Working with my first, "proper" model boat and much enjoying it. Recently converted to brushless (with much help and support from forum members, thank you very much)
I would like to find the optimum prop size and I like the idea of a balanced alloy prop, but don't want to commit to the expense until satisfied about size and pitch. Boat is Dumas Chris Craft 1930 Runabout 36" and my choice is limited by the boat having a 3/16" shaft, currently using a dog drive
While still running the original MFA Torpedo I changed the standard Dumas prop to a Graupner plastic 42X and performance improved significantly.
Yesterday I took delivery of a non-contact tacho and thermometer (£20 the pair)
So today I set out to start learning.
The first lesson was that the female of the species was right, there is, indeed no fool like an old fool, as the attached photo will show.
Motor is Turnigy 3648 1450, 120a ESC, 3s lipo showing 12.6v
I ran it at full throttle for 5 mins with shaft and prop out of water, rpm was steady at 18170 motor temp went up from 25c to 38c
Then, with the assistance of William Shakespeare, I ran it in water for 5mins, rpm was 11900/12000 (fluctuating with my less steady hand and a little movement of the boat) motor temp went to 40c Battery, ESC and Receiver all stayed at 25c no apparent hot spots on cable and battery connections.
One question is, "if the boat had been free to run, would the rpm have risen significantly?
I will be back on the lake tomorrow to give her a more informed run and look at how she handles.
All comments welcome.
