I have a small lawn in front of my house, which is a rarity in Indian houses. Ranaghat, where I live, is a suburban town in the state of West Bengal in Eastern India. I needed a lawn mower, and found that it would cost me around Rs.5000 (USD 120) to get one from the city. Hence I took recourse of some available machines and material at home and came up with a neat little design of an electric lawn-mower.The cost of the project was slightly less than Rs 1000 (USD 23), much less than what I would have had to spend to buy one.
Step 1: The Blade
Step 2: The Iron Framework
Step 3: The Drill-holder
Step 4: Attaching the Drill-holder
Step 5: Wheels
Step 6: The Electric Drill
This is the lawn mower's engine. Buy any simple electric drill with a long cord that'll lead to a plug point. The drill should be a small one, that'll consume minimum power and will be light. Because cutting grass hardly requires any effort and the iron framework should be able to support the drill. My drill I bought for Rs. 700 (USD 16) and its power consumption is 250 Watts.
Step 7: Assembling
In this short paragraph I'll explain how they fit together to make the lawn mower. So before assembling them you should have all this ready:
A thick bolt, a nut and washer to fit the bolt.
At least 9 sets of nuts-bolts-washers.
The 6 iron rods
The two halves of the holder for the drill
3 wooden wheels
An electric drill
Hammer the ball bearings into the holes on the wooden wheels.
Put together the assembly, joining the pieces by nuts, bolts and washers. This process puts the wheels in place too. Do use washers on both sides of the wheels so that the wooden surfaces of the disks do not rub against the iron rods which hold them in place. Only the washers and the heads of the bolts will make contact with the thick rim of the ball-bearings.
Once this is in place, screw into place the two halves of the drill-holder into the vertical channels. Don't tighten them right now. Place the drill, head down, in the circular space and clamp it tightly in place.
Pass the large bolt through the hole in the blade and tigthen it with a nut and washer. The remaining length of the screw will be held between the three teeth of the drill. So, in place of the drill needle you now have a T-shaped structure, that'll rotate like a propeller when the drill is switched on.
Step 8: Using the Lawn-mower
One thing I haven't described is how to manoeuvre the mower. Well, the best bet is to attach a rope to the horizontal rod (just above and running parallel to the drill-holder), and pull it by the rope. I wouldn't recommend dragging it in circular paths too much,as this would generate twisting forces on the framework and especially the wheels and loosen the joints. But, of course, you can experiment and improve the design further and make it tougher.
See the attached videos :
1. Clamping the drill
2. Attaching the blade
3. Running the drill
4. On grass