Re: [PSUBS-MAILIST] Through Hulls Complete?

["James Frankland" <james@guernseysubmarine.com>]

Hi vance.

I just had another look at the kittredge design.  I'd forgotten that the through hull pokes out a bit as well, so there will be less stick out than i previously said.  There will be nearly 40mm of through hull to support the shaft outside the hull, so there will be only about 30mm of unsupported shaft before the start of the threads.   Kittredge has about 20mm with a "GAR DUR Plastic Washer" (whatever that is) as the bearing surface.

So 30mm of stick out before the threads start.  Is that so bad?

I suppose i could remake the through hulls longer.  Or support them somehow?  hmm, actually Emile's design has a support on the inside.  I could probably make that arrangement to fit as the shafts are long enough i think......

Thanks again.
James




----- Original Message -----
From: James Frankland [mailto:james@guernseysubmarine.com]
To: personal_submersibles@psubs.org
Sent: Tue, 28 Jul 2009 15:59:26 +0100
Subject: Re: [PSUBS-MAILIST] Through Hulls Complete?

Hi Vance.
I will use washers as you suggest.

As for the lever issue, i agree.  However, the photo is a bit missleading as i made the shafts quite a bit longer than i needed to allow me something to hold on the lathe.

I just measured how much "stick out" there will be.  I will pull the motors as close to the hull as possible and with a quick measure, i think there will be 70mm from the end of the threads (right at the top where you start to screw in the shaft) to the start of the penetrator.  Not much i can do really, it has to clear the prop.

The motor is pretty heavy as well, compounding the problem.  I suppose i could make some sort of support that holds it up closer to the motor pod?

Not sure until i fit it all together and have a look and see.
Many Thanks
James


----- Original Message -----
From: vbra676539@aol.com [mailto:vbra676539@aol.com]
To: personal_submersibles@psubs.org
Sent: Tue, 28 Jul 2009 08:09:13 -0400
Subject: Re: [PSUBS-MAILIST] Through Hulls Complete?

James,
It looks fine. You might want to consider two delrin washers between your stop ring and the hull penetration and a matching set inside to give you bearing surfaces without metal to metal contact. The real problem for me is the length of unsupported shaft between the thruster body and the penetrator. It's quite a lever compared to, say, Kittredge's design, which puts the thruster can right next to the thru-hull.
Vance







-----Original Message-----
From: James Frankland <james@guernseysubmarine.com>
To: personal_submersibles@psubs.org
Sent: Tue, Jul 28, 2009 5:41 am
Subject: [PSUBS-MAILIST] Through Hulls Complete?



Hi All

Have a look at my motor through hulls and let me know what you think.  I sort of
made it up from a design Emile sent me, Kittredge, and me.

I wasnt really sure what i was going to do, but i got in the workshop, started
and this is what i ended up with....

http://www.guernseysubmarine.com/index_files/Page20723.htm

The main 28mm bar screws into the Minn Kota motor pods.  There is 15mm bore all
the way through and then a 20mm bore at the motor end to create a "stop" for the
epoxy fill.

I intend to put 2 long 4mm brass rods all the way through and fill the entire 20
- 15mm bore with epoxy.

There will be a washer welded on to the outside of the bar to create a stop and
a plastic washer.  Also a square milled flat to attach the handle.  (all yet to
complete)

Question:  Do i need to score or rough up the inside of the bore to create
better adhesion for the epoxy?

And suggestions, thoughts?  I'm unclear with this bit, so any comments are
welcome, even if its "thats a load of crap, do it again".

Kind regards
James