Model Boat Mayhem

Please login or register.

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

Author Topic: brushless motor couplings and prop shafts  (Read 442 times)

Klunk

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,863
  • If you know who I am, please remind me!!
  • Location: luton, beds
brushless motor couplings and prop shafts
« on: April 25, 2020, 02:02:03 PM »

as above
what are peeps using.
this is for crash tenders etc using 3650 1400 kv motors.
used a standard red coupling but stripped the coupling.
im also wary about using these standard prop shafts as well. i only use the metal bearing ones, but im sure the rpm is not going to do thrm much good long term
Logged
SECRETARY - LUTON AND DISTRICT MODEL BOAT CLUB
full time penguin

DaveM

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 693
  • Why on earth do I do this?
  • Location: Nottingham
Re: brushless motor couplings and prop shafts
« Reply #1 on: April 25, 2020, 03:26:45 PM »

Both SHG and SLEC now make those couplings with a chunk of hard rubber between the two metal parts. I've used both types with 35mm outrunners - no problems. The SHG type offers more choice of diameter and thread/plain, but the SLEC ones are a lot cheaper! https://www.slecuk.com/boat-accessories/coupling-3mm-x-4mm-flexi
DaveM
Logged

Colin Bishop

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 10,803
  • Location: SW Surrey, UK
Re: brushless motor couplings and prop shafts
« Reply #2 on: April 25, 2020, 03:51:33 PM »

Modelboatbits also sell this type in a range of sizes. As Dave says they are probably the best for high revving brushless motors. No whirly bits to come apart!

Colin
Logged

Klunk

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,863
  • If you know who I am, please remind me!!
  • Location: luton, beds
Re: brushless motor couplings and prop shafts
« Reply #3 on: April 25, 2020, 04:36:03 PM »

hi Colin. the whirly parts not only come apart, but they melt the plastic splines!
Logged
SECRETARY - LUTON AND DISTRICT MODEL BOAT CLUB
full time penguin

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 20,230
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: brushless motor couplings and prop shafts
« Reply #4 on: April 25, 2020, 05:37:23 PM »


What about replacing the center bit with car water hose or heavy silicon tubing, silicon  Vacuum hose?
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

radiojoe

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,925
  • Treat every day as your last,, one day it will be.
  • Location: Gosport , Hampshire , England
Re: brushless motor couplings and prop shafts
« Reply #5 on: April 25, 2020, 06:17:42 PM »


Hi Klunk    I'm fitting the bonded rubber ones on my Huntsman very strong and they have a quite a lot of alloy each side of the rubber bit to act as a kind of heat sink just a thought.


Joe
Logged

Colin Bishop

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 10,803
  • Location: SW Surrey, UK
Re: brushless motor couplings and prop shafts
« Reply #6 on: April 25, 2020, 07:03:12 PM »

With those couplings they won't generate heat as there is no friction involved.

Colin
Logged

radiojoe

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,925
  • Treat every day as your last,, one day it will be.
  • Location: Gosport , Hampshire , England
Re: brushless motor couplings and prop shafts
« Reply #7 on: April 25, 2020, 07:30:19 PM »


I was thinking about any heat that may be transferred from the motor shaft.




Joe
Logged

Colin Bishop

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 10,803
  • Location: SW Surrey, UK
Re: brushless motor couplings and prop shafts
« Reply #8 on: April 25, 2020, 07:42:09 PM »

In which case you haven't lined it up right!  :-)

Best to use a sleeve when mounting the motor to ensure it is OK.

Colin

Logged

ChrisF

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 643
  • Model Boat Mayhem is Great!
  • Location: Warwick
Re: brushless motor couplings and prop shafts
« Reply #9 on: April 25, 2020, 10:20:17 PM »

I think Joe is referring to heat generated by the motor and transferred down the motor shaft?

In theory there shouldn't be any heat produced by a Huco type coupling if it is set up correctly as there won't be any friction. And in theory the bonded rubber ones could produce heat if they aren't correctly aligned due to the flexing of the rubber.

I use the Huco type on low powered models, but use the quality Raboesch ones, and on higher powered ones also use the bonded rubber ones. All set up with solid couplings of course.

Chris
Logged
Concentrating in the main, on the fine Fairey Marine boats, which is plenty for me to get on with!

Colin Bishop

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 10,803
  • Location: SW Surrey, UK
Re: brushless motor couplings and prop shafts
« Reply #10 on: April 25, 2020, 10:30:04 PM »

If enough heat is transmitted down the motor shaft to melt the coupling then there is something seriously wrong with the setup!

Colin
Logged

Klunk

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,863
  • If you know who I am, please remind me!!
  • Location: luton, beds
Re: brushless motor couplings and prop shafts
« Reply #11 on: April 26, 2020, 05:14:39 AM »

it was not heat that did mine in.it was slippage between the brass insert and plastic outer. it had worn the plastic splines. all couplings have a theorectical limit on them.
Logged
SECRETARY - LUTON AND DISTRICT MODEL BOAT CLUB
full time penguin

Taranis

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,798
  • Kirklees MBC/ Balne Moor MBC
  • Location: Yorkshire
Re: brushless motor couplings and prop shafts
« Reply #12 on: April 26, 2020, 08:17:59 AM »

I fitted the solid coupling to align everything perfect before actually glueing the motor platform to the hull.
I then fitted the alternative that Joe suggests with the rubber insert. I found that this was worse than the solid coupler so swapped them back. Sometimes the rubber part loses perfect alignment or balance.

Perfect



NOT good in my case

Taranis

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,798
  • Kirklees MBC/ Balne Moor MBC
  • Location: Yorkshire
Re: brushless motor couplings and prop shafts
« Reply #13 on: April 26, 2020, 08:46:30 AM »

it was not heat that did mine in.it was slippage between the brass insert and plastic outer. it had worn the plastic splines. all couplings have a theorectical limit on them.
You could glue the brass inserts in place perhaps? A builders adhesive sealant should do the job on a new coupling of course

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,442
  • You bark - I will bite!!!
  • Location: Fareham
Re: brushless motor couplings and prop shafts
« Reply #14 on: April 26, 2020, 11:36:30 AM »

If you keep the coupling length short silicone tubing on the huco inserts can transmit huge torque.


Bob
Logged
Officially a GOG.
Pages: [1]   Go Up