I love the design. And I have a garden outside the town. My goal was to make a cheap cutter for grass from the parts that I have. The result was better than I expected.

UPDATE:

Instruction for the head with a nylon trimmer line look in step 12.

Step 1: Parts and Tools

Parts what you need:

8x 3d printed parts

1x Motor

3x Blades for Heavy-Duty Cutter

1x Battery or power supply

1x 5.5 mm DC power socket and plug

1x Button

1x Round wooden plank

5x M4 mm Lock Nut

5x M4x16

9x M4 washers

4x M3 mm Nut

2x M3x15 mm screw for shield

2x M3x10 mm screw for blade holder

2x M3x6 mm screw for motor

2x M3x20 mm screw for button box

4-6x Wood screws

Some wire

Some zip ties

Tools:

Screwdriver

Drills 3&4 mm for cleaning holes

Iron solder

Hot glue gun or other glue for DC power socket

Plier

For the Grass Cutter I use motor R540-6530 6V 10000RPM, blades 18 mm wide and 0.5 mm thick, round wooden plank dia. 32 mm, old 6V battery from electric car for kids. Weight of 3d printed parts of about 150 grams.

Step 2: Preparing Motor

Pass a wire through the hole in the lid of the motor box. Then solder a wire to the motor.

Step 3: Assembling Box for the Motor

Attach to the box for motor the holder of handle, then attach the shield holder. Insert into the holes M4 screws and tighten the lock nuts. Place the motor into the box and tighten the M3x6 screws.

Step 4: Finishing Assemble Box for the Motor

Place the M3 nuts in the blades holder and slightly tighten the M3x10 screws. Then install the blades holder on the motor shaft and tighten the screws. Close the lid on the box for the engine.

Step 5: Attaching Parts to a Wooden Plank

Attach the box with motor to a wooden plank and tighten 2-4 screws for wood. Then attach the button base to the wooden plank and tighten screws.

Step 6: Assembling the Button Box

Сut the earth leg on DC power socket. Then measure the length of wire and cut off the excess. Insert the power button into hole. Solder a wires to the button and the DC power socket. Then glue the DC power socket to the button box. Attach the button box to button base and tighten M3x20 screws. Attach a wire to wooden plank with zip ties.

Step 7: Attaching the Shield

Attach the shield to the shield holder and insert the M3x15 screws into holes. Then tighten the M3 nuts on back side.

Step 8: Assembling the Blades

Cut the blades to the required size. Insert the M4 lock nuts in the blade holder. Then put the M4 washer on the M4 screw, then the blade in the direction of rotation of the engine, and then put on another 2 M4 washers. Tighten the M4 screw in the blade holder. Repeat 2 more times. Then a little loosen the M4 screws so that the blade can easily rotate on screws.

Step 9: Enjoy

Congratulations. Grass cutter is ready for use.

Step 10: My First Test and Solving the Problem

The first test revealed a problem with the design of the blade holder. During work the grass twirling on the motor shaft. After changing the design problem disappeared. The latest version of the parts added to the project.

Step 11: Excellent Results of the Work

The latest version of the grass cutter is working without any problems. Engine power enough to cut thick grass stalks.

Thank you for watching.

PS. If anyone wants to make remix of any parts I add links to youmagine and thingiverse

https://www.youmagine.com/designs/grass-cutter-tri...

http://www.thingiverse.com/thing:1647726

Step 12: Head for Nylon Trimmer Line

Trimmer working with nylon trimmer line but for it need more powerful motor and different wire connector for more current. I think a motor RS-550 20000 RPM from old cordless drill will be nice.

Parts:

3x 3d printed parts (2 for head and 1 for button box)

2x M3x8 screw

2x M3x15 screw

1x M3x18 screw

2x M3 wide washers

5x M3 nuts

Some nylon trimmer line dia. 2-3 mm