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Archive for February, 2015
Posted by bigtruck169 | Feb 23, 2015 @ 03:23 PM | 17,360 Views - some cheap kit boat - drive shaft set

Creating a solid mount for the motor is imperative. Attach wood to the inside of the hull with epoxy and mount your motor mount to the wood. Be warned that the plastic hulls are generally on the thin side and will have a good amount of give to them. This is another reason to use wood to stiffen the area where the motor mounts. Don't be surprised if there is some slight "twisting" of the hull when the motor is fully torqued.
When getting a rudder, it is possible to get a rudder with a built in water pick-up for the cooling system. When using these, it is very important to get the prop as close as possible to the rudder. The prop wash is what forces the water through the tubing. No prop wash, no flow. The forward motion of the boat is NOT enough to move the water through the tubes. (Learned that one the hard way


Posted by bigtruck169 | Feb 17, 2015 @ 11:28 AM | 19,089 Views
1 hp = 746 Watts.
EDF - 85% exhaust reduction Fan swept area( FSA)
you want it the exact same size as the rear of the edf tube, but in a normal configuration, you could vary the size of the opening depending on what speed you want more thrust at... a smaller opening will give less initial thrust, but will give more thrust when the plane is up to speed, allowing a higher top speed, where a larger opening will give more initial thrust, but will give less thrust once the plane is up to speed, meaning a lower top speed....
FSA caluclater -

Micro EDF Jets and Power Systems

the longer the inlet duct, the larger the inlet area should be. a good compromise would be an 85% FSA inlet, with an 85% FSA exhaust area. as a rule of thumb, you should never go smaller on the inlet, than the exhaust are

Intake area depends on the complexity of the internal ducting. corsair Nut had and F86 with an intake area roughly 70% of FSA and it performed very well. With a straight duct, smaller intake.area will work well. In complex shaped duct, I doubt that intake area would have worked as well.

Having said that, try to aim.for an intake area between 85% and 100% of your fans FSA. This will give you the beas performance overall. The smaller the intake area, the faster your top end speed will be, but static performance will be lower.

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