I designed this nacelle for my VQ Models Hornet to eliminate the terrible pitching it has with throttle. The original thrust line causes the plane to drope the nose sharply when throttle is increased, and vice versa. This nacelle points the efflux up (effectively down thrust) which compensates for the high thrust line and makes the plane fly great.
Here’s a flight video with this nacelle and motor:
It’s designed to use this motor with a 4S battery: https://www.ebay.com/itm/JMT-70mm-3500KV-Brushless-Motor-for-RC-Airplane-6-Blades-EDF-Unit-Ducted-Fan/142493692168
It will draw 95 A with a 4S battery on full throttle, and will cruise the plane fine on half thtottle. It does not overheat. I use a 4S 4000 mAh lipo.
Use short pieces of 4 mm rod to join the EDF housing together. The exhaust piece must point upwards, off course.
Print Fanhousing01 from ASA, ABS or PETG or other heat resistant material to prevent it from deforming from motor heat.
The coolingfan part can be used on the end of the motor if it gets hot. The recommended motor usually doesn’t get hot.
Dynamically balance the impeller using aluminum tape on the blades. Run up the motor with the impeller to low throttle settings and feel for vibrations. Add tape and try again. Repeat until you find the imbalance, until it spins without vibrations.
The batterytray part is a raised part for mounting the battery with velcro straps in the nose.
The Noseretractmount part is a spacer for mounting retracts in the nose.
-This is a very highly loaded assembly at high speed so it’s important that you know what you are doing.
-Make sure the integrity of the printed impeller is good before trying to run it.
-Always wear protective glasses when test runnin the fan. Always protect your eyes.
-Do NOT run the fan at high power while holding in your hand.
-Keep your hands and any loose items away from the fan when running. It WILL shred your fingers if they get sucked in, and the suction force is very strong. If something gets sucked in it can damage the impeller and potentially shatter, throwing loose debris out.
3D printing settings
Print the housing of the nacelle with two perimeters ands six top and bottom layers and 0% infill.
Print Fanhousing01 solid.
Print the impeller with four perimeters and eight top and bottom layers and 0% infill