PrusaBuildNotesBraino

Prof Braino's Prusa Build Log

Summary: To catch my build notes for my Prusa Build Autumn 2011

High level project is to implement an alternative processor, specifically the Parallax Propeller per this discussion http://forums.parallax.com/showthread.php?129448-Prop-based-CNC-3D-printer

In order to establish a baseline as to what constitutes the current 3D-Printer (as of 20110701), I opted to build a unit for comparison. I settled on a modified Mendel Prusa http://reprap.org/wiki/Prusa. This includes a modified Wades extruder, and LM88uu linear bearings. The X-axis ends are different. Some parts are MDF instead of printed.

This is a log of the specifics I encountered. The brick and mortar locations are in the Chicago Northwest Suburbs.

The total price was estimated to be $300-$400 USD. The actual prices are listed for each item. So far the total is: $638! Don't tell my wife!

The additional costs were due to the pre-built kits for hot end and motherboard.

I'm not do good with electronics (I'm more of a software guy), and saved my self at least a couple weeks with the solidoodle part.

The hot end was another spot of trouble. I did manage to find a very nice scape of PEEK, and couple sources for nichrome wire, but did not happen across Telfon rod yet.

Mechanical

Printed parts from Sacha at Pumping Station One http://pumpingstationone.org/tag/reprap/ This kit includes all the printed parts. The vertices are replaces by MDF pieces in this kit, that are very precise and are quicker to make. There might be one peice missing from Sacha's kit, the wooden plate for the modified Wades' extruder. Be sure to ask if you go this route.

$150

Rods from McMaster-Carr (they delivered to my door!)

$78

Fasterners from Jordan Supply (there's more than listed on the web site) http://www.jordanindustrial.com/

$11

Hot End

MakerGear - the instructions are not organized clearly. I made some major mistakes despite reading them first several times, and following quite closely.

http://www.makergear.com/products/operators-pack "Operator pack" and "Hot End Pack" and (there was third term) all refer to the assembly that holds the heater coil and extruder tip. It cost $75

The Hot End pack requires Wooden Mounting Pieces - Wade for $6.00 USD.

The wooden mounting plates did not fit the modified Wades extruder directly. (the screw holes were off by about 2mm). I don't know if there is and alternate wooden plate with the correct dimensions, perhaps Sacha laser cut his own and forgot to include them in the kit of parts he sells?

$86 including shipping

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Electronics

I opted for a one piece mainboard

http://reprap.org/wiki/Sanguinololu

This one is preassembled

http://store.solidoodle.com/index.php?route=product/product&path=63&product_id=52

It includes a bootloader pre-burned during assembly and testing during production.

This needed a two pin shunt header soldered to the AUTO RST labeled on the skilk screen to enable Autoreset. Shunting the jumper allows the PC to restart the Arduino for programming, etc. Removing the shunt (default) allow the unit to operate stand alone; that is, it will not reboot when the unit is disconnected or reconnected to the PC print.

This module is intended to be swapped out and replaced with the propeller chip implementation at some point.

$116 including shipping

Stepper Motors and Drivers

Pololu 1200 were recommended by several sources. FIVE are needed, two for the Z-axis. Reordering one more motor costs nearly double the price of the motor due to shipping.

http://www.pololu.com/catalog/product/1200/faqs

The stepper drivers are refered to by the stepper driver IC. The unit we buy is the IC mounted on a carried board. The A4988 has over current protection. FOUR are needed. The one used for the Z-axis can drive the two Z-motors easily. New notes say to wire them in series instead of parallel contraindicating the instructions.

http://www.pololu.com/catalog/product/1182

$161 including shipping (would have been $11 less had it been a single order)

Belts and Pulleys

These we a bit of trouble to find. The instructions specify T5 belts and 11 tooth cog for 5mm shaft.

I ended up getting a 9 foot length of T5 belt and have enough left over to replace one axis.

The 11 tooth pulleys are for 1/4 inch and 3/16 inch belt. I had to drill them out to 5mm to fit on the Pololu motor shafts.

McMaster Carr 5710k12 (2) 7959k24 (9 feet)

$36

Power Supply, Connectors, harversted parts

Power Supply

I found a pre-ATX power supply in the junk box. This type uses a physical power switch instead of control by motherboard logic. Its a HIPRO Hp-200PPGN harvested from a Tiger Direct K-6/2. It was diagnosed as unstable, but claims 8 amps on the 12 volt rail.

Connectors

The sanguino board has 11 connectors for the motors, end stops, and thermistors.

The four 4 pins stepper motor connectors are the same size as 1.44 floppy drive connectors. I harvested these from dead power supplies and Y-cables. Cots $0

The three 3 pin endstop connectors are the same as size as PC fan connectors (with RPM monitoring). I harvested these from noise fans recovered from dead PCs. The yellow and black wires were swapped compared to the layout on the Sanguino. This was fixed with a toothpick and a magnifying glass.

The four 2 pin thermistor and heater connectors for the extruderr and heated bed are the same as PC fan connectors (without RPM monitoring). I don't have a heated bed at this time, so it was easy to find 2 dead fans.

Software

The firmware selected for the printer affects the software needed for the PC. After selecting and extracting the firmware archive, we discover what prerequisite software is needed on the PC. This is why the printe firmware is listed first, but appears in the middle of the PC software install list.

Firmware

SPRINTER archive https://github.com/kliment/Sprinter

PC

The PC software needs to be set up to run interface to the Arduino firmware.

I selected the first Recommended firmware from http://reprap.org/wiki/Sanguinololu#Software * SPRINTER *

The software needs to be set up on the PC before the firmware will respond.

The software might not need to be installed in this exact order, but do it this way to be safe.

Windows XP workstation:

• Needs Python 2.7.2

http://www.python.org/download/releases/2.7.2/ I used http://www.python.org/ftp/python/2.7.2/python-2.7.2.msi

• Needs Python wx

http://www.wxpython.org/download.php#stable I used http://downloads.sourceforge.net/wxpython/wxPython2.8-win32-unicode-2.8.12.1-py27.exe

Download and extract the SPRINTER archive https://github.com/kliment/Sprinter

Follow the instructions in the SPRINTER README

• Arduino IDE http://www.arduino.cc/en/Main/Software

I used current newest version 0023

• Sanguino configuration files, version 0018

http://sanguino.cc/softwareforwindows

EDIT the files as directed