Transcript:
I am back with another video of a ducted fan, which has a high thrust to push things away and powerful enough to pull my hand. It is a complete DIY project, So let’s start. The project is started with the CAD model of the ducted fan. This cad model is designed for dual propeller. All the files can be downloaded from the links in the description. I had 3d printed all the parts with a layer height of 0.2 mm to begin the assembly of the single propeller Ducted fan. We require an outer casing to mount all the parts on it, A nozzle to increase the velocity of the exhaust air 100 mm ducted fan with a set of 12 blades on it and a diffuser on which I have already mounted the screws, I am using 1000kv brushless motor and connecting the motor to the outer casing with the help of 4 m3 screws of size 16mm All the part links are provided in the description. The propeller is attached to the motor with the help of a bullet connector. Make sure the bullet connector is of the perfect size. The thickness of the propeller and the bullet connector is different. Then you can use a plastic washer to mount them. Then the bullet connector is placed on the brushless motor and it is tightened with the help of a plier. The nozzle is placed at the back of the casing and it is fitted perfectly with the help of the grooves provided to match the alignment of the nozzle in the outer casing. It is mounted with the help of four screws. [MUSIC] The diffuser is placed at the top of the propeller and it is tightened with the help of a screwdriver. After the final assembly. The fan will look like this. For thus calculation. We need a sliding mechanism on which our fan can slide for that. I am connecting 2. Lm8w bearings and securing them with the help of zip ties. [MUSIC] For making a slider, I’m using two smooth rods of 8mm dial and 500 mm length and two 3d printed mount since there is a loose fit between the smooth rods and the mount. So I am using electrical tape to hold them in places before attaching the second mount. I have inserted the fan on the smooth rod and then attached the second. Mount as I am sliding the fan on the smooth rods. I can feel a bit of a resistance between the smooth rods and the bearing. It’s because there is a misalignment between the bearing and the rod. So let us check if the fence lights in this condition, so I am connecting the motor with a 30 M cse and an 11.1 Volt Lipo battery. I have connected a servo tester with the ESC to give the throttle so we can see the fan is moving forward and as the resistance is high, so it’s taking the frame along with it. Friction here is creating a lots of thrust drag. So let’s test for one more time. [MUSIC] [Music] And since I can’t see any change, so I have to modify the frame. [MUSIC] So I have replaced the two bearing with a set of four so that the fan does not wobble during the test and also corrected the alignment of the bearing and the rod. So let’s start the test and before proceeding, wear your safety glasses bearing just popped out because of vibration, and we can see the thrust is enough to lift the fan in a slant position, but no matter how much we reduce the resistance, there will always be some thrust drag because of the rod and the wearing, so I have a very simple way to calculate the thrust of the fan. So first we check the weight of the fan, which is about 161 gram Now I have kept two wooden block on the weighing scale and attach them with the tape so that it doesn’t move because of the vibration of the fan. Now I have connected the motor to the ESC and place the fan upside down on the two block and reset the weighing scale to zero after increasing the throttle. I slightly hold the fence so that it doesn’t fall off the weighing scale. We have to keep in mind of certain limitations. First is ducted trend uses a high KV motor, but here we can’t use that to prevent the breaking of propeller because of high centrifugal force and second is air intake restriction because of weighing scale and block. The maximum thrust was 323 gram at 90 throttle, which was a better result for this type of fan. Now we begin with the assembly of a dual propeller ducted fan for this. We need an extra propeller. An extra motor and a center part. I disassembled the nozzle from the outer casing and attached another motor at the back of previous motor with the help of some screws After mounting the back motor, the front propeller is attached and then tighten with a plier. Then the central casing is attached with the outer casing and attached with the help of four screws and guys. If you don’t have a 3d printer, then you can go and watch my DIY 3d printer video and make one for you. After mounting the central casing, The back propeller is attached with the back motor with the help of bullet connector. Make sure that the orientation of the back propeller and front propeller is different, then mount the nozzle with the central casing, followed by two diffuser [Music] [Music] after the final assembly. The fan will look like this. Now, connect both the ACS with motors and make sure the connection is such that both the motors push the air in backward direction. If any motor direction is different, then just reverse any two wires of it. Now we connect the battery to check it thrust and it’s working perfectly fine and at fifty percent throttle, It’s pulling my hand. You all can’t see, but I can feel its high thrust. [MUSIC] So for the thrust test? I am following the same procedure as the previous one. [MUSIC] Its weight is 278 gram [Music] and during the thrust test, the back propeller came off is because of the vibrations caused by the propeller, So let’s reattach the propeller by removing the nozzle and tightening it. And if you guys have any ducted fan design and wants to check his thrust test, then you can mail me the design and I will do the thrust test for you and upload the result, And if you guys haven’t watched my previous video of electric jet engine, then you can go and have a look. [MUSIC] [Music] [Music] so let’s connect the battery for the Thrust Test [Music] [Music] [Music]. This dual propeller Ducted fan has a very high airflow rate and gives us a thrust of 609 gram at 90 throttle. Which is very good for this type of ducted fan, and we have to keep in mind. All the limitations first is that the commercial ducted fan uses a very high KV motor, but we are using a 1000 KV motor. Second is the air intake. There is a air resistance which is caused by the scale. If it would have been suspended freely, then it would have given us a thrust of approx 800 to 900 gram. As you can see, it has a high thrust. I have one more way to show you. It’s power! [MUSIC] So let’s check if it can push out 585 gram water bottle and it can easily push the water bottle at 50 throttle, So let’s move to Level 2. Now. Here is the 953 gram water bottle. [MUSIC] [Applause] and it takes 80 percent of the throttle to push the water bottle. So at last we have designed a high thrust, high efficiency and a good weight to thrust ratio. Ducted fan and guys just subscribe this channel because my each video is the upgradation of my previous project.