ScannerStrap

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This page is a development stub. Please enhance this page by adding information, cad files, nice big images, and well structured data!

//work in progress.


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ScannerStrap

Release status: experimental

Front-complete web.jpg
Description Documenting a 3D printer made from a used large format flatbed scanner
License GPL
Author 63alfred
Contributors
Based-on WolfStrap
Categories RepStrap, Wood, XY-head
CAD Models
External Link Google+


Contents

Discussion

Original sketch of 3D printer concept.

Building a 3D printer from used $60 US flatbed scanner.

MICROTEK ScanMake 9600XL, large format flatbed scanner. Used, purchased at REPC for $60 in Seattle. This will be used for the bases of the 3D Printer I am building. Primary advantage, this scanner has two scanner slide assemblies, bed and lid, complete with stepper motors, belt drive, dual slide rails. Thus, mounted in the appropriately fabricated superstructure, these components can form the primary basis for the x and y axis for the printer.

MICROTEK ScanMaker 9600LX
MICROTEK ScanMaker 9600LX

X and Y Axis

Disassembled top and bottom of scanner and tore out the guts to get at the slide mechanisms.

Bottom (Y-axis) removed from scanner
Top (X-axis) removed from scanner
Left over innards from scanner

Maximum length and width of printer set by travel of bottom and lid of original scanner. This will determine the size of the wooden superstructure for the printer.

Gross travel capabilities of Y and X axis

Scanner Stepper Motors

The stepper motor from the bottom of the scanner. Y-axis, is a TECO, TYPE 4H4018X1603, 5V, 1A, Holding Torque-1.2Kg-cm (Bi-POLAR) X-axis, is a TECO, TYPE 4H4018X0101, 12V, 0.23A, Holding Torque-0.8Kg-cm (Uni-POLAR)

Y axis stepper motor
X axis stepper motor

These smaller stepper motors are probably too small, especially the Uni-POLAR one from the top of the scanner (x-axis) so new ones might be in order(from MakeFarm). The small Bi-POLAR stepper motor from the bottom of the scanner (y-axis) was replaced by a larger one. To make use of the same belt and gear assembly that came with the bottom of the scanner for the Y-axis, some modification of the steel scanner body was required. Hacksaws are always useful with this soft steel. for the X-axis the Bi-POLAR stepper motor form the bottom of the scanner was moved into what is now the X-axis. This motor may still be too small but will try it in this location first as replacing this motor with a larger one would physically take some major modifications to the existing metal assembly. Let's see if it will work first before we embark on this. This motor was definitely too small for the heavier Y-axis, hopefully it will be just enough for the X-axis.

New Y-axis Stepper
New Y-axis Stepper
Replaced X-axis Stepper

Stabilization and Alignment of Y-axis

This is done by tying the bottom carriage of the old scanner with its associated belt movement to the wood assembly using 1/4" threaded rod cut in half and secured to the outer 2x4 and the metal carriage in two places. This not only serves to stabilize the bottom but the double-nut assembly allows fine tuning later to ensure that the rails of the Y-axis travel in a direction perpendicular to the travel of the X-axis.

Stabilizing Y-axis outside view
Stabilizing Y-axis inside view
Double-nut fine tuning for Y-axis alignment

Wood Superstructure

Wood superstructure constructed of 2X4s with a bottom of 3/4" plywood. X-axis from the scanner is mounted in the vertical stand. The Y-axis sets in the bottom of the structure. Both bottom and lid slide systems have only one bushing connected to the rail. This is fine for the the Y-axis because gravity is your friend here. For the X-axis mounted in the vertical a nylon stay was glued to the unattached rail to secure it.

Crude Superstructure, front
Crude Superstructure, back
Nylon stay to secure second rail

Completed Structure Before Z-axis installed

Approximate build area, Y-axis - 17 inches (432 mm), X-axis - 11 inches (280 mm), Z-axis - 10 inches (254 mm)

Z-axis configuration
Z-axis configuration

Work Platform

Mounted directly to aluminum carriage assembly with 3/8" x 3" fully threaded bolts. CARB compliant 1/2" birch plywood (soy-based instead of urea-formaldhyde glue) is used for lower and upper work platform. With the upper work platform to have a heated bed I did not want any toxic fumes emitted at these higher temperatures.

Initial work platform sketch.
3/8" x 3" bolts mounted to Y-axis scanner carriage.
3/4" plywood base. Required to lift work platform above Y-axis carriage obstructions.
Bottom work platform mounting.
Top mounting platform with glass surface form top of scanner.
Full assembly with Y-axis complete.
1/2” Birch plywood, CARB P-2 Compliant NAF Soy-based glue

Z-axis

Z-axis will have to be fabricated independent of original scanner. First, a piece of 3/4" plywood was fabricated to mount the X-axis rail system. Z-axis will slide along a center mounted drawer slide (Rockler Center drawer slide, $8.49) . Z-axis stepper motor will be mounted to the top of the drawer slide and the extruder assembly will be mounted to the bottom. Both will be attached to opposite ends of a 3/8 threaded rod. Rotation of the Z-axis stepper motor will move it, the center rail of the drawer slide, and the extruder assembly up and down.

Z-axis configuration

Z-axis Stepper Motor Coupling

Fabrication of coupler between 5 mm stepper motor (from MakeFarm) shaft and 3/8" threaded rod. The idea is to use a traditional 3/8" threaded coupling to connect to the the rod being used for the z-axis. The opposite end of the coupling will have to be modified so that it can accept the 5 mm stepper shaft. Insert to make this transition has to be as centered as possible to prevent wobble. A 5/16" tension pin was chosen for this. The tension pin is made of hardened steel which made its use difficult, but it did match the stepper shaft well. The stepper shaft is secured to the coupler by a 8-32 set screw that is drilled and tapped in. All hardware parts purchased at local Ace Hardware and Lowes stores.

Drilling coupling for set screw.
Tapping coupling for set screw.
5/16" tension pin
5/16" tension pin excess filed off.
Completed modified coupling with set screw installed

Stepper motor was attached to the inner slide of the drawer slide that is used for the Z-axis with a small L-bracket from some old furniture assembly parts. The stepper shaft is them attached to the modified 3/8" threaded rod coupler and secured using the installed 8-32 set screw.

Mounting bracket for Z-axis stepper motor connection to inner slide of drawer slide used for this axis.
Final Z-axis stepper motor assembly.
Final Z-axis stepper motor assembly.

Mounting Extruder to Z-axis

Greg's hinged extruder and hot end (from MakeFarm) is secured to the bottom of the Z-axis via a fabricated wooden bracket that is attached to the threaded rod (with a bearing secured by lock nuts) and the inner slide of the drawer slide. The bearing is glued to the wooden bracket with epoxy. The wooden bracket is secured to the inner slide with a wood screw. Completed assembly by adding Gold Kapton Tape Polyamide High Temp 1/4" (6mm) x 36yds to hot end.

Mounting bracket for extruder sketch.
Mounting bracket prior to extruder mounting.
Mounted Greg's hinged extruder.

Fully assembled bottom bracket of Z-axis.

Mounted Greg's hinged extruder.
Final fully assembled Z-axis.
Kapton tape added to hot end.

When fully extended the large weight at the bottom of the inner drawer slide (Rockler Center drawer slide, $7.99) of the Z-axis caused too much of a wobble in the Y direction. To stabilize this another drawer slide (modified slightly with a hammer) was mounted to the top of the outer drawer slide of the Z-axis and the cross beam 2x4 running parallel to the X-axis. This slide allowed movement of the Z-axis in the X direction along with stabilizing it in the X direction.

Second drawer slide stabilizing Y wobble of the Z-axis.

Electronics

Mounting of Heated Bed

Mounting of the heating plate on plywood working surface and covered with glass plate originally from large format scanner.

Heatbed wired up
Cutout to on bed to accomodate heatbed wiring and thermistor
Mounted heatbed wiring
Mounted heatbed from top
Assembled working surface
Fully assembled with heated bed
Leveling springs for bed

PrintrBoard and Power Supply

Addition of PrintrBoard and Power Supply

PrintrBoard wired up
Full System Hooked up