by 508medway » Wed Apr 01, 2015 8:36 pm
Sorry to disagree but a scale model to me should have scale props. Warship props of the WW2 era were like the attached photo of George Sitek�s props one of which was used for testing. We have many models in our club and just about all run direct drive. These models can run props up to 78mm plus in size only drawing 3.95 amps in the water when coupled to a decent multi pole motor. Multipole as in 10, 12 poles etc. BTW, by hot, I meant that after 10 minutes of running, the motor was too hot to touch. The Buhlers get warm like all motors do but not to the extent of the Mabuchi�s. I do use some 555s but not with warship style props.
From what he said, Inuit is building a 1/96th scale Baltimore which would be 84.2� long and displace about 44lbs. A 1/72 scale Leander Class cruiser which uses these motors is 92.5� long and displaces about 58lbs. It needs power to get moving and more importnatly, power to stop in a hurry when the inevitable happens and some just turns across your bows.
I have run 2 in a 1/72 scale Leander Frigate for about 15 years now. She wears 50mm 5 blade scale petal props and with the Buhlers is pulling 4.8 amps flat out. With the 555s, she was pulling 6 amps. At 12 volts, that is about 22% more watts (heat!) than the Buhlers. She does run the computer fan cooling system I suggested partly as there is virtually no airflow possible in the long thin hull but mainly because the outside temperature can regularly be in the high 20s C and up to 37 C (100 in degrees F). At 28 degrees, I�ve checked the temperature in her just sitting at her mooring buoy and she has recorded 42 degrees inside. The esc also runs that system to keep it from tripping the thermal cut out built into them.
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Sorry to disagree but a scale model to me should have scale props. Warship props of the WW2 era were like the attached photo of George Sitek�s props one of which was used for testing. We have many models in our club and just about all run direct drive. These models can run props up to 78mm plus in size only drawing 3.95 amps in the water when coupled to a decent multi pole motor. Multipole as in 10, 12 poles etc. BTW, by hot, I meant that after 10 minutes of running, the motor was too hot to touch. The Buhlers get warm like all motors do but not to the extent of the Mabuchi�s. I do use some 555s but not with warship style props.
From what he said, Inuit is building a 1/96th scale Baltimore which would be 84.2� long and displace about 44lbs. A 1/72 scale Leander Class cruiser which uses these motors is 92.5� long and displaces about 58lbs. It needs power to get moving and more importnatly, power to stop in a hurry when the inevitable happens and some just turns across your bows.
I have run 2 in a 1/72 scale Leander Frigate for about 15 years now. She wears 50mm 5 blade scale petal props and with the Buhlers is pulling 4.8 amps flat out. With the 555s, she was pulling 6 amps. At 12 volts, that is about 22% more watts (heat!) than the Buhlers. She does run the computer fan cooling system I suggested partly as there is virtually no airflow possible in the long thin hull but mainly because the outside temperature can regularly be in the high 20s C and up to 37 C (100 in degrees F). At 28 degrees, I�ve checked the temperature in her just sitting at her mooring buoy and she has recorded 42 degrees inside. The esc also runs that system to keep it from tripping the thermal cut out built into them.