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THIS
PROCEDURE WILL HELP YOU CONSTRUCT A PRINTER CAPABLE OF PRINTING IN 3
DIMENSIONS. |
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| WARNINGS:
THE
CHEMICAL USED IN THIS SYNTHESIS IS DANGEROUS. FUMES
CAN BE CAUSTIC IF INHALED. OBSERVE
ALL SAFETY PRECAUTIONS OUTLINED BY THE MANUFACTURER. ALSO,
AS DESCRIBED THERE ARE SOME EXPOSED ELECTRICAL CONNECTIONS. DO
NOT TOUCH THE EXPOSED ELECTRONICS, AND DISCONNECT POWER ANY TIME YOU
TOUCH THE DEVICE. |
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DESCRIPTION
RAPID
PROTOTYPING, OR THE CONVERSION OF COMPUTER MODELS DIRECTLY INTO SOLID
OBJECTS, IS A RELATIVELY NEW AND SIGNIFICANT TOOL IN THE ENGINEERING OR
DESIGN INDUSTRY. VARIOUS METHODS OF RAPID PROTOTYPING
("RP" OR "3D PRINTING") EXIST, SOME EVEN ABLE TO
CREATE STRUCTURES IN A VARIETY OF MATERIALS, EVEN METALS. THIS
DOCUMENT WILL HELP YOU CONVERT AN ORDINARY INKJET PRINTER INTO A 3D
PRINTER.
THE
GENERAL NATURE OF 3D PRINTERS IS TO PRINT AN OBJECT IN LAYERS, USUALLY
BY COMBINING TWO CHEMICALS WHICH FORM A HARD 'SLICE' OF THE
OBJECT. SOME SPRAY ADHESIVE ONTO A POWDER, OTHERS HARDEN A LIQUID
CHEMICAL WITH A LASER. THE PRINTER PRESENTED HERE WILL HARDER A
LAYER BY INTRODUCING TWO LIQUID CHEMICALS. IN ALL 3D PRINTERS,
ONCE A LAYER IS HARDENED, THE NEXT LAYER IS DEPOSITED ON TOP AND THE TWO
BOND TOGETHER. THIS CONSTRUCTION TECHNIQUE MAKES IT POSSIBLE TO
ASSEMBLE OBJECTS THAT ARE IMPOSSIBLE TO BUILD ANY OTHER WAY.
BEARINGS AND SHAFTS CAN BE BUILT ALREADY ASSEMBLED, AND GEAR BOXES
PRINTED OUT IN ONE STEP.
THIS
DEVICE WILL MODIFY A COMMON (CHEAP) INKJET PRINTER SUCH THAT IT WILL BE
ABLE TO FEED ITSELF BACK AND FORTH OVER A CHAMBER OF THE BUILD
MATERIAL. LAYERS WILL BE CREATED BY SPRAYING THE COMMON INKJET INK
ONTO A POOL OF SUPERGLUE THAT HARDENS ON CONTACT WITH THE INK. WHEN
A LAYER IS COMPLETE, THE PRINTER WILL RETURN ITSELF TO THE STARTING
POSITION, AND LOWER THE JUST-PRINTED LAYER INTO THE BASIN SO THAT THE
NEXT LAYER CAN BE ADDED.
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MATERIALS |
-LEXMARK z25 PRINTER
-OR-
-BUY MODIFIED Z25 FROM SCI-SPOT.COM STORE
-WOOD
(1" X .5" X 12' FURRING STRIPS WORK WELL)
-SMALL PLASTIC
CONTAINER (3" X 3" X 1")
-LARGE SPRING (1" DIA.,
2" LONG, COMPRESSION, SMALL k)
-2" BOLT AND NUT
-BRASS TUBE (BOLT MUST FIT CLOSELY INSIDE)
-2' OF
1/8" BRASS ROD
-MISCELLANEOUS 'JUNK BOX' ITEMS
-LOTS OF SUPERGLUE / CYANOACRYLATE GLUE (HOBBY STORE)
-WIRING HARNESS
-2 DPDT MINI LEVER SWITCHES
-4PDT 12V RELAY
-20' WIRE
-OR-
-BUY 'WIRING HARNESS' FROM SCI-SPOT.COM STORE |
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EQUIPMENT
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-SOLDERING IRON
-LARGE
CLAMP(S) |
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PROCEDURE |
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WHY?
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NOTE: I HAD CAREFULLY DOCUMENTED EVERY
STEP OF THIS PROCEDURE, HOWEVER SOME OF THE IMAGES WERE LOST WHEN I
ACCIDENTALLY BURNED OUT THE FIRST PRINTER (EPSON). I'VE TRIED TO
RETAKE MANY OF THE PICTURES, BUT SOME COULDN'T BE TAKEN IN A
'DISASSEMBLED' STATE. SORRY.
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1. GET
YOUR Z25 AND REMOVE ALL THE EXTERNAL CASING. BASICALLY THIS IS
EVERYTHING WHITE. DO NOT MESS WITH THE LARGEST BLUE BOTTOM
PIECE... YET. |
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IT IS HIGHLY LIKELY THAT YOU'LL NEVER PUT
THESE BACK ON, HOWEVER YOU CAN SAVE THEM TO MAKE YOUR PRINTER A LITTLE
PRETTIER WHEN YOU'RE ALL DONE.
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2.
THIS MIGHT BE A LITTLE TOUGH. YOU'LL NEED TO CUT AWAY A LOT OF THE
BLUE PLASTIC REINFORCEMENTS ON THE BOTTOM OF THE PRINTER, AS WELL AS ALL
THE PLASTIC DIRECTLY BELOW THE PRINT HEAD, AND ALSO A LARGE CHUNK FROM
THE LOWER REAR WALL. THE CUTS YOU MAKE IN THE REAR WALL WILL
BECOME WHAT POSITIONS YOUR PRINTER ON IT'S TRACK, SO KEEP IN MIND HOW
WIDE YOU WANT YOUR BUILD BASIN TO BE. OR JUST USE THE DIMENSIONS
GIVEN BELOW. DISCARD THE FORWARD MOST PAPER ROLLER. |
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THE PLASTIC NEEDS TO BE CUT AWAY SO THAT THE
PAPER FEED ROLLER CAN CONTACT THE GROUND. THIS ALLOWS THE PRINTER TO
MOVE ITSELF, INSTEAD OF JUST THE PAPER. BE CAREFUL WITH THESE CUTS,
YOU WANT THE CUTS YOU MAKE BELOW THE PRINT HEAD TO BE EXACTLY AS WIDE AS
THE ONES YOU MAKE IN THE REAR WALL. I KNOW THAT'S CONFUSING, SEE THE
PICTURE (IGNORE THE 'EXTRA'S ON THE PRINTER IN THE PICTURES. WE'LL
GET TO THOSE)
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3.
NOW YOU'LL NEED TO BUILD A 'BASE'. THE BASE WILL BE A SET OF
ELEVATED RAILS THAT THE PRINTER CAN DRIVE BACK AND FORTH ALONG.
THE BASIN WHERE THE MODEL IS BUILT RESTS BETWEEN THE RAILS.
CONSTRUCT THIS AS YOU LIKE, 12 FOOT SECTIONS OF FURRING STRIP (1" X
.5") SEEM TO BE A GOOD CHOICE. NOTE THAT I MADE MINE TOO LONG
BECAUSE I STARTED WITH A MUCH DIFFERENT PLAN. SAMPLE DIMENSIONS
ARE BELOW. |
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THIS IS SELF EXPLANATORY. BUILD THE
BASE ANYWAY YOU LIKE. JUST MAKE THE RAILS WIDE ENOUGH THAT THEY
NEARLY TOUCH THE EDGES OF THE CUTS YOU MADE IN THE PRINTER. THIS
ENSURE THAT THE PRINTER STAYS 'STRAIGHT'. MAKE SURE ITS NOT A TIGHT
FIT; THE PRINTER DOESN'T HAVE FANTASTIC TRACTION.
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4.
YOU'LL NEED TO REMOVE THE PRINTER'S MAIN BOARD FOR THIS STEP. GO
AHEAD AND DISCONNECT ALL THE WIRES THAT ATTACH TO THE BOARD; WE'LL BE
MESSING WITH THEM IN A SECOND AS WELL. ONCE THE BOARD IS FREE, IN
THE BOTTOM RIGHT CORNER IS A BLACK PHOTOINTERRUPTER THAT LOOKS LIKE A
'U'.
YOU NEED TO DESOLDER IT, WHICH IS A BIG PAIN IN THE ASS. USE A 15
WATT IRON OR YOU MAY BURN OUT THE BOARD (ALTHOUGH LEXMARK BOARDS SEEM TO
BE QUITE TOUGH). I DIDN'T HAVE ANY DESOLDERING TOOLS SO I DID IT
LIKE THIS: HEAT BOTH OF THE PINS ON ONE SIDE AT THE SAME
TIME. WHILE HEATING, APPLY STRONG PRESSURE ON THE OTHER SIDE OF
THE BOARD, IN A DIRECTION THAT WILL 'ROCK' THE THING OFF THE BOARD WHEN
THE SOLDER MELTS. REPEAT THIS FOR THE OTHER SIDE, AND BACK AND
FORTH A BUNCH OF TIMES TILL IT ROCKS OUT.
NOW, IF YOU'RE LIKE ME, YOURE GOING TO BREAK A LEAD OR TWO OFF THE
PHOTOINTERRUPTER. I BROKE THEM ALL OFF. MORE ON THIS LATER.
SOLDER 4 LONG (2') WIRES TO THE TRACES WHERE YOU REMOVED THE
COMPONENT. THESE MUST BE ABLE TO REACH THE OTHER SIDE OF THE GAP
YOU CUT IN THE BACK WALL, WHERE THAT SENSOR IS GOING TO LIVE.
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THE MOST DIFFICULT PART OF THIS PROJECT IS
THE PRINTER'S VARIOUS SENSORY MECHANISMS. PRINTERS IN GENERAL HATE
BEING OUT OF CONTACT WITH ANY OF THEIR PARTS, ESPECIALLY THEIR PAPER FEED
SYSTEM. MOVING THIS SENSOR WILL ALLOW US TO TRICK THE PRINTER INTO
THINKING IT HAS LOADED A PIECE OF PAPER WHILE ITS OVER THE BASIN.
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5.
SOLDER THE SENSOR ONTO THE FOUR WIRES YOU JUST SOLDERED TO THE
BOARD. BE SURE TO KEEP TRACK OF WHICH WIRE WENT TO WHICH CORNER OF
THE SENSOR.
NOW, YOU PROBABLY BROKE THE LEADS OFF THE SENSOR WHEN YOU DESOLDERED
IT. NO PROBLEM. YOU CAN USE YOUR SOLDERING IRON TO MELT OFF
SOME OF THE CASE NEAR THE BROKEN LEAD. ONCE YOU HAVE A BIT MORE
EXPOSED YOU CAN SOLDER TO IT. IN EXTREME CASES, LIKE MINE, YOU CAN
TAKE A DREMEL TOOL AND VERY CAREFULLY SAND DOWN THE SIDES OF THE
COMPONENT UNTIL THE LEADS ARE EXPOSED.
WHEN YOU'VE ATTACHED THE SENSOR, GLUE IT TO THE BOTTOM EDGE OF THE REAR
GAP AS SHOWN. |
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DUH.
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6.
NOW FIND THE RIBBON CABLE FROM THE MOTOR THAT DRIVES THE PAPER FEED, AND
CUT IT IN HALF. PLUG THE FREE BIT OF THE CABLE INTO THE BOARD, AND
THEN EXTEND BOTH ENDS OF THE CABLE BY SOLDERING 9" WIRES TO EACH OF
THE EIGHT LEADS. |
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THE DRIVE STEPPER NEEDS TO BE MODIFIED SUCH
THAT IT CAN PULL THE PRINTER FORWARD WHILE PRINTER, BUT ALSO REVERSE TO
PUT IT BACK TO THE STARTING POSITION. WE WILL DO THIS BY
INTERCEPTING THE DRIVING PULSES AND REARRANGING THEM.
TO BE MORE PRECISE, THIS IS A BIPOLAR STEPPER, WHICH CONSISTS OF TWO COILS
SURROUNDING A PERMANENT MAGNET ROTOR. REVERSING THE WIRES TO ONE OF
THE COILS WILL CAUSE THE STEPPER TO ROTATE IN THE OPPOSITE DIRECTION.
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7. AT
THIS POINT THE WIRING HARNESS SHOULD BE CONSTRUCTED AS SHOWN IN THE
SCHEMATIC BELOW, OR IF YOU PURCHASED ONE (THANKS) SIMPLY INSTALL IT AS
PER THE INCLUDED INSTRUCTIONS. REMEMBER THAT WIRES 1 AND 2 (THE
BLACK WIRE IS NUMBER 1) NEED TO BE CONNECTED TO THE RELAY. WIRES 3
AND 4 CAN BE CONNECTED TO THE CORRESPONDING WIRE 3 AND 4 GOING TO THE
BOARD. |
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THE WIRING HARNESS IS A LATCHING RELAY THAT
REVERSES THE POLARITY OF THE STEPPER COIL. THE SWITCHES LATCH AND
UNLATCH THE RELAY. NOTE THAT I
BUILT MY WIRING HARNESS A LITTLE DIFFERENTLY BECAUSE I HADN'T THOUGHT IT
THROUGH VERY WELL. DON'T FOLLOW THE PICTURES TOO CLOSELY FOR THIS
REASON (I USED TWO ADDITIONAL RELAYS TO ACT AS THE LATCH.. DOH!).
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8.
NOW THE BASIN ITSELF MUST BE CONSTRUCTED. FIND A SMALL PLASTIC
CONTAINER THAT FITS WELL BETWEEN THE RAILS. DRILL A HOLE IN THE
BOTTOM LARGE ENOUGH FOR THE BRASS TUBE TO PASS THROUGH. EPOXY A
SHORT LENGTH OF THE TUBE IN PLACE. I ADDED A PIECE OF RUBBER FOR
STABILITY. |
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THE BOLT WILL SERVE AS THE MOVEABLE PLATFORM
THAT THE OBJECT IS BUILT UPON. THE BRASS TUBE KEEPS THE BOLT FROM
MOVING AROUND, SINCE IT MUST BE VERY STILL IF EACH LAYER IS TO LINE UP
CORRECTLY.
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9. USE
THE BRASS ROD AND SOME INGENUITY TO CREATE A SET OF 4 SPOKES FOR THE
NUT. I USED SUPER GLUE, CHECK THE PICTURE IF YOU'RE UNCLEAR.
THE BOTTOM OF THE BRASS TUBE SHOULD BE SURROUNDED WITH A CROWN; A RING
WITH FOUR GENTLY SLOPED VERTICAL POINTS. THIS IS EASILY MADE FORM
A LARGE PLASTIC BOTTLE CAP. THE LARGER THE DIAMETER, THE
BETTER.
IN THE PICTURE I'M USING A LARGE PLASTIC RING FROM A DESK ON CAMPUS (SHHH). |
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THE CROWN IS ABSOLUTELY CRITICAL. AS
THE NUTS ADVANCES ON THE BOLT TO LOWER THE PLATFORM, THE CROWN WILL CAUSE
IT TO MOMENTARILY PULL FARTHER DOWNWARDS. THIS DUNKS THE MODEL INTO
THE BUILDING MEDIUM, SO THAT THE TOP IS WELL COATED AND THE NEXT LAYER CAN
ADHERE.
USE AS LARGE A CROWN AS IS PRACTICAL. THE LARGE DIAMETER HELPS KEEP
THE POINTS FROM BECOMING TOO STEEP. STEEP POINTS WOULD ALLOW THE
SPRING TO SLAM THE PLATFORM BACK UP, POSSIBLY SPLASHING THE BUILD
MATERIAL.
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10. NOW
INSTALL THE BASIN INTO THE RAILS. YOU CAN SEE I ADDED SOME EXTRA CROSS MEMBERS
TO EASE GLUING.
ALSO, ADD TO THE RAILS A STRIP OF SOME
OPAQUE MATERIAL WHICH WILL SLIDE INTO THE SENSOR THAT YOU JUST GLUED TO
THE SIDE OF THE PRINTER'S REAR WALL.
FINALLY, ADD A PIECE OF MATERIAL WHICH
CAN FLEX TOWARD THE END OF THE RAILS (AS SHOWN IN PICTURE), BUT DOES NOT
COLLAPSE UNDER PRESSURE PUSHING IT TOWARDS THE RAIL. I USED A LITTLE
PIECE OF BRASS, WITH A LITTLE BIT OF RUBBER AS A STOPPER.
REFER TO DIAGRAMS BELOW FOR DIMENSIONS.
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THE STRIP OF MATERIAL IS TO BLOCK THE BEAM
INSIDE THE SENSOR YOU GLUED TO THE SIDE OF THE PRINTER. THIS IS THE
SENSOR THAT DETECTS PAPER UNDER THE PRINT HEAD. WHEN THE BEAM IS
BLOCKED, THERE IS NO PAPER PRESENT.
THE STRIP OF METAL ON THE OTHER SIDE WILL
TRIP A SWITCH ON THE PRINTER THAT REVERSES THE MOTOR DIRECTION.
HOWEVER, SINCE IT CAN BEND OUT OF THE WAY TOWARDS THE BACK OF THE PRINTER,
IT WILL ONLY TRIGGER THE SWITCH WHEN THE PRINTER IS MOVING
FORWARD. THIS IS CRITICAL.
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11. ATTACH
THE SWITCH ON THE WIRING HARNESS WITH THE BLACK WIRES AS SHOWN IN THE
PICTURE. BE SURE THAT IT TRIGGERS JUST WHEN THE PHOTOINTERRUPTER
LEAVES THE RAIL ON THE OTHER SIDE.
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BEFORE WE DESTROYED IT, THE PRINTER FED
PAPER BY RUNNING THE FEED IN REVERSE UNTIL PAPER WAS PULLED FROM THE
TRAY. THEN IT SWITCHED BACK TO NORMAL ROTATION TO PULL IT THE REST
OF THE WAY. THIS SWITCH OVERRIDES THE DIRECTION OF TRAVEL TO KEEP
THE PRINTER MOVING IN THE RIGHT DIRECTION.
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12.
LASTLY, ATTACH SOME DEVICE TO THE UNDERSIDE OF THE PRINTER, AHEAD OF THE
PHOTOINTERRUPTER THAT WILL TURN THE BASIN SCREW WHEN THE PRINTER MOVES
BACKWARDS (ONLY). i USED SOME POSTER BOARD AND A BIT OF
RUBBER. THIS SHOULD BE AS LATERALLY RIGID AS POSSIBLE, WHICH STILL
FLEXING UPWARDS EASILY.
ALSO, ATTACH THE SWITCH WITH THE RED
WIRES IN ANYWAY SUCH THAT IT TRIGGERS WHEN THE PRINT HEAD IS 1" PAST
THE BASIN.
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THIS LOWERS THE BASIN AFTER EACH LAYER.
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VOILA, YOU'RE DONE.
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