibles at psubs.org> wrote:
Hi Jamie's,

Thanks for doing that and creating a write up of it.  I am interested

to know how it went. Would it be possible to get a copy of that? 

 Or a summary maybe?

The Facebook group is closed to non-facebook members, and

I am not going to join Facebook any time soon.

Thanks,

Ian 

-----Original Message-----
From: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Dec 9, 2023 10:38 AM
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] Pressure proof motor

James,I did two posts on Psubs facebook page about the motor.I pulled it apart for the second post.Alan

Sent from Yahoo Mail on Android

On Wed, 29 Nov 2023 at 2:07 am, James Frankland via Personal_Submersibles<personal_submersibles at psubs.org> wrote:_______________________________________________
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