Build instructions for 4 Axis Controller

Below you will find build instructions for the P4AC 4 axis controller.  This board uses four Pololu 1201 modules to drive steppers for CNC operations.  The control connector is a 40-pin cable that beaks out to four separate 10-pin connectors for use with reprap/makerbot electronics.  The kit comes with everything needed to assemble the controller board.  The instructions below assume some prior soldering experience.  If you have not soldered anything before, please read this tutorial and acquaint yourself with proper soldering techniques and safety precautions.  

I have kits available.  Contact me at the address below if you are interested in one.

If you have questions, please email me at lj.johnyang*AT*gmail*DOT*com

Bill of Materials (BOM)
 Component ID
 Detail Manufacturer part number
 R1, R4, R5, R8, R9, R12, R13, R16, R17, R18, R19
 1k Ohm 1/4 watt 5% (brown-black-red-gold) (11)
 R2, R7, R11, R15 10k Ohm 1/4 watt 5% (brown-black-orange-gold) (4)
 R3, R6, R10, R14 100k Ohm 1/4 watt 5% (brown-black-yellow-gold) (4)
 100uF electrolytic capacitor
 Led (not labeled on silkscreen) 3mm red Led (21)
 Power Molex disk drive power connector
 Min, Max vertical cdrom connector (8) 70543-0038
 CONTROL shrouded 40-pin header for IDC cable 30340-6002HB
 Stepper 0.156" friction lock male header
 MS selectors 2x3 6 pin 0.1" pin male header (4)
 Jumper 0.1" shunt jumper (quantity 12)
 Motor, Logic
 2x 32-socket 0.1" female header
 A axis aux control 4-pin header 929974-01-04
 Pololu Pololu 1201 A4983 stepper motor driver carrier
 Heatsink heatsink for chip on pololu driver 

Gather all the parts together 

Solder the four 10k Ohm resistors (brown-black-orange-gold).

Solder the four 100K Ohm resistors (brown-black-yellow-gold)

Solder the eleven 1k Ohm resistors (brown-black-red-gold)

Solder the twenty-one LEDs.  LEDs are polarized and must be inserted correctly.  The long leg of the LED is the positive lead and should go in the hole on the side marked with the positive (+) sign.  If you have red and green LEDs, place the green LEDs on the outer two locations for each stepper location.

Solder the 40-pin shrouded connector.  Be careful to align the keyhole in the part with the notch in the silkscreen.  Solder one pin in one corner and ensure the connector is correctly positioned and straight before proceeding to solder all 39 other pins.  It is easier to remelt the one pin and align the connector than it is to heat all 40 pins to adjust the way it sits.

Solder the microstep selection jumper blocks.  If you have 1x3 pin strips, insert them into the jumpers to hold them straight and aligned so that the jumper will fit after you solder them in place.  If you have a 2x3 header, you do not have to worry about the alignment of the pins.

Solder in a 4-pin header to the aux A axis control connectors.  You can use male or female headers.  I have chosen male pins here, but you can use female headers if you prefer.  The choice depends on the kind of jumper wire you have to use if you will be using this connector.

Insert the two 32-pin female headers and solder them in.  You may want to insert a pololu 1201 while you solder the headers in place to ensure that the modules will fit.  If you do not insert a module while you solder, you will want to solder one pin then flip the board over and make sure the headers are vertical and not leaning such that the pololu modules cannot be inserted later.

Insert the 4-pin stepper connectors.  Solder one pin and make sure the connector is vertical before soldering the rest of the pins on that connector.  Repeat for all the stepper connectors.

Solder in the power connector.  You will want to make sure the angled corners on the connector match the lines on the silkscreen.  Solder one pin and make sure the connector is straight before continuing to solder the rest of the pins.

Solder in the electrolytic capacitor.  This capacitor is polarized so be careful to align the positive leg  (the longer one) with the positive (+) sign on the silkscreen.  The negative side of the capacitor is marked with a white bar as well.

If you are going to be using mechanical endstops, insert the headers in the locations you need.  Be careful to match up the key of the connector with the matching shape in the silkscreen.  In this example I have populated the XMin, YMin and ZMin locations.  Again, solder one pin and ensure the connector is straight before finishing to solder the rest of the pins.  

This completes the assembly of the 4 axis controller.  Next you will have to insert the pololu 1201 modules in the correct locations.  Once those are in place, insert the 40-pin cable into the board and attach the 10-pin cables to your reprap/makerbot motherboard.  The mounting holes on the board match the holes used to attach the stepper controllers on a makerbot, so you can attach the board to one of the locations on the side of a makerbot.

Here is a picture of the board with the pololu units installed and in use.

If you have questions, please email me at lj.johnyang*AT*gmail*DOT*com