How to Replace a Nova Z Axis belt

Preface: This article is basically a copy paste of the attached PDF that covers how to replace the Z axis belt on your Nova series laser. It is currently a work in progress.

This work should be performed with the machine powered off and unplugged. Perform this work at your own risk.

Before you start to do this, please keep all screws or parts after you remove them. This is a fairly lengthy install process, so allot the proper amount of time to get it done.

Tools You will need:

12mm Gauge Block

Metric Allen Wrench Set - 3mm and 4mm

Calipers

Snap Ring Removal Tool (Was included in toolbox)

Sharpie

Camera

Knife/Heavy Duty Scissors

Prework:

-Remove front Lower Machine Door

-Remove the honeycomb Bed and Knives 

-Remove the Crumb Tray(s) (Good time to dump and clean)

-Remove the Belt Covers (If applicable)

-Mark the position of the tensioners and screw rod mounting brackets with the Sharpie

-Take pictures of the belt routing with your camera

Belt Removal:

Since the belt is in need of replacement, the easiest removal method would be to cut belt and remove it. This will eliminate the belt tension on the tensioner pulleys and ease the removal of the tension blocks in preparation of the belt replacement.

With the belt removed:

1. Remove 3 tensioners and then use the snap ring pliers to remove the snap ring to release the bearing and pulley from the tensioner bracket

Left Side Tensioners	Right Side Tensioner

Tensioner Block Assembly	Snap Ring and Bearing Removed	Components removed from Tensioner Bracket

Example video of using snap ring pliers with snap rings.

2. Remove the Knife Support Bar from the front and rear Screw Rods

3. Unbolt the 4 screw rod plates (upper and lower mounting brackets).

4. Loosen the bolts for the Z Bed Honeycomb Motor 

Installation:

1. Remove 4 Screws Rod from Machine 

2. Place belt in the machine and spread it out. 

3. Place 4 Screw Rods Back into machine with the belt on the outside of the pulleys. Screw into place but not tight

4. Install tensioners back onto belt, re-insert the Snap Ring to hold the tensioner pulley in each tension block. Pay attention to the orientation of the belt and that the tensioner contacts the smooth side of the belt

5. Thread the new belt around the Z motor. Tighten the Z motor down to the base.

6. Reinstall the screw rod mounting bases (do not fully tighten the bolts). Find a piece of wood or aluminum block, the

thickness should be 12mm.Then put the aluminum block to the inside of the bar. See

below picture.

Note: All 4 screw rods must be calibrated with this aluminum block.

7. Tighten the bolts the fours screw rods, for the two screw rods at the front side. When you tighten the blue

mounting blocks, be sure to measure the distance between the block and machine housing as shown.

The distance of the bottom side is 111mm.

The distance of the up side is 105mm.

Note: 0.5-2mm error is acceptable.

8. Put the belt inside the three blue tension bases and reinstall the tensioner pulleys.  Then tighten the one on the right. You do not have to make it the belt super snug, we will be adjusting the Z bed later on and will need to remove tension to do so.

9. Rotate the gear of the screw rod to rise up the sliver holder, other corners also need to

be raised up.

10. Put the knife holder on and tight it slightly. Make sure it’s level and then tight it.

11. Find a cube (the cube shown is 45mm), and put it to four corners for measure the

distance between the knife holder is the same. If the distance of which corner is different,

please rotate the gear of the screw rod to adjust. Move the laser head to each of the four corners and

repeat these steps until the distance is the same. 

12. Put two knifes on the knife holder, one put the left side, the other put the right side. Make

sure there has a little space between the knife and the knife holder (about 2-3mm.)

13. Tight the screws of knifes holder.

14. Tighten the blue tensioner on the right side and one of two blue tensioners on the left side slightly.

15. Pull the belt from right side to left side, then fix the last blue tensioners. Please note: do not

rotate the gear of the screws rod during this process. If the gear is rotated, you will need to

adjust bed level again. 

16. Tight all blue tensioners and check the tension of belt. It should be snug but not banjo tight. 

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