Objective: – To design chopper for composter.

Tools & Material: – Power cutter, GI pipe, iron sheet, welding machine, paint and grinder.

Constructional classification:-

1.length of chopper=130cm

2.wt.of chopper=5kg

3.diameter of chopper=25mm

4.blade lenght=length*width=20cm*11cm

5.blade thickness=0.2mm

6.stroke length=30cm

Design of chopper:-


1.A hallow pipe diameter 25mm & length of chopper is 130 cm taken,cut as per diamension.

2.Blade of chopper iron sheet o.2 mm thick,cut as diamension 20cm*11cm using cutter grinder.

3.Blade was sharp with the help of blade grinder.

4.The groove of 5 cm were made on pipe as well as blade for fixing the blade into the pipe.

5.After the blade fitted into each other & pipe groove.

6.Then blade and pipe welded with welding machine.

7.Then chopper was painted.

Parts of chopper:-

Chopper assembly

  1. Flywheel
  2. Crank
  3. Connecting rod
  4. Chopper
  5. Motor

2. Vessel

3. Supporting system

All the above parts were designed as per dimensions given in table below.

Sr. no.PartsSpecifications
  1.FlywheelDiameter = 30cm
  2.CrankLength = 15 cm
  3.Connecting rodLength = 23.84 cm
  5.VesselVolume = 0.0266 m3 i.e. 26 lit
  6.Supporting system

Material selection:-

Motor selection:-

As the main purpose of development of chopper is to reduce the man power. Power requirement of chopper was 47.12 Watts and calculated torque was 22.50 Nm.

Connecting rod:-

Length of connecting rod was calculated as 23.84 cm. Therefore mild steel plate of width 38.1 mm and thickness 5 mm was selected.  joining these bearing 6301 (inner dia = 12 mm, Outer dia. = 37 mm) was selected.

Now,i replaced connecting rod to half cam.

Problem defination:-

Connecting rod does not get affected as waste does not get chopped and then it can not be used as a fertilizer. So half the cam is going to be used.

Cam design :-

Mechanism of cam:-

Rough diagram of half cam:-

changes in chopper:-

1.firstly connecting rod replace by half cam.

2.Then supporting system & bearing system change by another place.

a)firstly two metel plate cut as per diamension.

b) four drill I made on metal plate with the help of drilling machine.

3. Then supporting system welded with a welding machine,Also bearing system welded with welding machine.

4.Motor and crank is a chain drive that has to be reduced, because the changing of the bearing system has changed, so the chain link will be reduced.