[PSUBS-MAILIST] Group Help Request

Sun Oct 27 16:17:00 EDT 2013

The day after..   

"Alan James" <alanlindsayjames at yahoo.com> schrieb: 
Thanks Alec.
Forget Minn kottas, this Dutch man is really on to something.
http://www.youtube.com/watch?v=rZJTGqmtzBs

Alan

From: Private <alecsmyth at gmail.com>
To: Personal Submersibles General Discussion
<personal_submersibles at psubs.org> 
Sent: Monday, October 28, 2013 8:20 AM
Subject: Re: [PSUBS-MAILIST] Group Help Request

It would be fine as long as the total work being done is held constant.
In other words swept area times pitch for the custom prop equals swept
area times pitch for the stock one. That's assuming equal rpm. 

Once you put on the new prop, verify by measuring the amps drawn. If it
isn't drawing more amps it won't be heating up more than with the
standard prop.

Best,

Alec

On Oct 27, 2013, at 3:07 PM, Alan James <alanlindsayjames at yahoo.com>
wrote:

I am wondering whether it is a good idea to change the prop
size on the Minn Kotta. Or whether it would be good to get advice
from Minn kotta first. After reading the issues about sub sea motors &
overheating
I am a bit wary of increasing the load, amps & heat in the motor by
increasing
the prop size.
With regard to Kort nozzles.... I found a design on the internet, then
tracked down a bucket of suitable size & slope, fiber glassed around a
portion of it, then built up the thickness of the leading edge.
Alan

From: Private <alecsmyth at gmail.com>
To: Personal Submersibles General Discussion
<personal_submersibles at psubs.org> 
Sent: Monday, October 28, 2013 7:29 AM
Subject: Re: [PSUBS-MAILIST] Group Help Request

Hi Joe,

Thanks for doing this. I have a Minnkota 101 here that I can measure for
you, but I also have some suggestions for your consideration.

Oil or air compensation are both easy and trouble free, so I really
don't see much value-add in the magnetic coupling. Or in a hard case.
Ditto reverse, my trolling motor thrusters with 13 years on them have
yet to wear out the reverse washer, and it's not like I don't use
reverse.

Where I do see real room for improvement is with props and nozzles. The
stock props are very short pitched, so if you put several 101s on a
small sub for main propulsion, I suspect you would not get the cruising
speed that their combined horse power would otherwise achieve. In other
words, it would be like putting a big engine in your car but only having
first gear.

Emile shared with me that the nice kort on his stern thruster is off a
diving scooter. I researched those briefly and indeed they're in the
ballpark of trolling motor prop diameters, and some appear to be true
korts. Since kort nozzles are hard to make, ID'ing one that's a good
match would be really useful. While looking at scooters, I noticed some
have variable pitch props. By variable I mean adjustable with tools, not
adjustable underway. That could prove a big performance booster for our
application.

In summary, I'd encourage a focus on the prop and nozzle, as I've found
the standard seals and reverse to be perfectly satisfactory. My trolling
motors leaked for the first time in 2012, after 12 years of use. I've
left the oil in them for years at a time. When I finally serviced them
last year, there were cheap rebuild kits readily available. 

Do you need the measurements of the inside bits too? 

Best,

Alec

On Oct 27, 2013, at 8:29 AM, Joe Perkel <josephperkel at yahoo.com> wrote:

All Psubber Alert.

A handful of members in conversation off list are coming to the
conclusion that perhaps a best solution to the thruster issues
discussed, is to improve on what has been demonstrated to already be
viable. That is Minn Kotas as demonstrated by Snoopy, Idabel, et al.
Parts are readily available and inexpensive. Case in point here,..
http://www.northlandmarine.com/MinnKotaQuickRef.htm

Hank has graciously offered his efforts in modifying several he already
has on hand, and I am willing to put in many hours of CAD work to come
up with working drawings, with an eye on this armature in particular,..
http://www.northlandmarine.com/MinnKotaArmatureAssy92-100-216.htm

The goal would be to add a mag coupling, Kort nozzle, and true
reversibility to a package that is compact, (4" dia) and field
serviceable / replaceable. The end product result would be open source
to the PSUB community.

Immediate problem that needs a solution.

I need a lot of information and detail in order to proceed. Particularly
what I need is dimensioned section drawings of appropriately sized
models. Unfortunately, Minn Kota does not make this information readily
available as demonstrated here,...
http://www.minnkotamotors.com/service/ascs.aspx

We need help accessing this information otherwise the effort is hobbled
from the start. If anyone can help in this regard it would help
tremendously. 

Joe

Sent from Yahoo! Mail for iPad

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

-- 

Carsten Standfuß
Dipl.Ing.Schiffbau @ Meerestechnik
Heinrich Reck Str.12A
18211 Admannshagen

0172 8464 420
WWW.Euronaut.org
Carsten at euronaut.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20131027/42fcf77c/attachment.html>