Rod Logic 1-bit Full Adder in LEGO - The Half-Baked Maker

Rod Logic 1-bit Full Adder
in LEGO
v1.0 – 13 Dec 2009
halfbakedmaker.org

5x
2
3
2x 7
12x 9
48x
4x
4x
17x
Parts List
11
13
15
46x
70x
222x
10x
24x
Perpendicular Axle Joiner
Axle Pin with Friction
Pin with Friction
Long Pin with Friction
Bush
Of the length 15 beams, try to
get 3 in a bright color, 7 in a
different bright color, and 2 in a
third bright color.
The best place to get the specific LEGO pieces you want is bricklink.com. The
most common colors are black, light gray, and dark gray.
Get extras!

Subassembly:
Small Side Wall
(build 4)

Subassembly:
Large Side Wall
(build 4)

Turn it around for
the next step.

2x
Short Side Wall
Subassembly:
Module
(build 2)

Axle pins on top, regular
pins on the bottom.

2x
Long Side Wall

1x
Module
Subassembly:
2x1 Module
(build 1)

Axle pin here and
on the back side.

1x
Module

Pins here and on
the back side.

Beam here and on
the back side.

Subassembly:
Input Rod A
(build 1)

Axle pin
Axle pin

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free 1. Connector
2. Stop bush 2. Empty
3. Empty 3. Empty
4. Empty 4. 0 •
5. 0 5. 1
6. 1 • 6. 0 •
7. 0 7. 1
8. 1 • 8. 0
9. 0 • 9. 1 •
10. 1 10. Not used (0)
11. 0 • 11. Not used (1)
12. 1 12. Empty
13. Empty 13. Empty
14. Empty 14. Stop bush
15. Connector 15. Free

Subassembly:
Input Rod B
(build 1)

Axle pin
Axle pin

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free 1. Connector
2. Stop bush 2. Empty
3. Empty 3. Empty
4. Empty 4. 0 •
5. 0 5. 1
6. 1 • 6. 0
7. 0 • 7. 1 •
8. 1 8. 0 •
9. 0 9. 1
10. 1 • 10. Not used (0)
11. 0 • 11. Not used (1)
12. 1 12. Empty
13. Empty 13. Empty
14. Empty 14. Stop bush
15. Connector 15. Free

Subassembly:
Input Rod Cin
(build 1)

Axle pin
Axle pin

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free 1. Connector
2. Stop bush 2. Empty
3. Empty 3. Empty
4. Empty 4. 0
5. 0 • 5. 1 •
6. 1 6. 0 •
7. 0 7. 1
8. 1 • 8. 0 •
9. 0 9. 1
10. 1 • 10. Not used (0)
11. 0 • 11. Not used (1)
12. 1 12. Empty
13. Empty 13. Empty
14. Empty 14. Stop bush
15. Connector 15. Free

Subassembly:
Intermediate Rod for S
(build 3)

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free
2. Stop bush
3. Empty
4. Empty
5. 0 (top) • sense (bottom) •
6. 1 (top)
7. 0 (top) sense (bottom) •
8. 1 (top)
9. 0 (top) sense (bottom) •
10. 1 (top)
11. Not used
12. Not used
13. Empty
14. Stop bush
15. Free

Subassembly:
Intermediate Rod for
S/Cout
(build 1)

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free
2. Stop bush
3. Empty
4. Empty
5. 0 (top) • sense (bottom) •
6. 1 (top)
7. 0 (top) • sense (bottom) •
8. 1 (top)
9. 0 (top) sense (bottom) •
10. 1 (top)
11. Not used
12. Not used
13. Empty
14. Stop bush
15. Free

Subassembly:
Intermediate Rod for Cout
(build 3)

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free
2. Stop bush
3. Empty
4. Empty
5. 0 (top) sense (bottom) •
6. 1 (top)
7. 0 (top) • sense (bottom) •
8. 1 (top)
9. 0 (top) sense (bottom) •
10. 1 (top)
11. Not used
12. Not used
13. Empty
14. Stop bush
15. Free

Subassembly:
Output Rod
(build 2)

This is the end to
push. You could
mark it with
another bush.
The pin positions determine the logic! From
left to right, the function of each hole is:
1. Free 1. Connector
2. Stop bush 2. Empty
3. Empty 3. Empty
4. Empty 4. sense •
5. sense • 5. Empty
6. Empty 6. sense •
7. sense • 7. Empty
8. Empty 8. sense •
9. sense • 9. Empty
10. Empty 10. Not used
11. sense • 11. Not used
12. Empty 12. Empty
13. Empty 13. Empty
14. Empty 14. Stop bush
15. Connector 15. Free

Subassembly:
Short Side Stop
(build 4)

Subassembly:
Long Side Stop
(build 4)

1x
2x1 Module
Main Assembly:
Full Adder

1x
Input Rod A
The ends to push go on
this side.

1x
Input Rod B

1x
Input Rod Cin

2x
Short Side
Stop
You might find it easier to install
these if you first remove the stop
bushes from the rods.

3x
Intermediate Rod
for S
The ends to push go on
this side.

1x
Intermediate Rod
for S/Cout

3x
Intermediate Rod
for Cout

4x
Long Side
Stop
You might find it easier to install
these if you first remove the stop
bushes from the rods.
Double-check the logic now! Check that
each intermediate rod can be pushed only
if its input combination is set.

2x
The ends to push go on
this side.
Output Rod

2x
Short Side
Stop