Cupcake X Stage Assembly

This page is part of the Cupcake CNC build sequence.


Building the X stage will take you about one and a half hours. You will need your previously assembled Y stage and 606 pulley. (See Cupcake Pulley Assembly.)

Parts List

  • Laser-cut stage parts
    • X stage
    • X left
    • X right
    • X front
    • X back
    • X rib
    • 2 X caps
    • 2 X clamps
  • NEMA 17 stepper motor
  • 17-tooth aluminum drive pulley
  • 1 M6 22mm bolt
  • 3 M6 nuts
  • 2 M3 washers
  • 4 flanged slide bearings
  • 25 M3 10mm bolts
  • 25 M3 nuts
  • 2 M8 supporting rods
  • 264 tooth continuous timing belt


Clamp the X belt to the X rib

  • Attach each X clamp to the front of the X rib through the top hole using an M3 bolt. Put a washer between the two pieces. Loosely thread a nut on to the bolt, but do not tighten. Rotate the two clamps so they do not cover the slots in the rib.
  • Place the belt against the front of the rib so that the teeth of the rib engage the slots in the rib. Lock down one of the clamps with another bolt.
  • The 264 tooth belts that come with the Cupcake kit are actually a little bigger than they should be, so you'll want to "kink" the belt a bit between the two clamps, as shown in the picture. If you find later that your belt is too loose, you can always go back and "kink" it a bit more. Likewise, if it's too tight, you can loosen it a couple of notches. Swing down the other clamp to hold the kink in place, and put a bolt in the lower hole of the clamp.
  • Tighten all nuts.

Install the flanged bearings

Please read the Cupcake Y Stage Assembly instructions for details on how to install the flanged bearings. Remember to exercise care and patience in installing the bearings; you don't want to break your stage sides! Yours will look a bit different because it will have hot glue on it and you'll have sanded the holes down a bit!

  • Carefully press the flanged press-fit bearings into the large holes in the X left and X right pieces. The flanges should end up on the sides of the pieces on which they are labeled.

Assemble the X stage

  • Place 3 M3 nuts on the lower three T-slots on the X right and X left pieces. (You can leave the two t-slots at the ends empty for now.)
  • Slot the X left and X right pieces into the X stage. The text on all three pieces should face outwards. Use six M3 bolts to tighten the sides to the stage.

Mount the stepper motor

  • Place the aluminum drive pulley on the stepper shaft, with the end with the set screws closer to the motor. Position it on the shaft so there is about one millimeter of shaft still visible between the motor and the pulley. You may need to shift the pulley higher later.
  • Using the small hex wrench, tighten both set screws on the pulley.
  • Place the motor inside the stage, with the wires facing inside (towards the front) of the stage.
  • Use the four 8mm (shorter) M3 screws to secure the motor to the X stage.

Mount the small pulley

  • Place the M6 bolt through the pulley. Use an M6 nut to fasten it to the bolt.
  • Adjust the distance from X the stage to the pulley by adding some additional washers and nuts (if you have printed pulleys, at least). Consider tightening the pulley later, because you'll probably want to adjust the distance again.
  • Place the bolt with the pulley on it into the slot on the X stage. Use an M6 nut to loosely attach it to the stage.

Place the Y stage on the X stage

  • Place the Y stage on the X stage. The side labelled "Y front" should face the front of the X stage (away from the motor).
  • Loop the Y stage belt around the motor pulley and the wooden pulley. It may take a bit of work to fit the belt around the flanges on the pulleys. Try rotating the pulley as you pull the belt over it.
  • NOTE: At least for my Batch 6 CupCake, I needed to tighten my tension pulley at this point as in the following steps I wound up covering it and couldn't hold the bolt as I tightened the nut - so tighten up here.
  • NOTE: As a guide, on my Batch 7 CupCake the inner bottom lip of the pulleys (and hence the drive belt) were around 6mm off the stage.

Mount the rod supports

  • Put M3 nuts into the slots at the ends of the X left and X right pieces.
  • Attach the X front piece to the X left and X right pieces with 10mm M3 bolts. Make sure that the label "X front" faces the front of the stage (away from the motor).
  • Attach the X back piece to the X left and X right pieces with 10mm M3 bolts. Make sure that the label "X back" faces the front of the stage.

Mount the M8 rods

  • Using an M3 bolt and nut, affix one of the X caps to the back of the X back piece.
  • Slide the M8 rods through the holes in the X front, the slide bearings in the Y stage, and into the holes in the X back.
  • If your rods are too long: It's okay (in fact, expected) that the rods will protrude slightly from the holes— you can clamp them down with the other X cap, and this will lock them in place without letting them slide around. If the rods are excessively long, though, we recommend filing them or grinding them down somewhat. Be careful not to shorten them too much, though!
  • Check if the aluminium drive pulley on the stepper motor and the wooden or printed pulley are about the same level as the belt on the Y stage. Adjust if needed.
  • Using an M3 bolt and nut, affix the other X cap to the front of the X front piece, locking the rods in place.
  • Slide the wooden pulley forward as far as you can to tighten the timing belt. When the belt is somewhat taut, tighten down the M6 nut on the bottom of the stage hard to keep the belt in place.

Install the rib and belt

  • Insert five M3 nuts into the slots in the X rib.
  • Insert the rib in the X stage so that the belt runs through the two narrow slots. Screw the rib into place with five 10mm M3 bolts.

That's it! With the exception of the endstops (which we'll get to later), your X-Y mechanism is complete!

Next step: Cupcake XY Stage Installation

Unless otherwise stated, the content of this page is licensed under GNU Free Documentation License.