Propellor thrust

[Barrie PayneParticipant @barriepayne25068]

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.

[SeasprayParticipant @seaspray]

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.

http://www.amazon.com/Propeller-Handbook-Installing-Understanding-Propellers/dp/0071381767/ref=pd_sim_b_2_img/102-2705441-4429763

This might be of assistance??

[Paul FreshneyParticipant @paulfreshney24971]

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 PayneParticipant @barriepayne25068]

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!!

[SeasprayParticipant @seaspray]

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 SambucettiParticipant @guidosambucetti90794]

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.

Cheers,
GUIDO.

[Barrie PayneParticipant @barriepayne25068]

[Author]

Posts