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Arch-Ball Clock: Build Your Own |
As featured in the July 2009 issue of Nuts
and Volts Magazine
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| Downloads: |
Download the full size patterns for the three arches.
Hours Arch
Minutes Arch
Large Arch
Code
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| Make the Arches: |
- Print and cut out the arch patterns downloaded earlier.
- Use spray glue to attach the patterns to 1/2 inch medium Density fiberboard (MDF).
- Cut the wood almost to the pattern line and then sand to line. Make sure that the inner portion of the hour and minute arches are smooth and nick free as the ball bearings need to roll freely.
- Cut two 2"x3-3/4" pieces of MDF for the feet at the end of the large arch.
- Cut a groove on the inside of the hour and minutes arches leaving a track for the balls to ride on. The balls do not ride inside the groove but on the outer rim.
- For mounting the hour and minutes arches drill a hole that will allow for a tight press-fit onto the motor shaft.
- Cut out a recess in the large arch for the stepper motor to sit in. This allows the motor shaft to stick through far enough to allow the the
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Electronics Parts List:
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| Part #
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Description
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Supplier
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Supplier Catalog #
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| IC1 |
Picaxe 18x - pre-programmed |
*** see note below |
ABC-IC1 |
| R1 |
Resistor 22k, 1/4 w |
www.Jameco.com |
691180 |
| R2, R8 |
Resistor 10k, 1/4 w |
www.Jameco.com |
691104 |
| R3 - R6 |
Resistor 4k7, 1/4 w |
www.Jameco.com |
691024 |
| R7 |
Resistor 2k2, 1/4 w |
www.Jameco.com |
690945 |
| R9 - R16 |
Resistor 1k, 1/4 w |
www.Jameco.com |
690865 |
| C1 |
2200 mfd, 26 v radial capacitor |
www.Jameco.com |
30535 |
| C2 |
.01 mfd capacitor |
www.Jameco.com |
15229 |
| D1 - D12 |
1N4007 diode |
www.Jameco.com |
36012 |
| Q1 - Q9 |
MPS222A transistor |
www.Jameco.com |
210673 |
| VR1 |
LM340T-5 Voltage Regulator |
www.Jameco.com |
51262 |
| VR2 |
LM340T-12 Voltage Regulator |
www.Jameco.com |
51334< |
| S1 |
SPDT on-off-on switch |
www.Jameco.com |
75889 |
| S2, S3 |
Push button |
www.Jameco.com |
1586074 |
| StpM1, StpM2 |
Stepper Motor 42BYG016 |
www.Jameco.com |
224022 |
| Qty |
Description |
Supplier |
Supplier Catalog # |
| 1 |
Printed Circuit Board |
*** see note below |
ABC-PCB |
| 1 |
18 pin IC socket (for IC1) |
www.Jameco.com |
38113 |
| 1 |
12 VAC, 1500 ma wall wart |
www.Jameco.com |
167151 |
| 2 |
Heat sinks (for Vr1, VR2) |
www.Jameco.com |
42622 |
| 2 |
4-40 screw, lock washer, nut (for VR1, VR2 & heat sinks) |
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**** Printed circuit board and programmed Picaxe 18x
microcontroller are available from: Nuts and Volts
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Assemble the Circuit Board: |
The circuit board is mounted between the two motors on the back side of the large arch
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Setting the time:
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Setting the time is a four step process. Steps 1 and 2 "zero" the motors while steps 3 and 4 actually set the current time.
- Flip S1 to the hour position. Press S2 and S3 to position the hour arch so the ball bearing is sitting at the '1' position.
- Flip S1 to the minute position. Press S2 and S3 to position the minute arch so the ball bearing is sitting at the '0' position.
- Flip S1 to the center position. Press S3 to set the hour position to the current time.
Press S2 to set the minute position to the current time.
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Please Note:
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After a power outage, and/or the time hasn't been properly set, the ball bearing may roll off the end of the arches and fall to the floor. Causing a choking hazard to small children and pets.
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