Re: [PSUBS-MAILIST] Water nozzle propulsion

[Ray Keefer <psubs2001@yahoo.com>]

Hi Bill,

There is another step on the lost wax process. Once
the mold had hardened around the wax. The mold is put
into a kiln. At high heat the wax vaporizes out of the
mold.

This leaves the cavities empty for the moltant metal
to fill. Otherwise the wax may not completely
displaced by the moltant metal leaving an ill formed
duplicat.

Regards,
Ray

--- Akins <lakins1@tampabay.rr.com> wrote:

> Hi John.
> 
> Is your electric motor brushless or sparkless? Take
> care if you install it in your battery compartment
> without first isolating it from the batteries. Risk
> of hydrogen explosion.
> Just an idea, but after you form the nozzles from
> wood, have you considered using that to make a mold
> and pour the nozzles out of brass? Brass would be
> more corrosion
> resistant than aluminum or mild steel. You could go
> to a local foundry or even make the mold yourself..
> You could also use wax to form the nozzles
> and then pour the mold material over the wax, and
> then when the mold material had hardened and you
> drill a hole to pour your brass into the mold, the
> wax will evaporate and
> the brass will fill the void where the wax was.
> Called the lost wax process for molding an object.
> Unfortunately the mold is only good for one usage
> because you destroy it when
> you break it apart to get to the molded piece.  I am
> interested in these underwater water pumps for sub
> propulsion, but I know nothing about them. Is it
> something like the propulsion
> used for a jetski but with an electric motor instead
> of a gas motor? Or is it more like an enlarged bilge
> pump in operation? Or is it more like a submersible
> in pipe well pump?
> I only know about electric motors and propellers
> like on my wetsub. The water pump idea intrigues me
> because I like the idea of someone being able to
> install the electric part inside their sub
> and the rest outside and therefore not need any
> pressure compensation like you would on an electric
> motor with a prop. It would be great to see some
> video of this in action underwater.
> Bill Akins.
> 
>  
>   ----- Original Message ----- 
>   From: John Gaertner 
>   To: personal_submersibles@psubs.org 
>   Sent: Tuesday, April 11, 2006 7:46 AM
>   Subject: RE: [PSUBS-MAILIST] Water nozzle
> propulsion
> 
> 
>   Jon,
> 
>   No, right now I know the predicted rate of flow
> from the external water pump based on the known
> performance of my hydraulic gear motor and the water
> pump itself. It is 4 gallons per second, at full
> open. 
> 
>   I expect I will have to experiment with the shape
> of the nozzles to achieve the maximum thrust
> possible. I plan to make the nozzles shapes out of
> hard wood and then hand form them out of either
> aluminum or mild steel sheet metal. There is some
> data available on nozzle shaping and I hope to
> utilize it in my fabrication. 
> 
>   As to the question of noise, that is pretty easy
> to solve using noise absorbing/deadening sheet
> material like E.A.R. produces. I have a lot of
> experience installing it in commercial aircraft and
> it makes a remarkable difference. The DC motor can
> be isolated from the crew area by a simple bulkhead,
> and the mechanical "compartment" can be covered by
> this sound isolating material. I already know how
> loud the motor is as I have it running with the
> system on my test bench. It would definately be
> possible to install the motor in my lower battery
> compartment with little or no trouble. The hydraulic
> lines do not care where they have to be run in order
> to work.
> 
> 
>   John Gaertner
>   Keswick, VA 
> 
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 



************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 311
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************