Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: 1 [2]   Go Down

Author Topic: surface drives / rudders  (Read 8964 times)

triumphjon

  • Guest
Re: surface drives / rudders
« Reply #25 on: April 26, 2010, 07:03:41 PM »

thank you guys , at least us older folks know how to biuld a proper boat useing whatever timber we can find or afford ! its far more enjoyable than buying some ready made moulded tea tray from the net ! !  O0
Logged

john54

  • Guest
Re: surface drives / rudders
« Reply #26 on: April 26, 2010, 07:35:37 PM »

Thanks for the Thanks  :-))Hope you get it sorted after Some of the eh comments {:-{
Logged

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 740
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: surface drives / rudders
« Reply #27 on: April 26, 2010, 11:16:02 PM »

Whilst not the best engineering job in the world - made out from brass and old fruit machine bits it gives you an idea of what can be made - the only power tool used was a battery drill and a big soldering iron



mounted a little too low - but it replicated the relative position as it would have been on the original layout of this 37" 'Fletcher' fibreglass hull - the uj allowing a horizontal drive as opposed to angled - and powered by a 700 motor on 2 x 8 cell nicad packs on a series /parallel switcher made from micro switches (from fruit machines) giving off - half speed and cor blimey!

Previously the same hull had two solid shafts with geared 540's on 14 cells with the shafts coming straight out of the transom and home made rudders either side


made from (yup!) fruit machine PSU brackets, cabinet hinges and other odds and sods


All the above were made when basically, I was poor - had a wife, three kids and a huge mortgage - not the flashiest stuff in the world but back then (80's) it all wasn't available on the net, ready made or cheap.....Kids nowadays don't know their born

Logged

Bill D203

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,974
  • not long now!!
  • Location: Sunny Stevenage
Re: surface drives / rudders
« Reply #28 on: April 27, 2010, 12:12:34 AM »

Don't kick your self. It looks OK and cost you very little so result all the way round.  Theres nothing wrong with having a go & learing from what you do as you go along. Been doing that for years now and i think i will for a bit longer to come.
 :-)) :-)) :-))
Logged
Roll On Mayday. Im off for a pint.   How Much!!!   WHEN do you need it!     No dear!    Yes dear??   Wot Now???  soon to be EX Chairman SMBC

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,502
  • Location: Blackpool
Re: surface drives / rudders
« Reply #29 on: April 27, 2010, 08:25:36 AM »

Bill not wanting to rock the boat but futaba 2.4 fasst works well in fast boats as it uses spread spectrum tech that moves between many diff channles constantly.NOT all 2.4 systems work on this principle some just hop between 3 channels these channel hopping ones are pants and a great way to lose your fast boat  O0.So not all 2.4 systems work with fast boats.
Logged

BJ

  • Guest
Re: surface drives / rudders
« Reply #30 on: April 27, 2010, 08:13:47 PM »

I've tried solid shafts as surface drive, trust me, it doesn't work...

Pick the bones out the three images - the Dateline Cherokee 2 IS a SOLID shaft boat and runs quite well with 25 as the grunt.
The diagrams were sent to me by a guy who has run fast electrics successfully on a solid shaft set-up based on piccies #21 & #68
Logged

john54

  • Guest
Re: surface drives / rudders
« Reply #31 on: April 27, 2010, 08:22:45 PM »

Thats what i meant in my replys it does work well  :-))Thanks for the pics Mate  ok2 sorted now i hope  :-)
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,502
  • Location: Blackpool
Re: surface drives / rudders
« Reply #32 on: April 27, 2010, 09:24:43 PM »

Might work well with leccy and small to medium nitro but it wont work well with 2 strokes,you wouldnt get the motor low enough nor far enough forward to get the angle shallow enough plus even if you could get the motor forward enough the balance would then be way forward.Me personally i wouldnt ever use a universal joint on anything fast,flexi drive is the best way and no more expensive than a solid shaft arrangement nowadays no matter what power plant you are using.Leave the universal couplings for the tugs and slow boats  O0.
Mart
Logged

BJ

  • Guest
Re: surface drives / rudders
« Reply #33 on: April 28, 2010, 10:46:31 AM »

Might work well with leccy and small to medium nitro but it wont work well with 2 strokes,you wouldnt get the motor low enough nor far enough forward to get the angle shallow enough plus even if you could get the motor forward enough the balance would then be way forward.
Mart

Let's try for the third time to post this (1st - piccie too large, 2nd - You have already posted)

See the piccie. The engine is a Thunder Tiger 25 and the balance is OK. The boat is typical of a cigarette in the it heels on the turns.
Logged

pompebled

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 586
  • Location: Sneek, Netherlands
Re: surface drives / rudders
« Reply #34 on: April 29, 2010, 07:09:13 PM »

Hi John,

A solid shaft and surface piercing drive in the Intercepter hull is no problem at all; I've just finished two 65 cm hulls with it and they run well.

The trick is to have a shaft that's as long as the correct position of the CoG allows for, the motor as far forward as possible, so the shaft exits the transom at a very shallow angle:

The propnut should be between 10 and 13% of the hull length from the transom, in your case between 60 and 78 mm.

The motor should be as close to the bottom, only the watercooling coil should still fit.

I use a bulkhead for the motor to spread the load, a good thing in an ABS hull:

Topview:


The motormount/coupling bell is a great benefit, no need to allign the motor and propshaft, this sorts itself out when the motor is bolted on, here in a 65 cm stepped hull:


Mind you, these boats run on electrics, but nitro shouldn't be a problem either, the principles remain the same...

Here's a clip showing the boat in action: http://www.youtube.com/watch?v=HLcMharve1k
So, yes, it works!

Regards, Jan.
Logged
Boaters are nice people

john54

  • Guest
Re: surface drives / rudders
« Reply #35 on: April 29, 2010, 07:14:17 PM »

We rest our case  ;)
Logged
Pages: 1 [2]   Go Up