[PSUBS-MAILIST] props

[hank pronk via Personal_Submersibles]

Alan,
Another idea, make a thruster with a prop at each end of the motor, what do you think?
Hank--------------------------------------------
On Sun, 12/14/14, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] props
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Received: Sunday, December 14, 2014, 8:04 PM
 
 
 Alan,
 Maybe it is better to make a prop that works in
 both directions.  I can afford to loose efficiency, that is
 better than mounting two thrusters in my case.
 Hank--------------------------------------------
 On Sun, 12/14/14, Alan James via
 Personal_Submersibles <personal_submersibles at psubs.org>
 wrote:
 
  Subject: Re:
 [PSUBS-MAILIST] props
  To: "Personal
 Submersibles General Discussion" <personal_submersibles at psubs.org>
  Received: Sunday, December 14, 2014, 7:04
 PM
  
  Hi
 
 Hank,I guess
  you would be getting the same
 thrust in both directions,
  butyou would
  be doubling the pitch of the propeller by
 doubling up, &
  there maybe a lot
  of turbulance between the propellers.There
 are
  propeller calculators that take a
 number of input variables
  like hp, revs,
 boat size,intended
  speed, diameter of the
 propeller & pitch. You leave one
  input
 out & it calculatesthat for
  you. You
 could call the two propellers one (add the two
  pitches together) & see what diameter
  it calculates for you at a given pitch &
 play around
  till you get the most
 efficientdiameter /
  pitch combination; then
 use the diameter but halve the
  pitch.I
  don't think I made a lot of sense, but if
 you go down
  that path I will explain a bit
 better.However
  given that submarines
 operate better with bigger diameter,
  lower
 pitch propellersit
  probably isn't a
 good idea going to two smaller higher
 
 pitched propellers.Alan
      
     From: hank pronk via
 
 Personal_Submersibles
  <personal_submersibles at psubs.org>
  
  To:
  personal_submersibles at psubs.org
 
   Sent: Monday, December
 
 15, 2014 10:38 AM
   Subject:
  [PSUBS-MAILIST] props
    
 
  Hi All,
  If I build a
 thruster
  with an extra long shaft, then put
 two props on back to
  back, one prop
 reversed.  Will the thruster perform equally
  in both directions?
  Hank
 
 _______________________________________________
  Personal_Submersibles mailing list
  Personal_Submersibles at psubs.org
  http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
  
  
   
    
  -----Inline
 Attachment Follows-----
  
 
 _______________________________________________
  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