Gantry Replacement: CMC 8500

NEVER SKIP AHEAD ON ANY STEP!

• Head appearance may vary from model shown, but the connections are the same.

• Never pull/push on the Drive Shaft to move the Gantry.

• Use the Gantry Arm to move/pick up the Gantry.

• Do not pick up the Head using only the Blade Depth Knob or the Head Cover.

• Pick up the Head by holding the “D-Shaped” upper and lower Head Faceplates.

• Follow these instructions if you have a Straight Line Trimmer installed, otherwise skip ahead to Head Removal.

• Turn the shut off valve on the Blue Air Line, and unplug the Blue Air Line before removing the Straight Line Trimmer.

• Turn the bottom locking knob Clockwise to loosen.

• Turn the top locking knob Counter-Clockwise to loosen.

• Slide the Straight Line Trimmer off of the Board and set aside in a safe place.

• Click the Reset Motors Button on the Cut Preview and click OK on the Release Motors prompt.

• Push the Blade Cartridge Release Lever down to eject the Blade Cartridge.

• Turn off the air.

• Remove the Gantry Cover by unscrewing the screws that holds it in place and set aside.

• Move the Gantry to the right side of the Board until the Footblock is off the Board.

• Disconnect the Head Power Plug (square connection) from the Head Grabber Arm.

• Disconnect the air to the Head by untwisting the two air fittings.

• Remove the two 5/32” screws and set aside.

• Roll the Head down the Gantry until it rolls off the Gantry, taking care not to drop it.

NEVER SKIP Ahead ON ANY STEP!

• Remove the front right 3/16” Stop Screw from the Stop Plate on the left bottom rail (located on the top of the bottom Board Rail) and set aside.

• Loosen the back left screw and T-Nut and slide the Stop Plate to the end of the Board Rail to remove.

• If your model only has a Stop Screw without the Stop Plate, remove the Stop Screw.

• Remove the 5/32” Allen screws and washers from the lower Gantry Plate.

• Disconnect the Air Lines to the Gantry by untwisting the air fittings.

• Disconnect the Board Cable by turning the locking ring until it comes away from the Gantry.

Look for Red Dots (only these screws are to be adjusted).

• Loosen one full turn only the 3/16” Allen Belt Tensioner Screw from the right bottom side of the lower Board Rail marked with a red dot.

• Only loosen it enough so that there is some movement in the Belt Tensioner; about one full turn.

WARNING: Make sure you do not over loosen this screw. One full turn is usually sufficient.

• The Belt Tensioner Springs should be visible.

• Locate the Belt Tensioner Hole on the end of the Belt Tensioner.

• Place the 5/32” Allen screw and washer we removed from the lower Gantry Plate into the Belt Tensioner Hole.

• Tighten the Allen screw until the Belt Tensioner is flush with the Board Rail and the springs are not visible.

• Go back and tighten the 3/16” Allen Belt Tensioner Screw on the right bottom side of the lower Board Rail marked with a red dot.

• Lift the Drive Belt End out of the Belt Tensioner Slot.

• Pushing the Drive Belt End to the right may assist in getting a hold of it.

• Wind up the Drive Belt and rubberband it.

• Repeat these steps with the upper Board Rail.

• Move the Gantry to the left to dislodge the Belt Anchors.

• The Belt Anchors are sunk into the left ends of the Board Rails and are attached to the Drive Belts.

• Lay the Belt Anchors over the Drive Belts and rubberband them together.

• Hold the Gantry on the bottom and along the Gantry Arm and gently roll the Gantry off the rails on the left side of the Board and set aside.

• The Gantry only weights about 30 lbs, but it is large and awkward, so having a second person standing in front of the CMC helping may be beneficial.

• Before installation, look at the bottom set of Gantry Wheels.

• The bottom Gantry Wheels are spring-loaded, the top Gantry Wheels are on a center-pivot.

• Move the top set of Gantry Wheels as needed for ease of installation (picture shows the Gantry being put on the Board Rail from the back).

• Before installation, look at the top set of Gantry Wheels.

• Both sets of Gantry Wheels are spring-loaded.

• The Gantry Wheels may need to be eased over the Board Rails (picture shows the Gantry being put on the Board Rail from the back).

• Hold the Gantry near the left side of the CMC and line up the upper then lower Gantry Wheels to the center channel of the Board Rails.

• NOTE: Installation is easier if you line up the upper Gantry Wheels first, then slide the lower Gantry Wheels onto the Board Rail. Sometimes having a second person for this step helps.

• Carefully ease the Gantry onto the left side of the Board Rails, taking care that all the Gantry Wheels line up.

• Make sure that the Drive Belt lies within the channel on either side of the Gantry and is not pinched between the Gantry and the Board Rail.

• Roll the Gantry past where the Stop Plate was removed.

• Slide in the Stop Plate from the end of the Board Rail.

• Replace the 3/16” Stop Screw into the Stop Plate and into the left bottom Board Rail.

• If you only have the Stop Screw, replace the Stop Screw.

• Roll the Gantry so it lines up to the Stop Plate.

• Loosely tighten the back left Stop Screw, then the front right Stop Screw, repeating until the Stop Plate is secured into position.

• Roll the Gantry to the far right of the Board and back to the left to make sure it moves smoothly.

• Lightly pull the Drive Belt toward the right to take up the slack and pull the Belt Anchor into place flush with the end of the Board Rail.

• Remove the rubberband from the Drive Belt and pull the loose Drive Belt End to the right, making sure that the Drive Belt is not twisted and that the teeth are facing down toward the Board into the Board Rail channel.

• If necessary, rotate the Toothed Pulley so that the red mark is on the top.

• Line up the red mark of the Drive Belt to the red mark of the Toothed Pulley; this may require moving the Gantry a bit in either direction.

• Pull the Drive Belt to the right to take up the slack.

• Do not move the Gantry after the red marks line up.

• Slide the screw of the Belt End into the Belt Tensioner Slot.

• Go back and make sure red lines are still lined up.

• Remove the 5/32” Allen screws and washers from the Belt Tensioner.

• Leave the Gantry where it is.

• Loosen one full turn only the 3/16” Allen Belt Tensioner Screw from the right bottom side of the lower Board Rail marked with a red dot.

WARNING: Make sure you do not over loosen this screw. One full turn is usually sufficient.

• The Belt Tensioner should spring fully into place.

• Repeat steps 1 through 10 with the upper Board Rail.

• Place the two Allen screw and washer into the holes provided on the lower Gantry Plate.

• Place them so that the screw protrudes only slightly from the back of the Gantry Plate.

• Go back and snugly tighten the 3/16” Allen Belt Tensioner Screw from the right bottom side of the lower Board Rail and the right bottom side of the upper Board Rail marked with a red dot.

Carefully align the in-line pins of the Board cable before applying pressure to plug it in. If forced in incorrectly, the CMC will malfunction.

• The Board Cable connects the Gantry on the to the Driver Pack.

• Connect the male end of the Board Cable to the back of the Driver Pack by aligning the pins and turning the locking ring until it seats itself and locks into place.

• Connect the female end of the Board Cable to the back of the Gantry in the same manner.

• Move the Gantry to the far right of the CMC and back to the left to make sure the Board Cable does not get caught on anything.

• If the Board Cable is obstructed, this will affect the cuts.

• Follow the Air Line with the red connector from the top of the Gantry and connect it to the right side of the Air Regulator by inserting the red connector on the end and twisting it into place.

• Follow the Air Line with the blue connector from the top of the Gantry and connect it to the matching blue Air Line on the back of the Board.

• Make sure that none of the Air Lines are crimped.

CAUTION: The Air Regulator is factory-set. Do not make adjustments to it.*

• Move the Gantry to the right edge of the Board.

• Point the Head so that the Footblock faces toward the Board and the Head Wheels are close to the bottom of the Gantry.

• Line up the Head Wheels on the Head to the center channels of the Gantry Arm and ease the Head onto the Gantry.

• Roll the Head up the Gantry until it lines up to the Head Grabber Arm on the right side of the Gantry.

• NOTE: If you are installing the Head and having difficulty getting the Head Wheels onto the Gantry, see “Head Wheel Adjustment” further below.

• Holding the Head in position so that the Head lines up neatly to the Head Grabber Arm, replace the two 5/32” screws, making sure they go into the Head Grabber Arm and into the Head and tighten firmly.

• Connect the air to the Head by twisting the two Air Fittings together, matching colors.