Model Boat Mayhem

Please login or register.

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

Author Topic: Billings Fairmount reversing query  (Read 1897 times)

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Billings Fairmount reversing query
« on: June 19, 2017, 03:56:40 pm »

Hi guys finally got my Fairmount wet at the weekend and I am pretty impressed how she pulls and how she manoeuvres but only issue I have is she doesn't want to go in reverse even at full throttle


She won't even slow down for some reason even with props spinning away in full reverse


I used the standard running gear that came with the kit but can't see what the issue may be


Any tips are much appreciated


Tia


Graeme
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 20,488
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: Billings Fairmount reversing query
« Reply #1 on: June 19, 2017, 04:18:53 pm »

 
Can you post a couple of photos of the motors, couplings, props & rudder so we can have a look see?     :-)
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #2 on: June 19, 2017, 04:20:29 pm »

How do I post from my phone cos can never resize them
Logged

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #3 on: June 19, 2017, 04:38:21 pm »

This is the only pic I can get under 300kb


She runs off 2x 540 geared motors from component shop at 2.5 to 1 and then 4mm shafts
Logged

gingyer

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,588
  • Location: Glasgow
Re: Billings Fairmount reversing query
« Reply #4 on: June 19, 2017, 05:17:12 pm »

I had a boat like that, it was the plastic props didn't "bite" the water in reverse
changed to brass and got it sorted in an instant  :-))
Logged

nemesis

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 529
  • Location: North Shields. Northumberland
Re: Billings Fairmount reversing query
« Reply #5 on: June 19, 2017, 06:31:16 pm »

look at the curvature of the blades, it answers your question. Scale props, on the whole, are designed for forward propulsion. Go for brass props like the other member has advocated, at least you can tweak them to what you want, nemesis
Logged

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #6 on: June 19, 2017, 06:33:57 pm »

Thanks guys will try it out and see what happens
Logged

Mark T

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,549
  • Location: Dudley in the Black Country
Re: Billings Fairmount reversing query
« Reply #7 on: June 19, 2017, 07:13:49 pm »

I agree it could be your props. My boat try's to drag its self under on full reverse. I used 4 bladed brass props and different kort knozzles to the kit.

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #8 on: June 19, 2017, 07:46:14 pm »

Thanks Mark


I've just tried a set of 35mm brass on it with a massive improvement so need to get on the phone to prop shop tomoz but can't decide whether to replace with 45 mm or try squeeze 50mm in as there's a bit of a gap around the 45 plastics .


I am planning to change the korts at a later date but finances restricted me during build and watching your build has gave me some great help and ideas


Thanks


Graeme
Logged

Mark T

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,549
  • Location: Dudley in the Black Country
Re: Billings Fairmount reversing query
« Reply #9 on: June 19, 2017, 07:55:14 pm »

I know that some of the builders who do tug towing run their props as close to the korts  as possible for maximum drive. We don't really have that issue so my advice would be to get some brass props that give you some clearance but also do the job. I hope this helps a bit  :-)

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #10 on: June 19, 2017, 10:14:51 pm »

Yeah that's great thanks for that



Logged

david48

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 857
  • Location: Strathdon,Aberdeenshire
Re: Billings Fairmount reversing query
« Reply #11 on: June 19, 2017, 10:27:42 pm »


As has been said already ,brass props is the answer .I have just managed to get mine in my test pond worked no problem , only thing the stern thruster has a water leak ,still trying to cure it . Supposed to be retired but have some how been drawn in to work again .
David 
Logged
Two heads are better than one sheep head  as my old plant manager used to say

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #12 on: June 20, 2017, 12:19:45 am »

Hi I have a similar issue but opposite end . Seem to be getting water in through my bow thruster and she blowers bubbles when in use but my stern is completely sealed . I used water based epoxy poured into void area surrounding thruster tube once I had shaped my keel. Only other issue I have is the steering linkages I've used keep bending the rod on port side but think I'll have to adjust length or position of servo
Logged

Knowurrys

  • Shipmate
  • *
  • Offline Offline
  • Posts: 1
  • Model Boat Mayhem is Great!
  • Location: Lincolnshire
Re: Billings Fairmount reversing query
« Reply #13 on: June 20, 2017, 10:04:02 pm »

Hi, I had the same problem with my Fairmount, no power at all in reverse, it was finally cured by changing the ballast and getting the stern down to the water line, from then on no problems.
Hope this works for you.
Logged

Vts99

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 114
  • Clydebuilt = best built
  • Location: Lanark
Re: Billings Fairmount reversing query
« Reply #14 on: June 21, 2017, 12:33:39 pm »

Thanks I'm actually below the water line at the rear and above it at the bow to try get more pull on it as this was my theory first . I've had props delivered today from Simon at protean design and considering I ordered them around 3pm yesterday I must recommend his service.


Hoping this cures the issue but got to wait till Sunday to try it out
Logged
Pages: [1]   Go Up