Model Boat Mayhem - Forum

Please login or register.

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

Author Topic: Dumas tug Brooklyn, motors ?  (Read 346 times)

Zil

  • Shipmate
  • *
  • Offline Offline
  • Posts: 8
  • Model Boat Mayhem is Great!
Dumas tug Brooklyn, motors ?
« on: November 13, 2017, 01:47:53 PM »

dumas tug Brooklyn nearly done but my problem is which motor to use .I have a 6v decaperm with a 2.75 reduction gearbox one end and I was wondering whether to use the geared side or none geared end .the prop is two and three quarters inches ish in size .if not suitable which would be suitable ...cheers for replys {:-{
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,666
  • Location: North London
    • Dive-in to Model submarines
Re: Dumas tug Brooklyn, motors ?
« Reply #1 on: November 13, 2017, 06:50:31 PM »

Do you know the pitch of the prop? Also what kind of speed are you after. I would say you would need to retain the gearing if using the decaperm, as I doubt it would have sufficient torque to directly drive a prop that diameter with any efficiency.

Buccaneer

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 205
  • Location: Ringwood Hants
Re: Dumas tug Brooklyn, motors ?
« Reply #2 on: November 13, 2017, 08:02:27 PM »

For this size prop I swear by the Mobile Marine Models T12. Expensive perhaps at 46 but very smooth and bags of torque. I use an Action P80S 20 Amp ESC.
John
Logged

Zil

  • Shipmate
  • *
  • Offline Offline
  • Posts: 8
  • Model Boat Mayhem is Great!
Re: Dumas tug Brooklyn, motors ?
« Reply #3 on: November 13, 2017, 08:47:50 PM »

Thanks for reply can't remember pitch of prop as long as it goes at scale speed it will be ok if not will change to bigger motor .ever see a tug planing just need a big pond
Logged

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,666
  • Location: North London
    • Dive-in to Model submarines
Re: Dumas tug Brooklyn, motors ?
« Reply #4 on: November 13, 2017, 11:36:54 PM »

Well according to my motor data, a decaperm winds 6000 rpm at 6 volts. With 2.75:1 gearing, that gives an unloaded shaft speed of 2182 rpm. Assuming the motor loads up a bit we can say the shaft speed is likely to be around 2000 rpm if well matched to the prop. Assuming the prop pitch is around 1 to 1.2 times diameter, then the boat should motor along at around a brisk walking pace.

Zil

  • Shipmate
  • *
  • Offline Offline
  • Posts: 8
  • Model Boat Mayhem is Great!
Re: Dumas tug Brooklyn, motors ?
« Reply #5 on: November 15, 2017, 08:06:06 AM »

thanks for replies .. re mobile marine mobile models t12 would that be without a gear box and go direct drive and what sort of coupling would be needed .also would that be 6 or 12 v  :}
Logged

Buccaneer

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 205
  • Location: Ringwood Hants
Re: Dumas tug Brooklyn, motors ?
« Reply #6 on: November 15, 2017, 05:54:38 PM »

Hello Zil
Mobile Marine Models T12 runs without a gearbox. I use a normal coupling with 6mm plain insert for the motor and whatever you require for the propshaft. You could also use MMM safety Coupling with the appropriate inserts. All three of mine run off of a 12V 7 A/Hr SLA Battery. If you have any questions give MMM a ring, they are very friendly and helpful.
John
Logged
Pages: [1]   Go Up