* '''DO NOT DRILL THROUGH MOTOR OR IDLER END GUIDE ROD POCKETS''' The 8mm holes the steel guide rods are pressed into is NOT a through hole! Mark the drill bit to help keep from drilling through the ends.
* '''DO NOT DRILL THROUGH MOTOR OR IDLER END GUIDE ROD POCKETS''' The 8mm holes the steel guide rods are pressed into is NOT a through hole! Mark the drill bit to help keep from drilling through the ends.
* The belt terminators (assembly steps detailed below) have a narrow passage that the belt passes through twice - that passage needs to be cleaned with the precision knife. (During printing of the terminators, small protrusions form, making it very difficult to slide the belt through the passage.) Additional insurance against loss of belt tension is afforded by the small wire ties on the belt tails.
* The belt terminators (assembly steps detailed below) have a narrow passage that the belt passes through twice - that passage needs to be cleaned with the precision knife. (During printing of the terminators, small protrusions form, making it very difficult to slide the belt through the passage.) Additional insurance against loss of belt tension is afforded by the small wire ties on the belt tails.
=Procedure=
== Procedure ==
# Remove sharp edges and strings from the printed parts with the precision knife.
# Wipe down the guide rods with a clean, dry cloth or paper towel to remove any abrasive dust that may damage bearings.
# Wipe down the guide rods with a clean, dry cloth or paper towel to remove any abrasive dust that may damage bearings.
# [[File:Athena_motor_end.JPG|thumb|right|Motor end on floor.]]Place the motor end assembly on the floor with the plywood base facing upwards.{{clear}}
# [[File:AthenaII mark drill.JPG|thumb|Mark depth to ream guide rod pockets on 8mm drill bit.]] The idler end placement jig has a small indentation across it for marking the proper depth to drill the motor and idler ends. Use the jig to mark the drill bit with a felt pen.{{Clear}}
# [[File:Athena_motor_measure_guide_pockets0.JPG|thumb|right|Measure the depth of the guide rod pockets with a suitable tool.]][[File:Athena_motor_measure_guide_pockets1.JPG|thumb|right|Transfer measurement to both ends of the guide rods.]] Drop a tool into one of the guide rod pockets and pinch between forefinger and thumb where the tool intersects the top of the pocket. Transfer the measurement to the ends of all guide rods, marking the approximate depth the rods should extend into the pockets.
# [[File:AthenaII mark guide rods.JPG|thumb|Mark ends of guide rod.]] [[File:AthenaII_mark_guide_rods2.JPG|thumb|right|Transfer to all guide rods.]] Use the idler end placement jig to similarly mark both ends of a guide rod. Transfer the markings from that guide rod to all other guide rods.{{Clear}}
# [[File:Athena_motor_end_guides.JPG|thumb|right|Motor end on floor.]]Start the 8mm guide rods into the motor end clamps, rotate while pushing into the clamp. The rods should fit tightly in the clamps but not so tightly that beating on them is required to seat them; ream the 8mm guide rod holes in each motor end with an 8mm drill bit if necessary.
# [[File:AthenaII ream ends.JPG|thumb|Ream motor and idler ends to mark on the 8mm drill.]] Ream the guide rod pockets in all idler and motor ends with the marked drill '''DO NOT DRILL ALL THE WAY THROUGH THE ENDS!''' If the ends are drilled through, they must be replaced.{{Clear}}
#* '''If considerable force is required to seat the guide rods:'''
# [[File:AthenaII guiderods idler.JPG|thumb|Press guide rods into idler end pockets.]] Press the guide rods into their pockets in the idler ends. The rods should be snug, but not require pounding to insert. If you feel too much force is required, pull out the rod and ream the pocket again.{{Clear}}
#** '''DO NOT pound the rods into the pockets!'''
# [[File:AthenaII lm8uu.JPG|thumb|Slide LM8UU bearings onto guide rods.]] Slide a LM8UU linear bearing onto each of the guide rods.{{Clear}}
#** Ream the guide rod pockets with an 8mm drill bit taking care to not drill through the bottom of the pocket.
# [[File:AthenaII idlers laying.JPG|thumb|Lay idlers and guide rods down such that the three slots in the idler are on top.]] Lay the assemblies down such that the three slots in the idler end are on top.{{Clear}}
#** Try again seating the guide rods in their pockets.{{clear}}
# [[File:AthenaII guiderods motor.JPG|thumb|Press guide rods into motor end pockets.]] The motor ends have two slots on the side where the guide rod pockets are. When inserting the guide rods into the motor ends, these slots should be on the opposite side of the three slots in the idler end. If the previous step was followed, the two slots in the motor ends will be on the bottom as you insert the guide rods.{{Clear}}
# [[File:Athena_grease_lm8uu.JPG|thumb|right|Apply grease to interior of LM8UU bearings.]]Dip the back of the handle of the precision knife in grease and work the grease into the LM8UU bearings. This is an essential step - failure to adequately lubricate the bearings will cause premature failure of bearings and grooving of guide rods.{{clear}}
# [[File:AthenaII guiderods idler.JPG|thumb|Check that rods are fully inserted.]] With both ends on the rods ''and in the correct orientation'' (slots on opposite sides of guide rods), fully insert the guide rods by pushing the assmebly down on the floor. Check the depth of the guide rods against the marks on the rods; the marks should be just above the pocket (see picture).{{Clear}}
# [[File:Athena_lm8uu_installed.JPG|thumb|right|LM8UU bearings on guide rods.]]Slide lubricated LM8UU bearings onto the rods – one per rod. Repeatedly slide the bearings up and down the guide rod. The force required to move the bearing will decrease with continued movement.{{clear}}
# [[File:AthenaII idler jig.JPG|thumb|Insert idler placement jig with wide side facing slots.]] Press the idler placement jig into the end of the idler end with the wide side of the jig facing the three slots.{{Clear}}
# [[File:Athena_idler_end_insert.JPG|thumb|right|Push on the idler end.]]Align the guide rods with their clamps in the idler end lining up the limit switch wire exit with one of the vertexes having the slotted motor-side linking board between them. Carefully push the idler end assembly onto the guide rods until all are just started into their clamps.{{clear}}
# [[File:AthenaII attach idler.JPG|thumb|Align jig with donut and attach with #6 x 3/4" sheet metal screws.]] A friend is useful for this step and it is important that the jig is properly placed as this sets printer geometry, ensuring print quality. Lay the plywood donut on the table, ugly side up. Place the wide side of the idler placement jig against a short inside leg of the hexagon, making sure the jig is fully flush against the leg. Start one #6 x 3/4" sheet metal screw into the donut, but don't tighten until you have the jig properly placed. Tighten the screw, check the jig position and run the remaining screws into the donut. Repeat this step with the remaining two idler/guide/motor assemblies.{{Clear}}
# [[File:Athena_rap_idler_end.JPG|thumb|right|Push the idler end onto the guide rods.]]'''Avoid fully seating just one set of rods in a single clamp - they may bind and it can be difficult to correct.''' Working in a circle around the idler end assembly, gently push on an idler end seating the entire idler end assembly on the guide rods little by little.
# [[File:AthenaII attach base.JPG|thumb|Attach the hexagonal base.]] A friend is useful for this step as well (and generally are in other areas in life). Carefully lay the assembly on its side and position the hexagonal base such that the guide rods rest in their reliefs cut in the base (see picture). Firmly push the guide rods into their reliefs and attach the base with a pair of #6 x 3/4" sheet metal screws. Rotate the assembly and repeat with remaining sides.{{Clear}}
#* '''If significant force is required to seat the guide rods:'''
# [[File:Athena motor pulley.JPG|thumb|Attch pulleys.]] Place pulleys on the motor shafts so that approximately 5mm of shaft extends beyond end of pulley (see picture). Rotate pulley so that one set screw will engage with the flat portion of the shaft and tighten that set screw. Tighten the second set screw. Repeat with remaining pulleys and motors.{{Clear}}
#** '''DO NOT pound the idler end onto the rods!'''
# [[File:AthenaII secure motors.JPG|thumb|Secure motors to the motor ends.]] Stand the assembly up such that the motor end is on top. Slide a motor onto the motor end positioned such that the wires exit right or left, not up or down. Start a M3 x 12 mm socket head cap screw with washer through the interior hole in the motor end; do not tighten the screw (needlenose pliers or tweezers is helpful). Similarly start the other three screws and tighten them all after the last one was started. Repeat with the other two motor ends. Flip the assembly over so the idlers are on top.{{Clear}}
#** Working around the idler end, pull up on it while holding the motor end down with your feet; DO NOT pull just one of the idler ends off as other rods will become jammed, causing breakage.
# [[File:AthenaII idler bearings.JPG|thumb|Assemble idler bearings.]] Create a cartridge of idler bearings and M8 washers in the following sequence: M8 washer - 608zz bearing - 608zz bearing - M8 washer. Insert the cartridge into the interior of an idler end and align as best you can with the 8mm hole.{{Clear}}
#** Once the idler end is off, ream the guide rod pockets with an 8mm drill bit taking care to not drill through the bottom of the pocket.
# [[File:AthenaII align idlers.JPG|thumb|Align idlers and secure in place with M8 x 40mm bolt.]] Use a thin tool (2.5mm allen wrench or small screwdriver) to better align the washer/bearing cartridge. When they are reasonably well aligned, carefully insert the 8mm drill bit to finalize alignment. Push a M8 x 40mm bolt through the assembly from the exterior side of the idler end. Secure in place with a M8 flat washer and M8 nut. Repeat with remaining two idler ends.{{Clear}}
#** Try again seating the idler end on the guide rods.{{clear}}
# [[File:AthenaII belts.JPG|thumb|String belts over pulleys and idler bearings.]] Make a loop in the belt and insert through the top of the motor end on one side of the motor. Rotate and move the loop such that it engages the pulley. With the guide rods nearest you (such that other two sets are farther away) pass the belt over the idler bearing starting from your left side (the side of the idler end nearest the bearings). The two ends of the belt should meet on the left side. See picture in next step.{{Clear}}
# [[File:Athena_check_depth_of_rods.JPG|thumb|right|Check that the rods are fully seated in their pockets by noting position of the lines on the guide rods marking depth of pocket.]]Check the marks on the ends of the guide rods to insure that the guide rods are completely seated in their pockets. Take corrective action if they are not.{{clear}}
# [[File:AthenaII fixed belt terminator.JPG|thumb|Attach fixed belt terminator.]] The fixed belt terminator (longer of the terminators) has a pocket for the head of an M3 screw. That pocket must face the exterior of the printer. With the fixed belt terminator properly oriented, slide the end of the belt coming from the idler bearing through the terminator, around its end and then insert the end of the belt back into the terminator. Pull the terminator all the way to the end of the loop. When properly attached, a short tail of belt should extend from the end of the terminator (see picture).
# [[File:Athena_check_printer_height.JPG|thumb|right|Use a vertical board to check printer height by noting gap between top donut and vertical board with the bottom of the vertical board flat against work surface.]]Check the printer height by standing a vertical board against each of the apexes noting that there should be about a 1mm-2mm gap between the plywood donut and the top of the vertical board:
# The free belt terminator (shorter) has no special orientation. Slip the opposite end of the belt through the free terminator and make a loop around its end. Pulling the fixed terminator and free terminator towards each other so the belt is in tension, position the belt loop such that it is 25 mm to 35 mm below the fixed terminator. Slide the free terminator towards the loose tail of the loop and hold it in place at the end of the tail. Slide the tail into the terminator and pull the terminator to the end of the loop.{{Clear}}
#* If the gap is larger than about 2mm, the rods are not fully seated:
# [[File:AthenaII belt tails.JPG|thumb|Secure belt tails with a pair of small wire ties on each end of the belt; clip belt if longer than 35 mm.]] Secure the belt tails immediately above and below the fixed and free belt terminators, respectively. Belt tails should be 25 mm to 35 mm long; excess should be trimmed off.{{Clear}}
#** Carefully remove the idler end assembly by carefully pulling up on it while holding the motor end on the floor with your feet. Work around the idler end assembly pulling each idler end little by little.
# [[File:AthenaII tighten belts.JPG|thumb|Tighten belts.]] Rotate the frame such that you're looking at one of the apexes across the interior of the frame. Start a large wire tie through the fixed belt terminator and then back into the interior of the frame through the free belt terminator. Secure the wire tie and use a needlenose pliers or lineman's pliers to pull the wire tie until the belt twangs when plucked (regular pliers tend to cut through the wire tie with potentially catastrophic consequence).{{Clear}}
#** Remove all the guide rods from their pockets.
# Repeat the previous five steps with the two remaining apexes.
#** Ream the guide rod pockets with an 8mm drill bit.
# [[File:AthenaII limit switches.JPG|thumb|Attach limit switches.]] With the tip of the precision knife, ream the small holes in the idler ends where the screws secure the limit switches. This makes starting the screws much easier, but don't get carried away. Prepare six M2 x 12 mm socket head cap screws with M2 flat washers on them. The limit switches are both screwed and epoxied to the idler ends, so having the screws ready to go helps since celerity is required to get the switches in place before the epoxy cures. Note that the switches are positioned such that the tab is facing the nearest guide rod (see picture). Mix a small amount of plastic epoxy and smear a ''thin'' layer on the side of the switch mating with the idler end. Secure the epoxied switch in place with a pair of M2 screws.
#** Clean out the pockets by turning the motor and idler end over and rapping on the back.
# [[File:AthenaII limit switch wires.JPG|thumb|Route the limit switch wires.]] All of the limit switch wires will run down one of the apexes. There are small holes in the tops of the idler ends through which the limit switch wires are run. Route the wires from two of the apexes to the third such that they neatly meet at the hole exiting the top, right of the third idler end (see picture). The holes are small; when running all three through the last one, pull one pair at a time and with the last wire, pull the previous two towards the interior and then use them to help the third pair through.{{Clear}}
#* If there is no gap or the motor end sits off the floor with the vertical board in place:
# [[File:AthenaII grease rods.JPG|thumb|Note thin coating of grease on the guide rods.]] With a paper towel, smear a thin layer of white lithium grease on the guide rods. This is an essential step - failure to adequately lubricate the bearings will cause premature failure of bearings and grooving of guide rods.{{Clear}}
#** Check the length of the vertical boards, they should be 605mm +/- 2mm. If boards are the correct length, continue, below:
#** Disassemble the printer per instructions, above. Remove all of the guide rods from their pockets.
#** With a flashlight, insure that the bottoms of the guide rod pockets were not drilled through. If they were, replace the damaged motor or idler end(s).
#** Check the length of the guide rods, they should be 590mm +/- 2mm.
== Navigation ==
# Return the printer to the work surface with the idler end down.
# [[File:Athena_belt_over_idler.JPG|thumb|right|Thread timing belt so ends are on the left side.]]Thread the belt through the right side of the idler box (side with the narrower gap between idler pulley and idler box) with the cogged side riding on the idler bearing. A flat screwdriver blade inserted at an angle into the box facilitates threading.{{clear}}
# [[File:Athena_belt_over_pulley.JPG|thumb|right|Loop belt and slide over pulley.]]Make a loop with the opposite end of the belt and slide it over the pulley on the motor taking care to not twist the belt. The ends of the belt should meet on your left side. {{clear}}
# [[File:Athena_fixed_belt_terminator0.JPG|thumb|right|Make sure there's enough belt to pass through the terminator '''large screw hole facing out'''.]]Hold the fixed (longer) belt terminator so that the larger screw hole faces you and the entry slot is facing down. Push the end of the belt passing over the idler through the slot in the belt terminator, wrap the belt around the rounded portion and then back into the slot. Push the belt into the slot such that it assumes the bend required to go back through the slot and pull the belt terminator tight.{{clear}}
# Repeat the process with the free (short) belt terminator on the opposite end of the belt. Note that there is no special orientation required for the free belt terminator.
# [[File:Athena_check_gap_between_terminators.JPG|thumb|right|Adjust terminator positions until gap is about 25mm (1").]]Check the length of the gap between the two belt terminators. The gap should be about 25 mm (1") long. Adjust the position of one of the terminators (choose the terminator that was easiest to install) to set the gap correctly.
# [[File:Athena_fix_belt_tails.JPG|thumb|right|Secure belt tails with small wire ties.]]Secure belt tails to the belt with small wire ties. This ensures that the belt doesn't slip when applying tension. Snip off the ends of the wire ties. Snip off the loose tails of the belt leaving about 2cm (1") above the wire tie.{{clear}}
# Install belts and terminators on the remaining two apexes.
# Rotate the frame so that the motor end is on the work surface.
# [[File:Athena_belt_tensioner.JPG|thumb|right|Large wire tie belt tensioner. ]]Start a large wire tie through the fixed (long) belt terminator '''starting from the interior of the printer'''. Ensuring that the belt is not twisted, thread the end of the wire tie through the free (short) belt terminator's larger hole and secure the wire tie. Do not pull the wire tie tightly yet.{{clear}}
# [[File:Athena_tensioning_belt.JPG|thumb|right|Pull the large wire tie tight to tension the belt.]]Rotate the printer so that the end of the wire tie is pointing towards you. Grip the wire tie clamp with your non-dominant hand and the end of the wire tie with a pair of pliers in your dominant hand. Pull firmly on the end of the wire tie, building tension in the timing belt. Pull reasonably hard but not so hard as to break the wire tie. Readjust the belt terminators and repeat. The belt should be tensioned such that it can be plucked like a guitar string and produce a deep bass tone.{{clear}}
# [[File:Athena_finished_tensioning.JPG|thumb|right|Tensioned belt.]]'''Leave about 25mm (1") of the large wire tie.''' Snip off the end of the wore tie, leaving about 25mm (1") to grip if the belt requires future tensioning.{{clear}}
# Repeat belt tensioning with remaining two apexes.
# [[File:Athena_ream_carriages.JPG|thumb|right|Ream limit switch screw holes in carriages.]][[File:Athena_screws_in_carriages.JPG|thumb|right|Plastiform threads in carriage limit switch screw pockets.]]Carefully ream the holes for the limit switch engagement screws in the carriages with the tip of the precision knife. Plastiform M3 x 12mm screws into the holes leaving the heads of the screws sitting proud of the top of the carriages.{{clear}}
# [[File:Athena_test_carriage.JPG|thumb|right|Check that carriages don't drag on guide rods.]]Fit a carriage over a pair of guide rods, but not over the LM8UU bearings. Slide the carriage up and down the rods checking for clearance. If the carriage drags on the rods, open the guide rod passages with the precision knife. Repeat until the carriages ride on the guide rods with little force.{{clear}}
# [[File:Athena_ream_carriage.JPG|thumb|right|Reaming carriage belt mount hole in web.]]Orient a carriage over a pair of LM8UU bearings with the '''magnets facing the interior and angled towards the motor end'''. Snap the carriage on the LM8UU bearings with the '''magnets facing the interior and angled towards the motor end'''. Position the carriage and fixed belt terminator so that the holes in each align. Ream the hole with a 3mm drill bit.
# [[File:Athena_fix_terminator_to_carriage.JPG|thumb|right|Fix carriage to terminator with M3 x 16mm screw.]]Secure the fixed terminator to the carriage with an M3 x 16mm screw and nut with a washer on the nut side only. The head of the screw should be fully seated in the recess in the belt terminator.{{clear}}
# Fix the belt terminators on the remaining two apexes.
# Prepare 12 M3 x 50mm screws with washers.
# Be selective about which faces of the vertical boards are exposed (facing outward) and place M3 x 50mm screws in each of the four holes so that the screw heads or on the side you wish to have facing out.
# [[File:Athena_vertical_to_idler0.JPG|thumb|right|Insert M3 x 50mm screws into idler end.]][[File:Athena_vertical_to_idler1.JPG|thumb|right|Secure with nut and washer.]]Starting at the idler end, insert the M3 x 50 screws through their matching holes in the idler and motor ends. Secure the screws to the idler end with a washer and nut, but do not tighten them. Repeat with remaining two apexes and vertical boards.{{clear}}
# [[File:Athena_vertical_to_motor.JPG|thumb|right|Tighten M3 x 50mm screws with nut only on motor ends.]]Invert the frame so that the motor end is facing up. Secure the M3 x 50mm screws with a nut only - there is not enough room for a washer. Tighten the screws on both the motor and idler ends. Repeat with remaining two apexes and vertical boards.{{clear}}
# [[File:Athena_tighten_rod_clamps.JPG|thumb|right|Tighten guide rod clamps on motor and idler ends.]]Tighten the M3 x 16mm screws securing the guide rods to the motor and idler ends.{{clear}}
# [[File:Athena_mount_extruder_drive.JPG|thumb|right|Attach the extruder drive to the vertical board that the limit switch wires run down.]]Return the printer to its upright position with motors down. Rotate the printer so that the vertical board with the limit switch wires is facing you. Mount the extruder drive with the larger exit hole angled upwards to the right (see photo) with two #6 x 1/2" sheet metal screws and positioned just above the mid point of the vertical board. The drive should be angled with the motor down to the right as shown in the photo. [[MOST_RepRap_braiding|Braid]] the extruder drive motor wires as far as the motor end only.{{clear}}
# [[File:Athena_quick_connect_extruder_drive.JPG|thumb|right|Thread the quick connect on the extruder drive outlet.]]Locate the printed quick connect thumb screw and remaining quick connect fitting and fit the thumbscrew onto the quick connect fitting. Taking care to insure that the quick connect threads are aligned with the extruder drive outlet, thread the quick connect onto the extruder drive.{{clear}}
# [[File:Athena_extrur_drive_inlet.JPG|thumb|right|Push the PTFE inlet tube into the extruder drive inlet port.]]Push the short piece of PTFE tubing into the hole in the inlet port of the extruder drive. (This inlet tube facilitates insertion of filament while printing.){{clear}}
# [[File:Athena_grease_ball_bearings.JPG|thumb|right|Apply a small amount of grease to the ball bearings on the ends of the connecting rods.]][[File:Athena_bearings_in_magnets.JPG|thumb|right|Engage ball bearings in carriage magnets.]]Push all of the carriages towards the top of the printer. Apply a small amount of grease to the ball bearings on the ends of the connecting rods and engage one rod with each of the magnets in the carriages.{{clear}}
# [[File:Athena_attach_end_effector.JPG|thumb|right|Attach the end effector.]]Attach the end effector to the opposite ends of the connecting rods insuring that the tie rods are parallel.{{clear}}
# [[File:Athena_insert_bowden_sheath_drive.JPG|thumb|right|Insert the Bowden sheath.]]Insert the loose end of the Bowden sheath (PTFE tubing attached to end effector) into the quick connect on the extruder drive.{{clear}}
# [[File:Athena_fix_effector_wires.JPG|thumb|right|Braid and secure wires to Bowden sheath.]]Braid the three sets of wires exiting the end effector (wrap the two smaller wires in opposing directions around the larger wires) and fix to the Bowden sheath with small wire ties. '''Do not braid the wires the entire length - leave the last 20cm (~8") unbraided to facilitate inserting the wires through the motor end wire passage in a later step.''' Do not over tighten the wire ties to avoid constricting filament inside the sheath. Snip off the tails from the wire ties.{{clear}}
# [[File:Athena_frame_external_wires.JPG|thumb|right|Bring wires together at base of extruder drive motor.]][[File:Athena_frame_wire_motor_end.JPG|thumb|right|Carefully feed wires through the guide and hole in motor end.]]Wires from the limit switches, extruder drive motor and end effector should all meet at the bottom of the extruder drive motor. Gather them neatly together and then carefully feed them through the wire guide and hole in the motor end directly below the extruder drive motor. Start the smaller wires through the motor end first, then the larger. Braids are more difficult to feed through the hole - remove braid up to the hole if necessary. Carefully pull the wires taught along the edge of the vertical board. Inverting the printer so the motor end is up makes the process much easier.{{clear}}
# [[File:Athena_mount_spool_holder.JPG|thumb|right|Mount the spool holder midway between the extruder drive and bottom of the vertical board.]] The spool holder doubles as a wire management device. Press it onto the vertical board with all of the wires between it and the edge of the vertical board. Mount the spool holder pivot to the vertical board midway between the extruder drive and bottom of the printer with two #6 x 1/2" sheet metal screws.{{clear}}
# [[File:Athena_mount_spool_arm.JPG|thumb|right|Mount the spool arm to the pivot.]]Locate the conical spool arm retainer and pass an M3 x 12mm socket head cap screw through it. Place the spool arm on the pivot with the arm pointing outward and tighten the screw and retainer to the pivot.{{clear}}
DO NOT DRILL THROUGH MOTOR OR IDLER END GUIDE ROD POCKETS The 8mm holes the steel guide rods are pressed into is NOT a through hole! Mark the drill bit to help keep from drilling through the ends.
The belt terminators (assembly steps detailed below) have a narrow passage that the belt passes through twice - that passage needs to be cleaned with the precision knife. (During printing of the terminators, small protrusions form, making it very difficult to slide the belt through the passage.) Additional insurance against loss of belt tension is afforded by the small wire ties on the belt tails.
Remove sharp edges and strings from the printed parts with the precision knife.
Wipe down the guide rods with a clean, dry cloth or paper towel to remove any abrasive dust that may damage bearings.
Mark depth to ream guide rod pockets on 8mm drill bit. The idler end placement jig has a small indentation across it for marking the proper depth to drill the motor and idler ends. Use the jig to mark the drill bit with a felt pen.
Mark ends of guide rod.Transfer to all guide rods. Use the idler end placement jig to similarly mark both ends of a guide rod. Transfer the markings from that guide rod to all other guide rods.
Ream motor and idler ends to mark on the 8mm drill. Ream the guide rod pockets in all idler and motor ends with the marked drill DO NOT DRILL ALL THE WAY THROUGH THE ENDS! If the ends are drilled through, they must be replaced.
Press guide rods into idler end pockets. Press the guide rods into their pockets in the idler ends. The rods should be snug, but not require pounding to insert. If you feel too much force is required, pull out the rod and ream the pocket again.
Slide LM8UU bearings onto guide rods. Slide a LM8UU linear bearing onto each of the guide rods.
Lay idlers and guide rods down such that the three slots in the idler are on top. Lay the assemblies down such that the three slots in the idler end are on top.
Press guide rods into motor end pockets. The motor ends have two slots on the side where the guide rod pockets are. When inserting the guide rods into the motor ends, these slots should be on the opposite side of the three slots in the idler end. If the previous step was followed, the two slots in the motor ends will be on the bottom as you insert the guide rods.
Check that rods are fully inserted. With both ends on the rods and in the correct orientation (slots on opposite sides of guide rods), fully insert the guide rods by pushing the assmebly down on the floor. Check the depth of the guide rods against the marks on the rods; the marks should be just above the pocket (see picture).
Insert idler placement jig with wide side facing slots. Press the idler placement jig into the end of the idler end with the wide side of the jig facing the three slots.
Align jig with donut and attach with #6 x 3/4" sheet metal screws. A friend is useful for this step and it is important that the jig is properly placed as this sets printer geometry, ensuring print quality. Lay the plywood donut on the table, ugly side up. Place the wide side of the idler placement jig against a short inside leg of the hexagon, making sure the jig is fully flush against the leg. Start one #6 x 3/4" sheet metal screw into the donut, but don't tighten until you have the jig properly placed. Tighten the screw, check the jig position and run the remaining screws into the donut. Repeat this step with the remaining two idler/guide/motor assemblies.
Attach the hexagonal base. A friend is useful for this step as well (and generally are in other areas in life). Carefully lay the assembly on its side and position the hexagonal base such that the guide rods rest in their reliefs cut in the base (see picture). Firmly push the guide rods into their reliefs and attach the base with a pair of #6 x 3/4" sheet metal screws. Rotate the assembly and repeat with remaining sides.
Attch pulleys. Place pulleys on the motor shafts so that approximately 5mm of shaft extends beyond end of pulley (see picture). Rotate pulley so that one set screw will engage with the flat portion of the shaft and tighten that set screw. Tighten the second set screw. Repeat with remaining pulleys and motors.
Secure motors to the motor ends. Stand the assembly up such that the motor end is on top. Slide a motor onto the motor end positioned such that the wires exit right or left, not up or down. Start a M3 x 12 mm socket head cap screw with washer through the interior hole in the motor end; do not tighten the screw (needlenose pliers or tweezers is helpful). Similarly start the other three screws and tighten them all after the last one was started. Repeat with the other two motor ends. Flip the assembly over so the idlers are on top.
Assemble idler bearings. Create a cartridge of idler bearings and M8 washers in the following sequence: M8 washer - 608zz bearing - 608zz bearing - M8 washer. Insert the cartridge into the interior of an idler end and align as best you can with the 8mm hole.
Align idlers and secure in place with M8 x 40mm bolt. Use a thin tool (2.5mm allen wrench or small screwdriver) to better align the washer/bearing cartridge. When they are reasonably well aligned, carefully insert the 8mm drill bit to finalize alignment. Push a M8 x 40mm bolt through the assembly from the exterior side of the idler end. Secure in place with a M8 flat washer and M8 nut. Repeat with remaining two idler ends.
String belts over pulleys and idler bearings. Make a loop in the belt and insert through the top of the motor end on one side of the motor. Rotate and move the loop such that it engages the pulley. With the guide rods nearest you (such that other two sets are farther away) pass the belt over the idler bearing starting from your left side (the side of the idler end nearest the bearings). The two ends of the belt should meet on the left side. See picture in next step.
Attach fixed belt terminator. The fixed belt terminator (longer of the terminators) has a pocket for the head of an M3 screw. That pocket must face the exterior of the printer. With the fixed belt terminator properly oriented, slide the end of the belt coming from the idler bearing through the terminator, around its end and then insert the end of the belt back into the terminator. Pull the terminator all the way to the end of the loop. When properly attached, a short tail of belt should extend from the end of the terminator (see picture).
The free belt terminator (shorter) has no special orientation. Slip the opposite end of the belt through the free terminator and make a loop around its end. Pulling the fixed terminator and free terminator towards each other so the belt is in tension, position the belt loop such that it is 25 mm to 35 mm below the fixed terminator. Slide the free terminator towards the loose tail of the loop and hold it in place at the end of the tail. Slide the tail into the terminator and pull the terminator to the end of the loop.
Secure belt tails with a pair of small wire ties on each end of the belt; clip belt if longer than 35 mm. Secure the belt tails immediately above and below the fixed and free belt terminators, respectively. Belt tails should be 25 mm to 35 mm long; excess should be trimmed off.
Tighten belts. Rotate the frame such that you're looking at one of the apexes across the interior of the frame. Start a large wire tie through the fixed belt terminator and then back into the interior of the frame through the free belt terminator. Secure the wire tie and use a needlenose pliers or lineman's pliers to pull the wire tie until the belt twangs when plucked (regular pliers tend to cut through the wire tie with potentially catastrophic consequence).
Repeat the previous five steps with the two remaining apexes.
Attach limit switches. With the tip of the precision knife, ream the small holes in the idler ends where the screws secure the limit switches. This makes starting the screws much easier, but don't get carried away. Prepare six M2 x 12 mm socket head cap screws with M2 flat washers on them. The limit switches are both screwed and epoxied to the idler ends, so having the screws ready to go helps since celerity is required to get the switches in place before the epoxy cures. Note that the switches are positioned such that the tab is facing the nearest guide rod (see picture). Mix a small amount of plastic epoxy and smear a thin layer on the side of the switch mating with the idler end. Secure the epoxied switch in place with a pair of M2 screws.
Route the limit switch wires. All of the limit switch wires will run down one of the apexes. There are small holes in the tops of the idler ends through which the limit switch wires are run. Route the wires from two of the apexes to the third such that they neatly meet at the hole exiting the top, right of the third idler end (see picture). The holes are small; when running all three through the last one, pull one pair at a time and with the last wire, pull the previous two towards the interior and then use them to help the third pair through.
Note thin coating of grease on the guide rods. With a paper towel, smear a thin layer of white lithium grease on the guide rods. This is an essential step - failure to adequately lubricate the bearings will cause premature failure of bearings and grooving of guide rods.
