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[frogman3]

HI ALL I'm still building my tiger hull but I'm thinking ahead as I would like to have 2 motors driving 4 prop  shafts  I know this can be done by a pulley  and cam belt drive but how do I fit the pulley wheel to the shafts while fitting a universal join on the shafts  ? anyone know how an a diagram would be very helpful
chris

[malcolmfrary]

Make sure that there is enough bare shaft where the pulley is wanted.  Most shafts need a collar to act as thrust bearing, a pulley can double up on that job.

[D108]

Hello,
On my four prop hulls I tend to put larger motors on the inner shafts to provide the main thrust and two smaller motors on the outer shafts just so they turn. I tend to put 550s on the inner and 385s on the outer.
I did build a tiger many years ago and put the larger motors on the outer shafts, the turning circle was horrible. Better to have the power on the inner shafts to push water past the rudder.
I think having pulleys or gears would be more difficult to set up where as motors are easy to install
Bart

[morley bill 1]

Hi the belt should take up small alignment problems so you wont need to use u/js  bill...

[frogman3]

Hi the belt should take up small alignment problems so you wont need to use u/js  bill...

HI if I don't use U/J how do I fit the pulley wheel to the threaded end on the prop shafts ?
chris

[raflaunches]

Hi frogman3


On my invincible build I used 4mm diameter (non-threaded) shafts and used grub screws to attach everything together. See my picture for my setup (not the best I知 afraid).

[frogman3]

Hi frogman3


On my invincible build I used 4mm diameter (non-threaded) shafts and used grub screws to attach everything together. See my picture for my setup (not the best I知 afraid).



HI Nick cheers for the pic an info but I still need more info as you say  pic not great to learn from but cheers all the same
thanks chris

[frogman3]

Hi frogman3


On my invincible build I used 4mm diameter (non-threaded) shafts and used grub screws to attach everything together. See my picture for my setup (not the best I知 afraid).

[raflaunches]

Hi Chris


When I finish work on Friday morning I値l pay a visit to my invincible in the work shed and take some better pictures. I thought I had some better pictures of the set up but alas not on my iPad in my barrack block.

[frogman3]

Hi Chris


When I finish work on Friday morning I値l pay a visit to my invincible in the work shed and take some better pictures. I thought I had some better pictures of the set up but alas not on my iPad in my barrack block.

OH great Nick thanks that will be most helpful top view and close  up if poss    I zoomed in on your pic an I see you have got a cam belt drive on each shaft just what I'm looking for many thanks for your time an effort 
chris

[Taranis]

Nice job Nick


Click it to big it

[raflaunches]

Thanks Andy, didn稚 realise that the picture could do that!

[frogman3]

YES cheers Andy for the big pic and I'm hoping for some more pics from Nick on Friday
chris

[RST]

I think you're getting the MFA timing belt reduction drive set-up confused with how to drive 2 shafts from one input.  You obviously don't need a U/J with a belt drive unless you opt for these particular types.  Hopefully the pics before helps, I believe another member provided parts from MFA's website which showed belts and pulleys.  You could also have found the kits on Cornwall Model Boats -but they're pricey.  Just be wary though with belts, they should really be very carefully aligned.  O-ring type drives take tad bit more misalignment in my experience.

BTW:  Struggle to understand your posts but just seen the location -I get it now I read it hearing the accent. LoL! Love Norfolk area.

[frogman3]

I think you're getting the MFA timing belt reduction drive set-up confused with how to drive 2 shafts from one input.  You obviously don't need a U/J with a belt drive unless you opt for these particular types.  Hopefully the pics before helps, I believe another member provided parts from MFA's website which showed belts and pulleys.  You could also have found the kits on Cornwall Model Boats -but they're pricey.  Just be wary though with belts, they should really be very carefully aligned.  O-ring type drives take tad bit more misalignment in my experience.

BTW:  Struggle to understand your posts but just seen the location -I get it now I read it hearing the accent. LoL! Love Norfolk area.

HI  RST thank you for the warning of bein wary much appreciated  of the belts.But ive used the MFA plastic pulley  belt drives motor mounts on all my big models for the last 30 YRS an had no problems with them  but I must admit that ive never treid to run 2 sharfts off one motor.Thats the reason im askin for help on this subject
an you say I don't need a U/J  well how do I connect the motor sharft to the inner prop sharft  ? on both side's ? an what particular types do you mean as you have not said ? .An thank you for telling me about the kits setup from corrnwall  M/B an bein pricey an I just got to hope I understand  from Nick's pic's how his setup works
 as I know in theory but I need to know  in practical the parts no.s for the pulley's an the belt drive an prop sharfts  an  where t get them from an how he fixed the pulley's onto the sharft .But I have a little idea an that's fittin the pulley's with a collett fitted with a alan screw to hold the pulley tight to the sharft so I hope im right on this but will see after ive studied  Nick's pics
an im sorry if you have difficulty readin my post but as you say im from Norfolk lol  but thanks for your reply an instrest in my post
chris ps I should have called the cams timin pulley's  sorry about that but ive never had to buy these on their own  before

[frogman3]

Nick did you get your pulley's an belt drive 's from MFA ?
Chris
 

[Plastic - RIP]

For the cost and mechanical complexity, I'd avoid 2 motors/4 shafts and go straight for the 4 motors solution - so much simpler to install and no strange side-pressure wear on shaft bearings designed to have straight loads.

[frogman3]

HI thanks for your good advise but ive already done that in my big USS NIMITZ carrer hull as I had plenty of room
see link for pic https://ibb.co/pKTgXJC But in my tiger hull their is only limted space an be easyier in my opinion to do what this thread is about
chris

[raflaunches]

Hi Chris


My pulleys and belts were made by SHG Models (Staffordshire), they have different types and can be made from resin or aluminium (price varies of course and the aluminium ones are more expensive).
I have used both material types and the resin ones are more than okay for warship type models, the aluminium versions are more suited to fast large scale models like 1/12 scale ASRLs/MTBs etc.

[frogman3]

Hi Chris


My pulleys and belts were made by SHG Models (Staffordshire), they have different types and can be made from resin or aluminium (price varies of course and the aluminium ones are more expensive).
I have used both material types and the resin ones are more than okay for warship type models, the aluminium versions are more suited to fast large scale models like 1/12 scale ASRLs/MTBs etc.

HI again Nick thanks for info  i'll proberly take your tip an go for resin ones  but I can 't order them for a while as im still building hull an I don't know what size I need  but lookin forward to your layout pics ps have you had any probs with the prop  sharft bearins wearin  from the side pressure wear as described by PLASTIC ? an the resin pulley have they got collets fitted with a alan screw to tighen on prop sharfts ?
chris

[raflaunches]

Hi Chris


Yes they have moulded in collets with grub/alan screw in each pulley, if I remember correctly they have two screws per pulley opposite each other.

[frogman3]

Hi Chris


Yes they have moulded in collets with grub/alan screw in each pulley, if I remember correctly they have two screws per pulley opposite each other.

Great stuff  Nick that's just what im lookin for many thanks for info 
chris

[Colin Bishop]

Has anyone actually experienced sideways wear on pulley drive bearings? I rather doubt it. You are more likely to get wear from a slight misalignment of a conventional coupling or an off centre bore in the coupling itself. Both are common and lead to noise and vibration.

See my post #5 here:
https://www.modelboatmayhem.co.uk/forum/index.php/topic,63191.msg668026.html#msg668026

And topic here:

https://www.modelboatmayhem.co.uk/forum/index.php/topic,63191.msg667984.html#msg667984
Colin

[frogman3]

Has anyone actually experienced sideways wear on pulley drive bearings? I rather doubt it. You are more likely to get wear from a slight misalignment of a conventional coupling or an off centre bore in the coupling itself. Both are common and lead to noise and vibration.

See my post #5 here:
https://www.modelboatmayhem.co.uk/forum/index.php/topic,63191.msg668026.html#msg668026

And topic here:

https://www.modelboatmayhem.co.uk/forum/index.php/topic,63191.msg667984.html#msg667984
Colin

HI thanks Colin  for the info an yes I read your post in the link will see how I get on when I get that far 
chris

[John W E]

hi there, to answer Mr Bishop's question - the standard O rings that we use in the driving belt situation is in theory outside its specs - an O ring is basically designed to be crushed forming a seal - normally in a machined groove - either in say a piston or a joint between 2 flat surfaces.  They are designed to be stretched slightly as the material they are made from isn't given to stretching very far before snapping.   



Also for side loading shafts, we should really use ball races/roller races rather than phosphor bronze bearings as roller bearings displace its load throughout the radius of the balls evenly around the inner cage of the bearing


as a footnote - one should be able to get 4 motors in as I did in HMS Exeter and that is only 1:96 scale which should be a slightly narrower hull.
https://www.modelboatmayhem.co.uk/forum/index.php/topic,33734.msg350818.html#msg350818
John