* THE FORUM FOR ALL THOSE INTERESTED IN BUILDING AND OPERATING MODEL SUBMARINES *



Join the AMS - Registered Forum users can become members of the AMS and it's free ...... To join send an email with your name , address and phone number to amstreasure@googlemail.com


For further details of any events shown here also see the "Shows and Events" section on the forum

*STOP PRESS* Coronavirus. A lot of Clubs have already cancelled all activities. Check carefully before you plan any travel

.

CANCELLED because of coronavirus. Papplewick Pumping Station, Nottingham, Sunday 12th & Monday 13th April
CANCELLED because of coronavirus. Bournville Sub Day, Sunday 10th May 2020

. ,

Submarine, Boating & Sailing Weekend, Norwich MBC, Weekend of 25,26th July

,./
.
Model Boat Convention, Haydock Park (Cancelled this year)

.

Bournville Sub Day, Sunday 13th September

,,,,

Club Submarine Regatta, Furness MBC, Barrow in Furness, Sunday 20th Sept 2020

Who is online?

In total there are 6 users online :: 0 Registered, 0 Hidden and 6 Guests

None


Most users ever online was 180 on Tue Nov 05, 2019 6:03 am

Latest topics

» Seehund Drawing
Subs with twin props - alignment EmptyToday at 8:19 am by david f

» Yellow Submarine - Beatles
Subs with twin props - alignment EmptyWed May 27, 2020 11:03 am by david f

» Italian CB class from WW2
Subs with twin props - alignment EmptyWed May 27, 2020 10:55 am by david f

» Simple telemetry system for openLRS
Subs with twin props - alignment EmptyTue May 19, 2020 11:47 am by david f

» New member from Liverpool, England - Krick type v11b
Subs with twin props - alignment EmptyFri May 15, 2020 9:35 am by david f

» 3D printed sub kits
Subs with twin props - alignment EmptyFri May 08, 2020 6:42 am by SWEnick

» Smoke or Steam generator for submarine models?
Subs with twin props - alignment EmptyThu May 07, 2020 9:15 am by david f

» Piston Ballast Systems
Subs with twin props - alignment EmptyMon May 04, 2020 9:29 am by david f

» openLRS and 2.4 Ghz and Submarines
Subs with twin props - alignment EmptySat May 02, 2020 8:42 am by david f

Search

 
 

Display results as :
 

Rechercher Advanced Search

Most Viewed Topics

Piston Ballast Systems
openLRS and 2.4 Ghz and Submarines
Moebius Skipjack
Engel U177 IX D2
CSS HUNLEY
CSS PIONEER
New project - USS Nautilus
Revell 1:72 VIIC u-boat
Skipjack.part 2
John Robinson's huge Gato...

Statistics

Our users have posted a total of 11142 messages in 1824 subjects

We have 853 registered users

The newest registered user is dreamterre

    Subs with twin props - alignment

    david f
    david f
    david f
    AMS Treasurer

    Posts : 2100
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria
    • Post n°1

    Subs with twin props - alignment Empty Subs with twin props - alignment

    Post  david f on Wed Nov 17, 2010 4:28 pm

    The U class I am having a go at building is my first sub with twin screws.

    Usual practice in submarines seems to be that the props are at right angles to the direction of motion. Does anyone have a feel for what happens if the props are angled slightly up or down? Is this important? Does it give you bows up/bows down operation?
    • Back to top
    Tom(ADMIN)
    avatar
    Tom(ADMIN)
    AMS Forum Owner

    Posts : 3002
    Join date : 2010-11-05
    Age : 60
    Location : Nevada, USA
    • Post n°2

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  Tom(ADMIN) on Wed Nov 17, 2010 4:35 pm

    I wouldn't have thought it would make a great deal of difference to a relatively low powered sub, David...I do recall back in my multi-racing days prop shaft angles were important when using a high revving, high speed motor like a .65 glo motor, and even more so in the world of hydro racing, but I don't think you'd notice much difference in a sub.

    I stand to be corrected though...
    • Back to top
    david f
    david f
    david f
    AMS Treasurer

    Posts : 2100
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria
    • Post n°3

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  david f on Thu Nov 18, 2010 12:39 pm

    The reason I'm asking is that experience tells me that it is very difficult with a new model to get the right combination of motor, gearing, prop diameter and prop pitch to get the right current draw, model speed etc.

    Hence a bit of "wriggle room" with prop diameter is useful but twin screws don't give you much scope to increase the prop diameter before you start to foul the hull, rudder, stern planes etc (I'm thinking of the U Class.)

    So a little bit of scope to change the angle of prop shaft relative to the subs axis would be useful. So I hope you are right. Because yes we are not talking racing models here.
    • Back to top
    Tom(ADMIN)
    avatar
    Tom(ADMIN)
    AMS Forum Owner

    Posts : 3002
    Join date : 2010-11-05
    Age : 60
    Location : Nevada, USA
    • Post n°4

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  Tom(ADMIN) on Thu Nov 18, 2010 12:41 pm

    That's one reason why I like boats with single props...
    • Back to top
    david f
    david f
    david f
    AMS Treasurer

    Posts : 2100
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria
    • Post n°5

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  david f on Fri Nov 26, 2010 4:21 pm

    I have spoken with Nigel about this who indicates that the alignment is important.
    It is similar to the "thrust line" concept in model aircraft.
    Probably less significant in model subs but Nigel suggests that if you imagined extending the prop shaft to the bow , the line would be close to the bow at the waterline/
    • Back to top
    Tom(ADMIN)
    avatar
    Tom(ADMIN)
    AMS Forum Owner

    Posts : 3002
    Join date : 2010-11-05
    Age : 60
    Location : Nevada, USA
    • Post n°6

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  Tom(ADMIN) on Fri Nov 26, 2010 4:52 pm

    I guess you could align the props and shafts correctly and then use flexible couplings to hook the shafts to the motors? I always use high quality silicone tubing now for connecting prop shafts to motors...easy to use, easy to replace and very adaptable to differing angles between motor and prop shaft.
    • Back to top
    david f
    david f
    david f
    AMS Treasurer

    Posts : 2100
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria
    • Post n°7

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  david f on Mon Jul 04, 2011 1:01 pm

    Just adding to this, now that Dzik is complete.

    The props in the end were fitted parallel horizontally but the shafts were inclined slightly upwards, vertically - if you see what I mean.

    It doesn't seem to have created any problems - the bow does not dip when you throttle up etc. etc.

    This is my first experience of running a sub with twin props so some videos of using twin channel mixing to aid stationery and under way turns:

    https://www.youtube.com/watch?v=oy7Wxdo13bs

    https://www.youtube.com/watch?v=CQfYg0AbKAU
    • Back to top
    Tom(ADMIN)
    avatar
    Tom(ADMIN)
    AMS Forum Owner

    Posts : 3002
    Join date : 2010-11-05
    Age : 60
    Location : Nevada, USA
    • Post n°8

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  Tom(ADMIN) on Mon Jul 04, 2011 1:14 pm

    That's very impressive David, although I'm not too sure what that yacht skipper thought of you chasing him through the turn in the second video...
    • Back to top
    thegrimreaper
    thegrimreaper
    thegrimreaper
    Guest

    Posts : 119
    Join date : 2010-12-01
    Age : 60
    Location : Ellesmere Port
    • Post n°9

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  thegrimreaper on Mon Jul 04, 2011 3:36 pm

    Richard(Admin) wrote:That's very impressive David, although I'm not too sure what that yacht skipper thought of you chasing him through the turn in the second video...

    Yacht Capt probably thinking Dave looking for a firing solution,bloody targets getting in the way.

    nice video's David


    Mark
    • Back to top
    david f
    david f
    david f
    AMS Treasurer

    Posts : 2100
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria
    • Post n°10

    Subs with twin props - alignment Empty Re: Subs with twin props - alignment

    Post  david f on Tue Jul 05, 2011 8:20 am

    Yes,I only just noticed that when I was looking at the videos. With the mixer I can now do the marine equivalent of Harrier "viffing" to avoid impacts!

    Still Sunday morning at Barrow is as nothing compared with the "Free sailing session" at Alfold.
    • Back to top

      Current date/time is Mon Jun 01, 2020 4:56 pm