|Barrie Payne||17/06/2007 05:51:00|
8 forum posts
|Can anyone advise me if there is a chart or publication available that indicates the thrust/ speed of available off the shelf props and bow thrusters.|
47 forum posts
|You could go this way but many modellers like myself find that it it a case of suck it and see. My last model, it took an hour and 10 different pitches/diameters of propellers to get the boat running right.|
This might be of assistance??
|Paul Freshney||17/06/2007 22:11:00|
293 forum posts
|Unfortunately the range of propellers is so huge with the proprietory manufacturers like Graupner having a big range and then UK suppliers such as G Sitek and Propshop both offering a massive range of bespoke propellers, it would become virtually impossible to list and detail all of them. These last two advertise regularly in Model Boats and could perhaps advise on the suitability of a particular pBopeller for a particular model. There was a book 'Model boat Propellers' ISBN 0 85242 712 3 printed by Model and Allied Publications (Argus Books Ltd) and revised in 1980, that dealt with the theory, design, selection, scale speeds etc. of model propellers. In other words this book deals with the technical aspects of propelers and the relevant calculations. This book is currently not available in our range, but you might be able to locate a copy on the internet. Price in 1980, was £2.50!|
|Barrie Payne||18/06/2007 08:17:00|
8 forum posts
|Thanks for the responses. Much appreciated.|
However, what I am looking for more specifically is a Bow thruster or ducted fan type of prop that is capble of producing in excess of 250g or 1/2 lb of thrust at as low a speed as possible. The diameter in the region of 50mm. Help!!
47 forum posts
|I still say it is going to be trial and error to get what you require.|
My rule is high speed=large pitch with a motor powerful enough to turn it.The diameter of prop 35mm-45mm/30 inch model is also inportant and you may not have much torque with this setup
Slow speed = small pitch moderate revs probable a largeish prop 45mm-55mm 70 inch model to me this has more torque which is more power/thrust.
Can I enquire what the bow thruster will be used in and the length of model and your motor voltage gearing arrangement.
There are ducted fan books on the aeroplane side of the hobby but I beleive (unless things have changed since my day more like jets nowadays)these had to be high reving glow plug engines.Usaully around the Rossi Engines.
Referring to bow thruster I was reading the other day that a modeller was useing awaterpump with tubes where the bow truster exit was, causeing a good jet of water to turn the boat with very good success.can't remeber where it was or what book
|Guido Sambucetti||15/07/2007 16:23:00|
55 forum posts
|If you are intersted in the book mentioned by Paul Freshney you can find it with Bookfiner.com. There are two copies in the US, price is around five pounds sterling.|
Please login to post a reply.
Want the latest issue of Model Boats? Use our magazine locator link to find your nearest stockist!
Make sure you never miss out on the latest news, product reviews and competitions with our free RSS feed
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