By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Dremel

Dual prop question

All Topics | Latest Posts

Search for:  in Thread Title in  
Neil Powell 121/08/2021 20:33:19
49 forum posts
14 photos

Hi quick question.

If i have 2 LH(at least i think they are LH) Props on a dual prop boat will the boat naturally steer in one direction? i know from flying dual prop RC planes that if the props aren't turning in opposite directions the plane can suffer from unwanted banking.

Thanks

Neil

ashley needham21/08/2021 21:38:28
avatar
7394 forum posts
159 photos

Neil. Yes, basically.

BUT it may not be that noticeable and easily trimmed by a bit of rudder.

Ashley.

Edited By ashley needham on 21/08/2021 21:39:31

Neil Powell 122/08/2021 08:36:59
49 forum posts
14 photos

So looking at the stern of the boat my props run counter clock wise. Will that make the boat go left or right?

Richard Simpson22/08/2021 11:11:47
avatar
766 forum posts
371 photos

Props tend to "walk" in the direction of rotation so, if they rotate anticlockwise it will have a tendency to move the stern towards port.  This can them make the boat steer slightly to starboard.

 

 

Edited By Richard Simpson on 22/08/2021 11:13:22

Paul T23/08/2021 12:21:07
avatar
7335 forum posts
1229 photos
2 articles

Hello Neil

I used to fit contra rotating props to my twin engined boats which, whilst correct, were expensive and ultimately a waste of money.

As Uncle Ashley points out a slight trim adjustment on the rudder control solves the problem of 'propwalk'

However if you wish to avoid the corrosive comments of the numerous rivet counters then you should either fit contra rotating props or ask them for the correct sequence of rotations on a triple engined boat.

Paul

Charles Oates23/08/2021 13:53:37
avatar
642 forum posts
52 photos

I totally agree with Paul, keep it simple. Once you're sailing the model you can't see any difference and no one could care less which way your props turn.

Chas

redpmg23/08/2021 14:09:45
avatar
179 forum posts
17 photos

Been on a Natal Parks Board full size (18ft ) Boat - fitted with twin 75hp outboards - both same rotation - made no difference to performance.

Some big Shark Diving/ Excursion boats here in Gansbaai are fitted with four  300hp outboards - although they usually only run on two. A couple have counter rotating props - most have not.............

So totally agree with Paul & Charles - ignore the rivet counters and keep it simple - makes no difference when running.

Edited By redpmg on 23/08/2021 14:10:41

Ray Wood 223/08/2021 16:44:56
avatar
2546 forum posts
877 photos

Hi All,

Where has the term rivet counter come from with reference to Neil's bait boat ? not actually a model of a boat ?

I'm not aware the DeHavilland Mosquito had any banking issues with the Merlin's both rotating the same direction tricky to keep straight on the ground my father inlaw told me !

Regards Ray

Paul T23/08/2021 17:21:56
avatar
7335 forum posts
1229 photos
2 articles

Ray

The Lancaster was the same as all four props rotated in the same direction.

As for model aircraft I only fit contra rotating props on small electrics.

Paul

Edited By Paul T on 23/08/2021 17:22:47

Colin Bishop23/08/2021 18:36:34
avatar
Moderator
4988 forum posts
6114 photos
412 articles

I rather think that in the model boating world 'rivet counters' have faded away. There are relatively few people now building what might be regarded as traditional 'scratch built' models as there are virually no scale model boating competitions remaining. They have all gone over the last few years.

So people building what might now be termed 'scale replicas' are more than happy to use bought in components, especially those from 3D printing, if it enables them to construct the model they want. And what's not to like really if it enables you to finish your model to a higher standard and more quickly.

Why slave forever over making cowl vents if you can simply purchase the exact versions you want and get on with your model? With no competitions who is to judge what route you take to achieve the result that you want.

Times have changed.

Colin

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Boats? Use our magazine locator link to find your nearest stockist!

Find Model Boats!

Support Our Partners
Nylet
Sarik
Coastal Shipping August 2021
Premier March
SLEC
Restorers Wanted
Pendle Boilers
Shopping Partners
Social Media

'Like' us on Facebook

Follow us on Twitter

Pin us on Pinterest

Member Contributions
Distributors of Model Boats for our overseas readers
Highlights

Make sure you never miss out on the latest news, product reviews and competitions with our free RSS feed

Make your own contribution to the Website

We welcome well written contributions from Website members on almost any aspect of Model Boating with a particular emphasis on practical hints, tips, experience and builds.

In order to maintain a consistent standard and format, all suggestions should first be sent to me by Personal Message for approval in principle. Only a very limited amount of time is available for editing contributions into a suitable format for placing on the website so it is important that the material is well presented, lucid and free from obvious spelling errors. I think it goes without saying that contributions should be illustrated by appropriate photos. I shall be happy to give advice on this.

The Member Contribution area offers space for short informative mini articles which would not normally find a place in Model Boats magazine. It is an opportunity for Website Members to freely share their  expertise and experience but I am afraid that virtue is its own reward as there is no budget to offer more material recompense!

I look forward to receiving your suggestions.

Colin Bishop - Website Editor