Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: Scewed 6 Blade Props  (Read 1531 times)

SANDALL

  • Shipmate
  • *
  • Offline Offline
  • Posts: 3
Scewed 6 Blade Props
« on: March 02, 2017, 03:18:28 pm »


   I have a pair of 60mm  6 Blade Scewed Props  will they be o.k on my 1/96 Scale Arleigh Burke ? .
Logged

dougal99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,326
  • Huntingdon, Cambs, England
  • Location: Huntingdon, England
Re: Scewed 6 Blade Props
« Reply #1 on: March 02, 2017, 05:41:10 pm »

I would have thought they were rather large, scale 5.7 metres. Will you be able to get the required clearance from the hull with the shafts at the correct angle?
Logged
Don't Assume Check

SANDALL

  • Shipmate
  • *
  • Offline Offline
  • Posts: 3
Re: Scewed 6 Blade Props
« Reply #2 on: March 02, 2017, 08:03:17 pm »


  Hi
   The Shafts already fitted ,& had a pair of 5 blade 60mm Props attached O.K .but through my neglect threw one whilst sailing  /.
   Just wandered if the 6 blade scewed are adequate for propulsion . Clearance NO PROBLEM  .
Logged

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 9,464
  • Location: Wollongong Australia
Re: Scewed 6 Blade Props
« Reply #3 on: March 02, 2017, 10:57:37 pm »

I had the pleasure of a guided tour of a DDG51 Class Destroyer in 1986, but the propeller size was not discussed {:-{.....however Google can help...

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwiolpbl77jSAhUHppQKHdUUAgoQFgg7MAc&url=http%3A%2F%2Fwww.dtic.mil%2Fcgi-bin%2FGetTRDoc%3FAD%3DADA582048&usg=AFQjCNFQrV7NE_rSczaDk04Nr1jtfB01gg&bvm=bv.148747831,d.dGo

This [slow loading but well worth reading] official article contains the final recommendations for the on the hydrodynamic build considerations for the DDG51 Bourke Class destroyers

Page 18 in the recommendations nominates that although 18 foot diameter propellers will cost more than 17 foot diameter propellers, fuel savings over time confirm the 18 foot CPP's will be more cost effective

So there is your answer   18 foot = 5486 mm divided by 96 = ~~57 mm

Does this surprise you?

Now the question of blade numbers?........the Class certainly had five blades :-))....not six  >>:-(

The other consideration...with all things being equal, a 6 blade propeller to identical design of a 5 blade propeller of equal diameters will draw ~~20% more power

Derek
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

Geoff

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,179
Re: Scewed 6 Blade Props
« Reply #4 on: March 03, 2017, 01:17:20 pm »

A bit unrelated but if the 6 blade draws 20% more power will it also give 20% more thrust so the revs can be lower so power consumption reduced!


Geoff
Logged

Colin Bishop

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 12,171
  • Location: SW Surrey, UK
Re: Scewed 6 Blade Props
« Reply #5 on: March 03, 2017, 01:27:03 pm »

It will put a greater load on the motor which will reduce the revs but power consumption will almost certainly rise. Whether the model will actually go faster on the same voltage is a bit 'suck it and see'.

Colin
Logged
Pages: [1]   Go Up
 

Page created in 0.09 seconds with 21 queries.