Multi motor

[Walter TheakerParticipant @waltertheaker27031]

can any one help fitting more than one elec moter? if three fitted one left oneright turning propswhat about the center one? or can they all turn the same way? how many speed controllers? what size mottors and props for a 37" M.T.B? and do I have to fit three rudders? help please

[ManxmanParticipant @manxman]

Hi Walter

If fitting 2 or 3 props, then the outside ones would run in opposite directions,  The middle one can turn either way.  Do you really need 3 working props? – the middle could be a dummy, either fixed or free running.  This would save the cost of a motor and speed controller (say £30-£40).  I would always fit separate controllers, as if one fails you still have control of the model in the middle of the lake, just when your on your own!.  Rudders – are easy, if the model calls for 3 then fit them. all 3 will opperate from the same servo.

Ken

[Walter TheakerParticipant @waltertheaker27031]

thanks Ken

your right I don’t need to use all 3  however it is now nice to know how they work.

thank you angain

do you have any info on WWII MTBs 

[ManxmanParticipant @manxman]

No info on MTBs I’m afraid – I’m into tugs, but they all use props, execpt for the rag & sticks !

[ashley needhamParticipant @ashleyneedham69188]

Chaps. I am not up much on MTBs, but is there a need for 2 or more individual speed conbtrollers on , say an MTB with 3 props? I can see that it obviously helps with the turning etc on the other hand if you have THREE rudders..enlighten me please!

[Allen MarshallParticipant @allenmarshall36083]

Try looking at a site called pt-boats.com you will find just about every thing you need from John in Australia

[Dave WrightParticipant @davewright33400]

I  have made a schnellboot to 1/2 in scale with three torpedo 850 ,the outer two tuning outwards  and the center one only running when i need top speed with just on/off relay switch.I have fitted the three rudders just the same as the real one(wanting to keep it to scale. ) The schnellboats would do 40 knots+. Its a big model at 57inch and when on full power it maches the real thing,but you need pleanty of room!!!.I’v also made a fairmile dogboat, a vosper,a H.D.M.L and a T.I.D tug all to the same scale.The dogboat has four 550 with two 25 amp s/c  taking care of two 550 each.It will turn in its own lenghth if one side is in full foward and the other side in full reverse.

[Tony HadleyParticipant @tonyhadley]

Walter,

When using contra rotating props, do make sure the left handed prop is securely fixed, with either a small pin or a locknut. The direction of rotation will tend to unscrew the prop, so secure fixing is essential.

I have a 32" Dark Class MTB and this type of craft can soon drain batteries.

Good Luck Tony

[ManxmanParticipant @manxman]

I agree with Tony about ensuring the props are securely fixed.  I use both locknuts along with a drop or two of thread lock, such as Powerbond or Loctite.

Cheers – Ken

[Paul TParticipant @pault84577]

Good Morning Walter

When I fitted 3 motors to my MTB I used 2 speed controllers, 1 for the center motor and 1 for the 2 wing motors.

When in the water I used the center motor for chugging around the lake but when I needed the speed I would use the 2 wing motors as well.

The central prop was slightly larger than those on the wings which, as stated by everybody else, are left / right handed.

Ken is right about fixing the props to the shafts especially on larger high speed models I have bitter experience of loosing very expensive props even with the lock nut firmly fixed in place.

I found that I had to have all 3 rudders working as on just 1 rudder the boat just continued on in a fairly straight line.

Paul

[TelstarParticipant @telstar]

Walter  

In your second post nothing to do with Post office   You asked about Info on MTB’s  Osprey Vanguard do a book with some nice illustrations

look at   http://www.amazon.co.uk/British-Motor-Torpedo-1939-45-Vanguard/dp/1841765007

they even do Second hand copies

cheers Tom

[Tony HadleyParticipant @tonyhadley]

Hi again Walter,

The British Military powerboat trust have an excellent site — http://www.bmpt.org.uk/  well worth a look.

Re: – installation of the props I would recommend reading Glynn Guests item in the Model Boats special of Winter 2007. The item describes shaft lubrication and setting the thrust. This must be the best description yet of these important, but so often overlooked, parts of the models construction.

Happy model building Tony

[Walter TheakerParticipant @waltertheaker27031]

Motors,rudders and props

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