Gardeners and farmers can save their backs and plant seeds without stooping over when they use this handmade seed planter. Thai rice farmers had a hand in the design, but it could be used with other seeds.

The seeder is built from low-cost materials - mostly PVC pipe and bamboo. And, if you have them, you can use power tools to make it, but hand tools, including a machete, will work fine, too.

A team from Drexel University in Philadelphia, Pennsylvania is developing the seeder with rice farmers in Bo Klua, a community in rural Thailand. They've partnered with a local Thai organization called the Sustainable Development Research Foundation and produced a construction guide in English and Thai.

Both versions are available for free download.
English manual

Alex Moseson, a sustainable development engineer and an assistant teaching professor at Drexel who heads the project, has asked Instructables and E4C users for ideas and tips on how to improve it. He would also like to see people modify the design to suit their own farming and gardening needs.

As such, Moseson gave the seeder a Creative Commons Attribution-Non-Commercial license.

For more on the seeder and the project in Bo Klua, please see the Drexel team's site.

Step 1: Materials

These are the materials in each part and we'll show how to make the parts.

Materials
Handle: PVC or bamboo
Slide pipe: PVC
Diverter: Wood or bamboo
Spear: Metal rod
Funnel: Wood or bamboo
Chute: Sheet metal
Slant chute block: Wood or bamboo
Flat Chute block: Wood or bamboo
Stopper: PVC
Reinforcement ring: PVC
Screw, rubberband

Tools
Tape measure
Pencil or marker
Screwdriver
Files
Hammer
Hacksaw
Sheet metal shears
Pliers

Optional tools
Vice, angle grinder, power drill and a machete

Step 2: What It Looks Like

In this series you see the exploded view, the planting mechanism from four different angles, a cut-away view of the seed "counter" inside the mechanism and the last image shows the spring loader in action.

Now to make the parts...

Step 3: Handle

Each step corresponds to a photo in order:
1. Measure handle material to person height
2. Draw cross lines to make first window at (1.8 cm, 3 cm). Draw cross lines for second window at (4 cm, 7cm)
3. Measure and draw outside lines ( 2 cm apart)
4. Drill holes inside the edges of the area to be removed
5. Use utility knife and hammer to remove doorway pieces
6. Smooth doorway edges with file
7. You're finished.

On to the slide pipe...

Step 4: Slide Pipe

1. Measure slide pipe material to length (25cm)
2. Cut slide pipe material to mark
3. Measure and draw outside lines (2cm apart)
4. Draw cross lines to make first window at (3.5 cm, 7.5 cm). Draw cross lines for second window at (4 cm, 7 cm)
5. Mark line on side opposite doorways for track (6.5 cm)
6. Drill holes inside the edges of the area to be removed for doorways
7. Drill relief holes along line to be removed for track
8. Use utility knife and hammer to remove doorway pieces
9. Use utility knife and hammer to remove bulk material
10. Smooth doorway edges with file
11. Smooth slot edges with file
12. You're finished.

On to the diverter...

Step 5: Diverter

1. Hone wood or bamboo to tightly fit inside the handle
2. Cut at a 45° angle. If using bamboo, make cut above a notch.
3. If using bamboo, make plug to fit in hole above notch
4. Put plug in hole and cut to 45° line.
5. File to fit tight in the handle and tight around the spear
6. You're finished.

Now, on to the spear...

Step 6: Spear

1. Measure the end of the metal to find the center point
2. Measure the length to grind for the point (3cm)
3. Grind one end to make a blunted point around the center point. You can use a grinder or a hack saw.
4. Measure to length (11cm)
5. Cut to length
6. You're finished.

Now, on to the funnel...

Step 7: Funnel

1. Hone the wood (or bamboo) to tightly fit inside the slide pipe
2. Measure it to make sure it's 3cm
3. Cut it to length
4. Drill a hole through the center if you're using wood.
5. Carve the slope of the funnel
6. Carve hole to be able fit spear
7. File to fit tight in slide pipe and loose around spear
8. You're finished.

On to the chute...

Step 8: Chute

1. Draw the layout on flat sheet metal 17.5cm x (1 cm, 1.5 cm, 2 cm, 1.5 cm, 1 cm)
2. Cut out the sheet metal
3. Bend the cut metal into shape
4. You're finished.

Now you're on to the slanted chute block...

Step 9: Slanted Chute Block

1. Draw square dimensions of the chute on a flat surface of wood or bamboo (2 cm)
2. Cut the wood or bamboo along the lines
3. Measure to length on both sides of a 45° angle ( 2 cm on top, 4 cm on bottom)
4. Cut the chute block to length at a 45° angle
5. File to fit it in chute
6. You're finished

On to the flat chute block...

Step 10: Flat Chute Block

1. Draw square dimensions of the chute on a flat surface of wood or bamboo (2 cm)
2. Cut the wood or bamboo along the lines
3. Measure to length (2 cm)
4. Cut the chute block to length
5. File it to fit in chute
6. You're finished

On to the stopper...

Step 11: Stopper

1. Measure it to length (2 cm)
2. Cut it to length
3. File the inside edge smooth
4. You're finished

On to the reinforcement ring...

Step 12: Reinforcement Ring

1. Measure it to length (5 cm)
2. Cut it to length
3. Slit it along its length
4. File the inside edge smooth
5. You're finished

Now to assemble all of the parts...

Step 13: Assembly

1. Assemble the spear in the diverter in the handle
2. Drill a hole through the handle, diverter and spear but not throught ot the other side of the handle
3. File the edge of the drilled hole on the handle to sink a screw head in the handle
4. Insert a screw through the entire device
5. Cut off the screw tip sticking out
6. Measure the dimensions for the chamber on the handle
7. Gouge out the chamber with a chisel, making sure it holds the amount of seeds or rice desired for each actuation
8. Gouge out the area below the chamber to let the seeds drop more easily
9. Insert the funnel into the slide pipe
10. Drill two holes through slide pipe into funnel, but not into other side of funnel
11. Insert 2 short screws through slide pipe into funnel
12. Measure the height to put the chute blocks in the chute
13. Drill a hole for each of the three chute blocks
14. Screw center slanted chute block into chute with short screw
15. Screw bottom slanted chute block and top flat chute block into chute using long screw
16. Mark the 2 long screws sticking into slide pipe, remove and cut the screws
17. Insert handle all the way into slide pipe such that the handle contacts the funnel and the windows line up
18. Mark a line 0.2 cm down from the top edge of the top window
19. Line up the mark with the bottom edge of the bottom window
20. Drill out a hole in the handle at the bottom of the track
21. Drive the screw into the hole so that it sticks out 1cm
22. Mark the handle at the top edge of the slide pipe
23. Slide the slide pipe down and mark the handle 0.1 cm down from the last mark
24. Screw in stopper with bottom edge on the lower mark using a small screw
25. Glue the reinforcing ring on slide pipe flush with the top of the slide pipe
26. Remove the screw from the handle and the slide pipe from around the handle
27. Drive a short screw into the reinforcing ring 1 cm down from the top in line with the slot so that it sticks out 1 cm
28. Remove screw and cut off the excess that stuck into the slide pipe
29. Replace the screw in the hole
30. Replace the chute on the slide pipe and screw into place
31. Put the slide pipe around the handle and replace the screw in the slot
32. Wrap rubber band around the two screw and pull tight
33. Wrap the wire around the rubber band and cut the excess
34. Cut the excess rubber band
35. Fill the handle with rice
36. Place a PVC cap or a cloth with rubber band on the end as a cap
37. All done!