[PSUBS-MAILIST] DC Systems Primer

Wed Oct 16 20:18:08 EDT 2013

Joe,
I am after the lost gold boulder of Kootenay Lake BC ( you can google that)    It is just a legend, but what good is a sub if your not looking for something.  Here in BC the lakes are pretty boring, so the sunken paddle wheelers and steam engines are fun to hunt down.  And maybe there is some truth to the lost gold story.  I live 3hrs away and there is also a sunken paddle steamer in beautiful condition in the same area.
Hank

From: Joe Perkel <josephperkel at yahoo.com>
To: "personal_submersibles at psubs.org" <personal_submersibles at psubs.org> 
Sent: Wednesday, October 16, 2013 4:50:45 PM
Subject: Re: [PSUBS-MAILIST] DC Systems Primer

Gee Hank, that's really too bad. I would have really liked to have seen that!

I'm really torn about 42" ID. Everything else gets on that same escalator. My timing is such that I can't possibly start on the hull until I'm 60 - 62 at best, I'm 53 now. However, I'm rightfully concerned that 36" ID could become untenable for later years.

Best I can do now is get my CAD files ready for a lightning fast build.

What gold are you after? A lost "forty niner"?

Joe

Sent from Yahoo! Mail for iPad 
From: hank pronk <hanker_20032000 at yahoo.ca>; To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>; Subject: Re: [PSUBS-MAILIST] DC Systems Primer Sent: Wed, Oct 16, 2013 10:21:51 PM 
Joe,
When I started working on Gamma, I had to do some very major repairs to the ballast tanks.   I came so close to converting it into your Alvin jr.  My wife talked me out of it and I am glad because I want a totally independent sub.  I need range and that comes from being steam lined.   We all want something a bit different.  I also like the look of all the crap hanging off the sub.  :-)
Hank
From: Joe Perkel <josephperkel at yahoo.com>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Wednesday, October 16, 2013 4:01:53 PM
Subject: Re: [PSUBS-MAILIST] DC Systems Primer

Hank,

With what I want to do, It wouldn't be nearly as clean as Gamma. I would want all manner of crap hanging off of the front. I'm in a great area for night diving, all manner of critters and colors come out at night..

As a kid, I fancied myself first a Marine Biologist, an Astronaut, or a pilot. 

I've done the pilot thing, so a mini research sub well satisfies that nerdy science kid still within me.

Joe
From: hank pronk <hanker_20032000 at yahoo.ca>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Wednesday, October 16, 2013 5:32 PM
Subject: Re: [PSUBS-MAILIST] DC Systems Primer

Hi Joe,
If you build a Nekton style sub, you can just cruise out to the  wreck with no tender.  I will be searching for lost gold in the spring with Gamma at 400 feet.  I have to cross about a mile of lake to get to the search area.  I plan to do that at depth.    This style of sub has a great range due to the shape.  The sub has only 2hp with a kurtis controller,  so simple and it cruises at 3.5 knots at 70 amps.  I do love your Alvin jr though.   I also am a huge fan of the K style thruster, indestructible heavy wound motor.
Hank 
From: Dan H. <jumachine at comcast.net>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Wednesday, October 16, 2013 1:26:03 PM
Subject: Re: [PSUBS-MAILIST] DC Systems Primer

Joe,

I have to plead ignorance on the BLDC motor.  I'm guessing it's some kind of permanent magnet field DC motor... Correct?   Typically they are smaller in diameter then a wound field type.  

For my rear thruster I got the last of the three horsepower motors George had.  So my rear thruster in pretty much as the plans show.  

My side thrusters are even a bit larger then the plans since I found two 3/4 HP brush type, 36 volt motors for very cheep in a surplus close out.  I built around them but similar to the plans.  

To get props for them I called Michigan Wheel and gave them my HP and RPMs and a description of my sub.  They recommended the props and sold them to me.  

When I was doing my wet testing, I put a amp meter in the motor power line and found the side thrusters were fine but the rear thruster was drawing a little to many amps.  A little hand grinding to reduce the area of the prop blades brought the amperage down to the max rating for the motor.  I don't know if that the best way, but it worked for me.  

Now if your thinking of building a true Kort nozzle your definitely going to have to do some experimenting.  Even the prop guards as called out on the plans effect the prop efficiency and so also the motor load.  

You may be better off to find your motors then figure out what you can attach to them, open prop, shrouded prop or Kort nozzle.  Anything will move the sub.  I have a total of 4.5 HP and I don't know if I could control any more power as the sub gets squirrelly when trying to travel fast.  When submerged, the side thruster are almost all that's needed.

Dan H.
----- Original Message ----- 
>From: Joe Perkel 
>To: personal_submersibles at psubs.org 
>Sent: Wednesday, October 16, 2013 2:08 PM
>Subject: Re: [PSUBS-MAILIST] DC Systems Primer
>Dan,
>
>What I was hoping to find was BLDC motors matching 36v 1800 - 3600 rpm, 1/2 to 2 hp range. They don't seem to be out there.
>
>I have matched up brushed motors with those specs at both Baldor and Leeson with the appropriate face plates. But, then we are back to the same large / heavy motors at least there in the $500 range.
>
>You have the standard motors on Persistence, what are the size and pitch of the respective props?
>
>I'm going to just have to suck it up and draw these up with new Kort nozzles.
>
>Thanks!
>
>Joe
>
>Sent from Yahoo! Mail for iPad 
>From: Dan H. <jumachine at comcast.net>; To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>; Subject: Re: [PSUBS-MAILIST] DC Systems Primer Sent: Wed, Oct 16, 2013 1:48:13 PM 
>Those high voltage DC motors are designed for variable speed drives where the power is first line voltage AC then converted to DC through a motor controller for accurate motor speeds and torque.  They aren't practical for a battery powered system.
> 
>For battery powered systems your probably better off to stick to the lower voltage motors.  With an inverter I guess you could convert the battery power to high voltage AC then convert it to DC, but I'm pretty sure you'd find it impractical with the extra equipment.  
> 
>It's hard to beat golf cart controllers for speed regulation and there's tons of them out there.  Battery powered floor scrubbers use a variety of DC motors too. 
> 
>Dan H.
> 
>----- Original Message ----- 
>>From: Joe Perkel 
>>To: Psubbers Mailist 
>>Sent: Tuesday, October 15, 2013 11:02 PM
>>Subject: [PSUBS-MAILIST] DC Systems Primer
>>Since my Navy "A" school is some 30+ years ago, I need a little help in trying to understand and match up something close to Georges motors. What I dont understand is why is there such an array of DC motors in the 1 - 3 hp range with wildly varing input voltages?
>>
>>If you notice those Tecnadyne thrusters have stupendous input voltages up to 330vdc. I dont understand why and need a primer on DC systems for this application. Can anyone point me to one?
>>
>>What I'm trying to do is to slim down the housing, get more bollard thrust from the prop by adding a real kort nozzle, and use a mag coupling instead of a shaft seal, all else remaining essentially the same.
>>
>>I want to slim down Georges T-Rex cans with similar power specs, but new and improved components, keeping the items conducive to homebuilding, like the housings and mountings, electrical penetrators, shaft seals if I cant do mag couplings. 
>>
>>What I've found so far http://www.baldor.com/support/literature_load.asp?LitNumber=FL1210  fractional hp and up to 3 hp @ 1800 rpm but, here again @ 320vdc !?
>>
>>Whats attractive about this one is the dimensions, 6.5" on the mounting flange would fit quite nicely in the 6 nom SCH40 pipe which is 6.625"
>>
>>But I dont know what im doing with regard to the input voltage / output power / torque relationship and how to match this all up correctly.  All Ive confirmed so far is that Georges motors were TENV (totally enclosed non-ventilated), 36vdc @ 1800 to 3600 rpm for 1/2 and 3 hp respectively.
>>
>>Joe
>>
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