Step 1: Go Get Stuff
(x2) servos modified for direct drive**
(x1) telephone handset
(x1) 4 x AA battery holder
(x1) DPDT lever switch
(x2) 6" bolts
(x2) 5" bolts
(x4) bolt covers
(x2) thin 1" nut and bolt
(x1) a couple dozen assorted zip ties
(x1) print template (download below)
**Modify your servos for direct drive here
Step 2: Open It Up
Step 3: Drill
Essentially, you should drill the holes in such a way that they create a square on the backside of each opening.
Step 4: The First Motor
Insert the first motor into the handset opening that is on the opposite side of the jack, in such a way that the horn is facing inwards.
(The horn is the gear-like object attached to the servo shaft)
Step 5: The Second Motor
Zip tie them both in place using the holes that you have drilled in Step 3.
Step 6: Switch
There should probably a small lip, upon which the switch can sit.
Make certain that the lever of the switch is pointing upwards (towards the gear on the motor).
Step 7: Template
Cut out around the circumference of the two large circles.
Step 8: Cut the CDs
For the two large outer holes, drill 1/4" holes (or whatever is appropriate for your 5" and 6" bolts).
For the four smaller inner holes, drill 1/8" holes (or whatever is appropriate for your thinnest zip ties).
On the one CD with the outer notch, cut this shape out of the CD using a pair of general-purpose scissors.
Step 9: Battery Holder
Bolt the battery holder onto the handset with your pair of 1" nuts and bolts.
Step 10: Wire It Up
Solder two short wires such that an "X" is formed between the outer terminals of the switch. Basically, the back left would be connected to the front right and the front left to the back right. This causes power to be applied backwards when the switch is flipped.
Solder together the red wire from motor 1 with the black wire from motor 2 and the black from motor 1 with the red from motor 2 (which motor is designated to be which is unimportant).
Lastly, solder the red and black wire pairs to either set of outer terminals. For instance, solder one pair to the back left terminal and the other pair to the back right terminal.
If all of this sounds really confusing, just check the wiring diagram below.
Step 11: Attach CDs
Zip tie the CDs to the motors in such a way that the motor is at the center of its rotation point and the two outer holes are perpendicular to the handset.
Also, keep in mind that the outer notch was cut to allow the switch lever to stick through.
Step 12: Bolt
Pass the longer bolts through the other CD.
Fasten all of them in place with nuts.
Step 13: Bolt Covers
Step 14: Power!
Insert batteries, and then let it go.