Making a Generator With a 3D Printer, Fan Motor, and Exercise Equipment Transformer

hello.

I am a student who posted a post on the topic of the axial velocity motor project.

This time, I am posting about my experience making a single-phase AC permanent magnet synchronous generator using a fan motor, a transformer, and a 3D printer.

STL file:

https://www.thingiverse.com/thing:6312694

my youtube channel:

https://www.youtube.com/@limsanghong

[Operation video 1 (AC 102V output before improvement)]:

https://youtube.com/shorts/HCFKSTf6rYw?si=pe4Eh3ljo_S3aobo

[Operation video 2 (improved from AC 102V to AC 110V)]:

https://youtu.be/SwKFxbhvg3Q?si=4xnEf7f1SX3RkOU

Materials needed for this project:

1.electric fan motor

2.Shaft 100mm long and 8mm diameter

3.M5 bolt

4.cable tie

5.bearing 806zz

6 M5,M10 tapping screw

There were a lot of unused fan motors left in my storage room.

I thought about converting this into a generator.

First, disassemble the fan motor and take out the stator (square object in the photo) and rotor (round object in the photo).

I checked the status. The stator wires were in good condition, but the problem was with the rotor.

To turn an (induction) motor into a generator, a permanent magnet must be installed on the rotor. The surface of the rotor must be cut to a size suitable for the magnet.

Making the groove was the problem. At first, I thought about cutting it with a grinder, but it was a hassle.

So, I designed a new rotor part and tried to print it out with a 3D printer.

As a result, another problem arose.

Even the size of the fan motor case had to be taken into consideration.

In the end, I decided to redesign the case and print it with a 3D printer.

The designed parts were printed using a 3D printer.

Attach the fan motor stator to the parts printed on a 3D printer.

I secured it with a cable tie.

I also fastened the wires with cable ties and gathered them all together.

Align the magnet with the rotor insertion groove and apply adhesive to attach it.

Attach the stator to the case printed on the printer.

I pulled out the wire separately into the hole on the left side of the case.

Then attach the magnet to the rotor pulled out by the printer with a glue gun.

It was mounted so that it was centered on the stator.

The stator was fastened on both sides with M5 bolts.

Make a thread in the hole on the bottom of the case with an M10 tapping screw.

The front and back of the case

Make a thread using an M5 tapping screw.

Install the back case cover part by tightening it with M5 bolts.

Install the Keas front cover by tightening it with M5 bolts.

This completes assembly.

and,

When rotating the generator shaft at high speed by attaching it to the drill chuck,

Output on each of the four wires (separately pulled from the hole on the left side of the case)

Single-phase AC voltage was measured.

If a rectifier circuit is created here, the output from the generator

Converts AC voltage to DC voltage to operate home electronic devices.

I can do it

I made AC 220V with this generator once and

Instead of building a rectifier circuit,

The transformer taken out of the broken exercise equipment is used as a booster.

I decided to make AC220V instead.

Here, the word booster refers to converting low voltage to high voltage.

It is an electrical device that boosts voltage.

And in the picture, the white wire is the primary winding wire and the rest are

The wire is a secondary winding wire. The configuration of the transformer is,

To determine the turns ratio of the transformer

The resistance of each wire was measured with a multimeter.

Formula used to calculate transformer turns ratio

After measurement, the result was like this. From here to the transformer secondary winding

Since only the red wire is used, the turns ratio is determined by the resistance value measured on the red wire.

Calculated.

The result came out like this...

In the end, this generator could not produce AC220V.

When I actually operated it, AC 102.3V was measured.

The calculated and measured values ​​are roughly similar.

I measured the output waveform with an oscilloscope.

The sine waveform is a bit distorted, and the output waveform is a bit distorted.

It's unstable.