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Preparing x-gantry

This set of work instructions is out of date!

What's shown here is for v3.0.5 of the LumenPnP. Instructions for the latest version of x-gantry still need to be written for LumenPnP v3.1.#.
Please note however, the QC Checklist is up to date.

Assemble the x-gantry-linear-axis

Prepare the x-motor-mount

  • Install 2x M5 Hex Nuts into x-motor-mount

  • Use an M5x16 bolt to align the hex nut with the hex pocket

  • Before continuing, add a small drop of Loctite to the side of the hex nut

  • You can then proceed to pull the hex nut fully into the hex pocket by tightening the bolt

  • Repeat this process for the second hex nut, when finished your x-motor-mount should match the images shown below:

Install NEMA 17 stepper motor onto x-motor-mount

  • Set timing-pulley height on NEMA 17 stepper motor shaft with jig

    • The 1st set screw tightened must contact the flat region of the NEMA 17 motor’s shaft
    • Tighten both set screws to 0.6 N/M

  • Bolt NEMA 17 motor onto motor mount with 4x M3x8 bolts

    • Tighten these bolts to 0.4 N/M
    • The motor connector should face towards the 2x pressed in M5 hex nuts when installed

Assemble x-axis tensioner and install onto x-idler mount

  • The pieces you will need are shown below

  • Press an M3 hex nut into the belt-tension-arm, followed by an M3x16 bolt

  • Thread the M3x16 bolt all the way through the belt-tension-arm, and then thread an M3 acorn nut onto the ends of the bolt.

    • Tighten the nut onto the bolt with pliers and an Allen wrench!

  • Install the idler-pulley with an M5x25 bolt and a nyloc M5 hex nut

    • Avoid over tightening the bolt, the idler-pulley should be able to spin freely without resistance.
  • Install belt-tension-arm onto x-idler-mount

    • Bolt the pieces together at the pivot point on x-idler-mount with an M5x40 bolt and a nyloc M5 hex nut.
    • Avoid over tightening the bolt, the belt-tensioner arm should be able to pivot smoothly without much resistance.
    • Ensure the belt-tensioner-arm is installed correctly on x-idler-mount (IE not backwards)
    • The acorn nut should be resting against the x-idler mount when installed correctly

Assemble x-motor-mount and x-idler mount onto alu-extrusion

needs work

Prepare the x-gantry’s toolhead-assembly

Top-camera-assembly preparation

  • Use the top-camera-focus-jig to pre-focus top-cameras

  • Connect top-camera-focus-jig to a laptop and open a native camera viewing application

  • Remove the top-camera lens cap

  • Loosen the set screw found on the side of the lens body that locks the focus

  • Install the top-camera fully into the top-camera-focus-jig, plugging the USB cable into the camera module afterwards

  • In Photobooth, change the selected camera to PnP Top to view the camera feed of the top-camera. The setup should now look like the following image


  • Rotate the camera lens until the live viewport shows the datum board as focused as possible

    Camera view before and after focusing shown above

  • Once the camera is focused, tighten the set screw to lock in the adjustments

  • Put a red dot on the camera PCB with a sharpie to denote that the camera has passed testing

  • Remove the top-camera from the top-camera-focus-jig and immediately replace the lens cap.

Assemble the top-camera-assembly

  • Installing top-ring-light into top-light-mount

    • Place the ring light facing downwards into the top-light-mount.
    • The LEDs will shine down, and the white plastic wire connector will face upwards.
  • Place top-camera-mount above top-light-mount, ensuring that the tab from the top-light-mount fits onto the side opposite the arms on the top-camera

    • These two prints will pinch the top ring light in place

  • Install top-camera into top-camera-mount.

    • Make sure the connector on the back side of the camera is between the two arms of the top-camera-mount.

  • Secure the whole stack in place with four M2.5x20mm screws in the outer four holes

    • Do not put the screws through the inner holes with metal circles around them
    • Tighten the screws enough so that all parts are tightly held together, however be cautious as these screws are threading directly into the plastic

X-gantry-back hex nut installation

  • Insert 2x hex nuts into x-gantry-back for later drag-chain-assembly attachment

  • Add a small amount of Loctite to the sides of the hex nuts to ensure they stay installed in transit to the customer

  • It is recommended to use a wide tool that can easily press down on the entire hex nut without allowing it to rock. This helps insert the hex nut into the print straight on.

  • However, be sure to switch to a narrow tool that can fully press hex nuts into the pockets

  • Insert 2x backside hex-nuts into x-gantry-back

  • Place the x-gantry-back-nut-plate jig onto the arbor press to hold x-gantry-back in a proper position during the following steps

  • Press the hex nuts into x-gantry-back until they are flush with the surface

  • The 2x adjustable sliding M5 hex nuts are not installed at this time because they can be loose and it would be inappropriate to fix them in place with Loctite

  • Insert all the remaining top-side hex nuts into x-gantry-back

  • Fully insert the 4x M5 hex nuts used for belt-clamp attachment

  • If the pockets for the 2x hex nuts used for attaching the top-camera assembly loosely fit the hardware, use Loctite to prevent to secure them

  • Insert the 2x hex nuts used for tension adjustment deep into the print, stopping once the threads are fully visible from the intersecting bolt hole

  • Install tensioner bar onto x-gantry back

X-gantry-front preparation

  • Install hex nuts into x-gantry-front, being sure to utilize the x-gantry-front-nut-plate fixture when installing hardware into the backside of the print.

  • Press an M5 nyloc hex nut into the backside of x-gantry-front

  • Install the 8x M3 hex nuts into the backside of the x-gantry-front, use a narrow tool to ensure that these pieces are fully inserted into the 3D print.

  • Insert the 2x hex nuts used for tension adjustment deep into the print, stopping once the threads are fully visible from the intersecting bolt hole

  • Install tensioner bar onto x-gantry-front

x-gantry-toolhead assembly

  • Install linear-rails by aligning them against the bumps on x-gantry-front

    • Uses 3x M3x14 bolts per rail
    • Tighten each bolt to 0.5 N/M

  • Install z-axis limit switch onto x-gantry-front

    • Mounts with 2x M3x8 bolts and 2x M3 hex nuts on backside (should be already installed by now)
    • Make sure each limit switch clicks and feels normal when actuated

  • Install idler-pulley onto x-gantry-front

    • Use 1x M5x25 bolt and torque with a 4mm hex driver
    • Check that the pulley can rotate freely without resistance
    • Check that the pulley can only rotate - it should not be able to move up and down if the bolt is tightened correctly

  • Prepare z-belt-subassembly

    • Prepare z-gantry-backplate-left
    • Drill out the limit switch striker bolt hole on z-gantry-backplate-left with a 2.5mm drill bit

    • Install an M3x16 Flathead bolt into z-gantry-backplate-left to a depth that roughly matches the image shown below

      • This screw depth will be precisely in later steps

    • Place a gt2-belt-loop onto the z-belt-alignment-jig

    • Place z-gantry-backplate-left and z-gantry-backplate-right onto the z-belt-alignment-jig to align them correctly on the gt2-belt-loop
    • Twist z-gantry-backplate-left upwards to pull the completed z-belt-subassembly off of the z-belt-alignment-jig
    • Use a dull knife or other tool to push the gt2-belt-loop all the way down into the cavity of each z-ganry-backplate
  • Set timing-pulley height on NEMA 17 stepper motor shaft with jig

    • The 1st set screw tightened  must contact the flat region of the NEMA 17 motor’s shaft

      • Tighten both set screws to 0.4 N/M

  • Install NEMA 17 stepper motor and belts onto the x-gantry-front subassembly

    • Begin by placing the gt2-belt-loop w/attached z-gantry-backplates onto the x-gantry-front subassembly

    • The z-gantry-backplate-right should fit over the right linear rail’s carriage, and the same goes for the left side

    • Install the NEMA 17 stepper motor by angling it into the belt-loop

    • The limit switch connector will be at a 45degree angle from  the z-axis stepper motor’s connector when everything is in the proper position.

    • Bolt NEMA 17 stepper motor onto x-gantry-front with 4x M3x8 bolts

    • Leave the bolts loose for now

    • Tension belt-loop by pulling the stepper motor upwards before tightening its mounting bolts to 0.5 N/M

      • The belts should feel much firmer now - to test manually move the z-axis back and forth while inspecting the belts for sag when changing directions
      • You should be able to pluck the belt like a bass string

  • Attach z-gantry-left and z-gantry-right onto each respective linear rail carriages + z-gantry-backplate with 4x M3x8 bolts per side

    • Align each z-gantry to be parallel with the linear-rail by lightly pressing it outward with your hand, away from the mid-plane of the x-gantry-subassembly
      • As these bolts are tightend ensure that the z-gantry doesn’t collide with the z-idler’s bolt head
    • Tighten bolts to 0.3 N/M, moving in a star pattern

  • Prepare pneumatic-toolhead-assembly

    • Install a nozzle-holder and rotary-pneumatic-adapter onto NEMA11-hollow-shaft-stepper

      • Use a torque driver w/custom rotary-pneumatic-adapter-socket and 8mm wrench to tighten these components onto the motor shaft
      • Set the torque driver to 0.5 N/M for this step
      • Use the 8mm wrench to hold the nozzle-holder stationary while applying torque from the rotary-pneumatic-adapterside
      • The rotary-pneumatic-adapter should be installed closer to the motor's cable connector

    • Install 2x pneumatic-toolhead-assembly onto x-gantry-front-subassembly

    • Bolt pneumatic-toolhead-assembly onto left side z-ganty

      • Attach with 4x M2.5x8 bolts
      • Torque each bolt to 0.3 N/M

    • Repeat above process to attach a pneumatic-toolhead-assembly to the right side z-gantry

X-gantry final assembly

  • Precut GT2 belt to ### length
  • Run gt2-belt through x-gantry-linear axis and connect both ends to x-gantry-back

  • Fully depress the x-axis belt tensioner arm before tightening down the belt with 2x belt-clamps with 2x M5x10mm socket head screws per clamp.

  • Use brass bar to route the belt through the extrusion and ends of the axis

  • Install x-gantry-front-subassembly onto x-gantry-linear-axis, connecting it to previously installed x-gantry-back

  • Step #1 - Hold the x-gantry-back subassembly against the x-gantry-linear-axis subassembly for the following steps to happen easier
  • Step #2A - Fully insert 2x M5x40 bolts through the upper counterbored M5 bores in x-gantry-front
  • Step #2B - Happening basically simultaneously with the previous step, align 2x roller-space and 2x v-wheels onto the previously inserted M5x40 bolts

  • Step #3 - Move the x-gantry-front-subassembly backward into the x-gantry-back-subassembly, paying attention to keeping the upper 2x v-wheels aligned on the x-gantry-linear-axis’s 2020-v-groove extrusion


Rotate everything upside down for the following steps

  • Step #4A - Lower 2x v-wheels up until they rest loosely against the 2020 v-groove extrusion, they should also each be aligned so that each wheel is concentric to the raised nubs on the x-gantry’s tensioner-bars.

  • Note that the 2x tensioner-bar pieces may not be vertically aligned very well by this point, so this process may be tricky

  • Step #4B -

    • Adjust the vertical alignment of the 2x tensioner-bar pieces

    • This is done by tightening or loosening the 4x M3x30 adjustment bolts until you can peer straight through the lower counterbored M5 bores in x-gantry-front and past the hex-nut slot found on x-grant-back

    • This may take a few minutes so be patient!
    • Tighten and loosen all 4x M3x30 bolts as a set, taking care to never make a single bolt more than a few turns away from any other bolt

    • Fully insert 2x M5x40 bolts into the lower counterbored M5 bores in x-gantry-front, through both v-wheels, and stopping within two hex-nut slots found on x-gantry-back

    • Manipulate the z-gantry pieces as needed to avoid interference with the bolts

    • Tension x-gantry v-wheels and x-axis belt tensioner arm

    • Tighten the 4x M3x30 bolts until the toolhead-assembly can smoothly move along the x-gantry-linear-axis, without resistance

    • Grab the toolhead-assembly and try twisting it in many directions, if you feel any play or looseness tighten the appropriate M3x30 bolts until the play dissipates

    • Tighten the 2x lower M5x40 bolts to 0.1 N/M to lock-in the calibrated v-wheel tension
    • Tension the belt to 0.03 N/M ** need to confirm **

Test x-gantry on Gundam jig

  • Ensure that the Gundam motherboard is unplugged from 24vDC power
  • Check that the x-gantry fits correctly on the x-gantry-spacer-jig
  • Slide a bolt into the x-gantry on either side of x-gantry-spacer-jig to prevent it from falling during testing
  • Bolt down the test jig’s drag-chain onto x-gantry-back-subassembly with 2x M5x16 bolts
  • Connect the test jig’s z-limit-switch, x-motor, and z-motor cables to the x-gantry being tested on the x-gantry-spacer-jig
  • Connect the Gundam motherboard to 24vDC power and then press reset on the motherboard
  • Connect the motherboard to the Gundam test software
  • Begin testing the x-gantry by running various macros

  • Check X-Home

    • If the toolhead is moving very slow, the stepper drivers may not have initialized properly - try restarting the motherboard again
  • Check X-Movement Speed

    • Ensure that no weird sounds are heard, if so consult with team for debugging steps
    • Adjust the tightness of the belts and each tensioner-bar as needed to pass this test
  • Test Z-Home

    • Check that the z-belt is adequately tensioned and adjust if necessary - you shouldn’t be able to twist the belt too much
    • Adjust the M3x16 bolt either up or down, if needed, provided the z-gantries are not aligned vertically after homing,

    • This can be checked by sliding a brass shim across the top of the motor while checking to see if it sits higher/lower than the top surface of the adjacent motor

    • Repeat this test and continue adjusting the M3x16 bolt until the alignment appears to be perfect

  • Test Z-Movement Speed

If issues arrise, continue rerunning tests and reworking the x-gantry

Once everything is passing, proceed with the following steps

  • Remove x-gantry from Gundam
    • Disconnect Gundam motherboard from 24vDC power
    • Unplug the test jig’s z-limit-switch, x-motor, and z-motor cables from the x-gantry being tested on the x-gantry-spacer-jig
    • Unscrew the drag-chain mounting hardware from the x-gantry being tested on the x-gantry-spacer-jig
    • Remove the 2 M5x25 bolts used initially for keeping the x-gantry from falling off the x-gantry-spacer-jig

Install top-camera-assembly

  • Install top-camera and Light subassembly onto x-gantry

    • Use two M3x14mm screws to mount the top-camera and Light subassembly onto the back of the X Gantry Back.

QC Checklist

Inspect the completed x-gantry for the following criteria:

  • GT2-belt has been trimmed to appropriate length (flush on 1 side, ~1/2" - 3/4" on the other)
  • Camera is installed with two bolts
  • Camera lens cap is present
  • The wire connectors on both NEMA-11-stepper-motor units face away from each other, sitting adjacent to their respective cable strain relief points
  • Each nozzle-holder has been lubricated and fit-tested with a nozzle
  • Z-belt-loop feels appropriately tensioned when plucked
  • Each z-gantry moves smoothly when actuated back-and-forth by hand
  • 2x M5-hex-nut are installed in x-gantry-back for use with drag-chain attachment
  • NEMA-17-stepper-motor wire connector faces towards drag-chain mounting location on x-gantry-back
  • Linear-rail is centered atop aluminum-extrusion
  • x-idler-mount and x-motor-mount are secured to 600mm-alu-extrusion with 2x M5x10-bolt per side
  • 2x M5-hex-nut are installed in x-motor-mount for use with the x-motor-cable-guide
  • Tensioner-arm is installed on x-idler-mount in the correct orientation (IE acorn-nut facing touches print)
  • Timing-pulley is tightened down and at proper height
  • GT2-belt lays flat and is roughly centered in the 600mm-alu-extrusion channels
  • GT2-belt has been correctly tensioned
  • X-gantry-toolhead moves smoothly when actuated back and forth by hand

If all checks pass, bring the completed x-gantry to the shelf for peer-review and pack-out.