[PSUBS-MAILIST] Exterior HP tanks and weights

Mon Oct 28 14:22:44 EDT 2013

Scott, what size HP tanks are you using, 80,s?

Rick

From: swaters 
Sent: Monday, October 28, 2013 5:29 AM
To: Personal Submersibles General Discussion 
Subject: Re: [PSUBS-MAILIST] Exterior HP tanks and weights

My first time in the water was discovering the weight needed. Once I knew that then I attached it to the landing skids and the drop weights. I also have a storeage compartment in the sub that allows up to about 200lbs, but that is mostly reserved for salt water trade off ballast from freash water. I calculated the scuba tanks moving to the out side to move a negative 84 lbs interior to close to neutral when moved to the outside so I need to ad another 84 lbs to compensate. Most of the passenger trim for me is done with the VBT.
Thanks,
Scott Waters

Sent from my U.S. Cellular© Smartphone

jimtoddpsub at aol.com wrote:

Scott,

I'm locating the HP's on the exterior for several reasons, but of course anytime you move something to the exterior you increase the displacement and therefore the amount of weight required to submerge the vessel.

Adding or subtracting exterior weights is fine prior to launch, but a real pain once you're in the water.  It's not always easy to add interior weights either when the sub is in the water.  I still have to come up with a way to conveniently stow and secure up to 250 lb of lead inside to compensate for different size pilots/passengers or diving with no passenger.

"Sub Design: A Study in Trade-Offs"

Jim   
-----Original Message-----
From: swaters <swaters at waters-ks.com>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Mon, Oct 28, 2013 8:47 am
Subject: Re: [PSUBS-MAILIST] Group Help Request

Hatch closure from both sides deffenetly a good one. I would say adjustable exterior weights. I hate the idea on chucking weights on the floor and then sitting on them. I am torn between that and moving the hp air tanks to the exterior to allow alot more room on the inside.
Thanks,
Scott Waters

hank pronk <hanker_20032000 at yahoo.ca> wrote:

Joe,
Why don't you take a vote on what the best improvement would be for a k sub or alike.  My vote would be for a hatch closure from both sides.
Hank

From: Joe Perkel <josephperkel at yahoo.com>
To: "personal_submersibles at psubs.org" <personal_submersibles at psubs.org> 
Sent: Monday, October 28, 2013 5:41:42 AM
Subject: Re: [PSUBS-MAILIST] Group Help Request

      I just love the world in which we live! Look what I found while waiting to take my daughter to school,.. http://www.quickparts.com/QuickQuote.aspx

      Isn't that just the coolest thing! The Star Trek synthesizer in the real world.

      Joe

      Sent from Yahoo! Mail for iPad 

From: Marc de Piolenc <piolenc at archivale.com>; To: <personal_submersibles at psubs.org>; Subject: Re: [PSUBS-MAILIST] Group Help Request Sent: Mon, Oct 28, 2013 10:46:58 AM 
      Never thought much about doing it at small scale.

      I suppose I would set up something like a wood lathe or a potter's wheel 
      and work in some very soft material like low-density foam. Once I had 
      the shape that I wanted, I suppose one could pour a mold around the 
      master, melt or dissolve out the pattern and cast the final part in some 
      suitable plastic, or even in aluminum if you were ambitious.

      3D printing seems like the ultimate way to do it, though - the accuracy 
      available is already better than what we would need, and if the inital 
      results are not perfect, making changes and printing out another 
      prototype is very quick.

      Marc

      On 10/28/2013 6:13 PM, Joe Perkel wrote:
      > How can a home builder maintain that contour 360 Deg out of "X" material?
      >
      > Joe
      >
      > Sent from my overpriced
      > iPhone
      >
      > On Oct 28, 2013, at 2:57 AM, Marc de Piolenc <piolenc at archivale.com> wrote:
      >
      >> Quick clarification: a properly contoured Kort nozzle, MARRIED TO A MATCHING PROPELLER, will increase static and low-speed thrust. Of course it won't increase power, since that comes from your motor. If you just put a shroud around your existing prop, you will be disappointed, and a shroud that doesn't do the job is overpriced unless it's free! Key ingredients for success:
      >>
      >> Prop matched to the shroud
      >> Shroud matched to the speed and thrust requirement of the vehicle
      >> Motor matched to the resulting prop
      >>
      >> Marc
      >>
      >> On 10/28/2013 8:33 AM, Jon Wallace wrote:
      >>>
      >>> What is the cost of having a true Kort nozzle machined by a CNC? I think
      >>> a 30% improvement in thrust for $30 would be great but I suspect
      >>> machining a Kort is going to equate to many hundreds of dollars, if not
      >>> reaching beyond a thousand.  When I look at the Snoopy underwater videos
      >>> it is difficult to imagine a kort nozzle really making any difference in
      >>> the operational experience given that the motors are operating very
      >>> slowly and pushing Snoopy around at about 2 knots (estimated).  The
      >>> props are designed for power, but that's what we want underwater.  True,
      >>> a kort nozzle would increase that power but what is the return on the
      >>> cost?  In other words, on a road with a speed limit of 30mph and no
      >>> passing zones it doesn't matter whether you have a 1.6 liter or 5.4
      >>> liter engine under the hood does it?
      >> --
      >> Archivale catalog: http://www.archivale.com/catalog
      >> Polymath weblog: http://www.archivale.com/weblog
      >> Translations (ProZ profile): http://www.proz.com/profile/639380
      >> Translations (BeWords profile): http://www.bewords.com/Marc-dePiolenc
      >> Ducted fans: http://massflow.archivale.com/
      >> _______________________________________________
      >> 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 
      >-- Archivale catalog: http://www.archivale.com/catalogPolymath weblog: http://www.archivale.com/weblogTranslations (ProZ profile): http://www.proz.com/profile/639380Translations (BeWords profile): http://www.bewords.com/Marc-dePiolencDucted fans: http://massflow.archivale.com/_______________________________________________Personal_Submersibles mailing listPersonal_Submersibles at psubs.orghttp://www.psubs.org/mailman/listinfo.cgi/personal_submersibles 

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