Stepper Parts List

for basic circuit diagram (printed circuit board calls for different parts list - see the pcb webpage):

from Radio Shack:
a. (8) TIP-120 transistors
b. (8) heat sinks for above
c. (8) 1/4W 470 ohm resistors
d. (8) 2.5A 100 V PIV diodes
e. (4) 1/4W 220 ohm resistors
f. (2) 74LS04 hex inverters
g. (1) large instrument box
h. (1) 276-160 circuit board
i. (1) 25-pin cable
j. (1) 25-pin connector kit
k. (2) 9-pin connector kits
l. (4) momentary push buttons - normally off, temporarily on
m. (1) 3-way center-off switch
n. (1) 2-way switch
o. (1) package of small diodes
p. (2) IC 14 pin sockets
q. (1) 7805 power regulator chip
r. (1) heat sink for above
s. (3) 0.1 uF capacitors
from a local well stocked electronics store:
a. (4) 30V 5W zerner diodes
 

gear reducer:

from a motions control outfit such as:
Torque Transmissions (TorqueTran@aol.com, (http://www.torquetrans.com)1-216-352-8995) (60:1, use final roller reduction of 40:1) or
Allied Devices (100:1, use final roller reduction of 24:1) (1-516-223-9100) or
Andy Saulietis' hard plastic gear reducers (iss@pvtnetworks.net) or
Larry Myers' Byers gears (http://www.mountaininstruments.com or larrym@foothill.net) or
American Science and Surplus (http://www.sciplus.com/) look for motors with gear heads for ~$5 removing the motor or
Martin Sprockets (http://www.martinsprocket.com/contact.htm)
Harmonic Drives (http://www.harmonicdrive.net/)
RS-Components worldwide (http://www.rs-components.com/)
Arrick Robotics (http://www.robotics.com/pr23.html)
Andantex's cycloidal differentials (http://www.andantex.com/dls.html)
Small Parts Co (http://www.smartparts.com)


1 gear reducer per axis ~$100 (aim for gear reducer multiplied by final roller reduction to equal about 2400:1, this gives 1/4 arcsecond per microstep, exact microstep size is entered in the CONFIG.DAT file)

2 stepper motors:

Jameco Electronics 
Oriental Motors (the 400 step motors are very nice)
Surplus stocks are a moving target!  Look for steppers at surplus houses
a. (2) stepper motors: 6-12 VDC .3 to 1 amp/phase 20+ in-oz torque ($2+ and approx 2"x2"x2" size with 1/4" shafts), preferably 6 leads, but 5 or 8 lead motors will do, 4 lead motors are bipolar motors and not suitable, preferably 200 steps per revolution (1.8 deg full step size)

b. (2) cables: Jameco DB9 M-F 6' connector 25700 $4.95 + Jameco DB9M connector 15747 $.35 + 15721 hood $.32, 

c. LED test unit: Jameco 152856 LEDs for winding testers $.12 + Jameco DB9M connector 15747 $.35 + 36 470 ohm resistor Jameco 31165 $.89/100

1 bipolar stepper motor:

 Jameco 237472 or MPJA's four lead bipolar stepper - only needs to have minimal holding torque to operate focusers and field de-rotators

servo motors:

Pittman Motors from clickautomation.com

servo controllers:

PIC Servo controller by Kerr, available from Jameco Co #184989 $180, RS232->RS485 converter #184971 $60

2 encoders:

part number S2-2500-B from US Digital, seller of Hewlett-Packard encoders

The optional MC3479 field derotator chip which replaces the discontinued SAA1042 can be ordered from Jameco Electronics, part number 25216 (MC3469P), price $5.