Pen Plotter

• Fit tests: rail, slider, and wheel strip
• Y carriage, left
• Y carriage, right
• X plate
• Pen carriage
• Pen slider
• Y motor bracket, left
• Y front base, left
• Y idler fork
• X idler fork
• Y chain anchor

1. Print the three fit tests first.
2. Slide the fit slider onto the fit rail. It must slide by its weight, with no side play.
3. Put a V-wheel in each hole of the fit wheel strip. Lay the strip across the end of a frame rail.
4. Turn the eccentric spacer. Both wheels must grip the slots before the eccentric reaches its end.
5. Print the other parts in the orientation of each STL, with supports off.

Tip If a fit test is tight or loose, change the clearance in hardware/shape.py and print it again. The build guide PDF gives the values.

• M5 heat-set inserts, long, 9.5 mm
• M3 heat-set inserts, 5.7 mm

1. Set the iron to 220 °C.
2. Put a long M5 insert in the front outer wheel boss of each Y carriage. Push it straight down until its top is flush.
3. Put a long M5 insert in the bottom wheel boss of the X plate.
4. Put an M3 insert in each standoff of the two front bases.
5. Put an M3 insert in each standoff of the X endstop wall on the left Y carriage.

Tip Let each part cool for one minute. Then turn a screw in and out once.

• Y carriage, left
• Y carriage, right
• Creality CR-10 V3, dismantled
• M5 socket head screw kit, with nuts
• M5 nyloc nuts and small M5 washers

1. Front outer wheel: put an M5 × 30 screw up through a wheel and a 6 mm spacer into the insert.
2. Back outer wheel: put an M5 × 35 screw up through a wheel and an eccentric spacer. Put a nyloc nut on top.
3. Put an M5 × 35 screw down through the inner boss.
4. Stand the frame on the table. Set each carriage on its rail from above, the outer wheels in the outer side slot.
5. Put a 6 mm spacer, the inner wheel, and a nyloc nut on the inner screw.
6. Turn each eccentric until the play is gone. The carriage must still roll freely over the full length.
7. Make the two diagonals of the frame equal. Then tighten the bar screws.

Caution Too much preload makes flat spots on the wheels. Stop when the play is gone.

• Y motor bracket, left
• Y motor bracket, right
• GT2 20T pulley, 5 mm bore
• M3 socket head screw kit, 6 to 30 mm, with nuts
• M5 socket head screw kit, with nuts
• M5 drop-in T-nuts for 2020

1. Hold a 42-40 motor on the outer face of each bracket, the shaft to the inside. Put in four M3 × 10 screws from the inside.
2. Put a GT2 pulley on each shaft. Line up its teeth with the inner top slot of the rail. Tighten the set screws on the flat.
3. Turn two M5 T-nuts into the back face slot of the back bar, near each end.
4. Screw each bracket to the back bar with two M5 × 12 screws.
5. Plug in each motor cable. It runs on the table behind the frame.

Tip Fit the motor screw that the bar hides before the bracket goes on the bar.

• Y front base, left
• Y front base, right
• Y idler bracket, left
• Y idler bracket, right
• Y idler fork
• GT2 20T toothed idler, 5 mm bore
• M3 heat-set inserts, 5.7 mm

1. Push an M3 nut into the slot of each Y idler fork.
2. Hold an idler between the cheeks, a small washer on each side. Put an M5 × 30 screw through and tighten the nyloc nut.
3. Screw a front base on each end of the front bar with two M5 × 12 screws in T-nuts.
4. Hold an idler bracket under the two lips. Put an M3 × 12 screw down through the inner lip.
5. Set each fork in its bracket. Put an M3 × 20 tension screw through the end wall. Turn it two turns only.
6. Screw a Y endstop board on each front base with two M3 × 8 screws, the switch to the back.

Tip Home is the front left corner. A fin on each carriage plate pushes the lever of its switch.

• Nylon M3 standoffs, 4 mm
• Cable ties, 2.5 mm

1. Hold the base board on the back face of the back bar, 71 mm from the left end.
2. Put a 4 mm nylon standoff under each of its two holes.
3. Put a cable tie through each hole and its standoff, round the bar. Pull the ties tight.
4. Plug in Y (left motor), Z1 (right motor), Y- (left endstop), and Z- (right endstop).
5. Push the big 2 × 8 plug into the header, pointing up.

Tip Lay the endstop wires in the bottom slots and press the slot cover strip over them.

• X plate
• Pen carriage
• M3 socket head screw kit, 6 to 30 mm, with nuts
• M5 socket head screw kit, with nuts
• M5 nyloc nuts and small M5 washers

1. Hold the pen carriage on the front of the X plate. The three wheel bosses go through its round holes.
2. Put four M3 × 12 screws from the back through the plate into the pen carriage. Do not overtighten them.
3. Top left wheel: an M5 × 30 button head through the wheel and a 6 mm spacer. Put a nyloc nut on the front.
4. Top right wheel: an M5 × 35 button head through the wheel and the eccentric spacer. Leave its nut loose.
5. Bottom wheel: an M5 × 25 button head through the wheel and a 6 mm spacer into the insert.

• M5 drop-in T-nuts for 2020
• M5 socket head screw kit, with nuts
• M3 socket head screw kit, 6 to 30 mm, with nuts

1. Slide the X plate onto the beam from one end. The top wheels go in the top slot, the bottom wheel in the bottom slot.
2. Turn the eccentric of the top right wheel until the plate has no play. Tighten its nut.
3. Turn an M5 T-nut into the back slot of the beam, 14 mm from each end.
4. Lay the beam on the two saddles, the pen carriage to the front.
5. Screw the beam to each carriage with one M5 × 12 screw through the back wall of the saddle.
6. Screw the X endstop board on the X endstop wall with two M3 × 8 screws.

Tip Keep the top and the bottom slots of the beam free. The X belt runs in them.

• X idler fork
• M3 socket head screw kit, 6 to 30 mm, with nuts
• M5 nyloc nuts and small M5 washers

1. Put a GT2 pulley on the shaft of the 42-34 motor. Do not tighten it yet.
2. Hold the motor behind the left beam end, the shaft to the front through the motor wall. Put in three M3 × 10 screws from the front.
3. Slide the pulley until its teeth are on the beam center line. Tighten the set screws.
4. Push an M3 nut into the slot of the X idler fork. Put the idler and two small washers in the fork on an M5 × 30 screw and a nyloc nut.
5. Set the fork in the seat past the right beam end. Put the M3 × 20 tension screw through the end wall. Turn it two turns only.

Tip The X motor rides on the gantry. The shorter 42-34 keeps the moving mass low.

• Nylon M3 standoffs, 4 mm
• Cable ties, 2.5 mm
• Servo extension, 70 cm, crimp kit, and 24 AWG wire

1. Hold the head board on the back face of the beam, 96 mm from the left side of the frame, the big header up.
2. Put a 4 mm nylon standoff under each hole. Put a cable tie through each hole and standoff, round the beam.
3. Plug in X (X motor), X- (X endstop), and the servo lead on BL_T.
4. Push the big 2 × 15 plug into the header from the top. Keep the cable straight for 35 mm.

Caution The two ties go round the beam. Push the X plate past them by hand before you power the motors.

• GT2 belt, 6 mm, glass fiber core, 5 m
• GT2 6 mm belt crimp clips, metal

1. Cut two Y belts about 1200 mm long and the X belt about 950 mm long.
2. Fold one end back 20 mm, teeth to teeth. Crimp a clip over the two layers, 1.5 mm from the fold.
3. Crimp the second clip 1135 mm from the first fold on each Y belt, and 898 mm on the X belt. Cut off the tail.
4. Turn each tension screw out to the end of its travel.
5. Y belts: lay each belt round its pulley and idler, teeth inside. Drop the clips into the clamp blocks of the carriage from the top.
6. X belt: feed it through the top slot of the beam, round the pulley, and back through the bottom slot. Push the clips into the X plate from the back.
7. Turn each tension screw in until its belt is tight.

Tip If a belt is too long, crimp a new clip closer to the other clip.

• CR-10 V3 control box and harness

1. Stand the control box on the table, left of the frame, the LCD to the front.
2. Tie the head cable to the back of the beam. Tie the base cable along the back bar.
3. Plug the two cables into the box. Check the mains voltage setting of the supply.
4. Connect the USB port of the box to the computer. Flash the plotter firmware.

Caution Keep the control box off until you complete the wiring checks in the full guide.

• Y chain anchor
• Drag chain, openable, 10 × 20 mm inside, R28
• Split wire loom, 1/2 inch
• Cable ties, 2.5 mm

1. Screw the chain anchor at the back left corner. One M5 × 12 screw goes up into a T-nut in the bottom outer slot of the rail.
2. Open the links of the drag chain. Lay in the head harness. Close the links.
3. Bolt the fixed end link to the anchor and the moving end link to the tab of the left carriage, with two M3 × 10 screws each.
4. Cut the split loom to 295 mm. Push the servo lead into it.
5. Tie the loom through the slot at the top left of the X plate.
6. Lead the loom over the beam. Tie its other end to the head harness, above the big plug.

Tip The loop of the loom hangs free behind the beam. It needs no printed holder.

• Small servo, 180°, SG90 type

1. Push the servo into its pocket, the shaft at the bottom. The wire goes out through the slot.
2. Put the two servo screws through the tabs. Plug the servo into the servo lead.
3. Send M5 (pen up), then M3 (pen down). Leave it at pen down.
4. Put the horn on the spline. The arm points at the tab of the slider, 10° below level.

Tip Tune the pen up and pen down angles with the knob menu.

• Pen slider
• M3 socket head screw kit, 6 to 30 mm, with nuts

1. Push an M3 nut into the slot in the top of the slider. Turn the M3 × 20 clamp screw in a few turns.
2. Slide the slider onto the dovetail rail of the pen carriage from the top.
3. Send M3 (pen down). Put the pen in the V bore until its tip touches the paper.
4. Tighten the clamp screw.

Tip Round pens of 8 to 15 mm fit the V bore. The weight of the slider and the pen is the pen force.

• Camera pole foot
• M6 × 16 socket head screw
• M3 socket head screw kit, 6 to 30 mm, with nuts
• M5 drop-in T-nuts for 2020

1. Turn two M5 T-nuts into the back face slot of the back bar, at the center.
2. Put the M3 nut and the M3 × 16 collar screw in the ears of the foot. Leave the screw loose.
3. Put the pole in the socket. Put the M6 × 16 screw up through the floor into the pole end.
4. Screw the foot to the back bar with two M5 × 12 screws. Tighten the collar screw.
5. Tie the USB cable of the webcam to the foot and to the pole.

1. Turn on the control box. Connect its USB port to the computer.
2. Send M119. Push each endstop by hand and check that it changes.
3. Send G28. Both Y sides go to the front switches. This squares the gantry.
4. Plot samples/square.gcode. Measure the square: it must be 40 × 40 mm.

Tip The full guide has the calibration and the first plots.