The Fuse Blast ships with two blast orifice sizes: a 3 mm orifice and a 4 mm orifice. Early Fuse Blast units shipped with the 4 mm blast orifice preinstalled. All subsequent units shipped with the 3 mm blast orifice preinstalled. Formlabs recommends using the 3 mm blast orifice if you have an air compressor that does not supply enough pressure to adequately clean parts with the standard 4 mm orifice.

The 3 mm orifice and the 4 mm look similar from the exterior. Measure the inner diameter of the spare blast orifice that came with your Fuse Blast to determine which is currently installed.

Made by Formlabs

• Replacement blast orifice

Made by third parties

• 3 mm hex driver
• T20 Torx driver

To remove the currently-installed blast orifice:

1. Turn off and unplug the Fuse Blast.
2. Unlatch and open the blasting chamber door.
3. Push the retention ring at the back of the blast gun towards the blast gun body. While pressing on the ring, separate the clear hose from the blast gun.

4. Rotate the blast arm so you can access the left side of the blast gun. Locate the four screws securing the blast gun to the blast arm.

5. Using a T20 Torx driver, unscrew and remove the four screws. Take care not to damage the grounding wire attached to one of the screws. Set the screws aside.

6. Separate the blast gun from the blast arm.
7. Rotate the blast gun so you can access its right side. Locate the set screw securing the blast orifice.

8. Using a 3 mm hex driver, loosen but do not remove the set screw.

9. Slide the blast orifice out of the back of the blast gun.

After removing the previously-installed blast orifice, install the replacement orifice.

To install the blast orifice:

1. Insert the blast orifice into the back of the blast gun. Push the blast orifice forward until it bottoms out against the back of the blast gun.
2. Using a 3 mm hex driver, tighten the blast orifice set screw until snug.
3. Align the four screw holes in the left side of the blast gun with the corresponding holes in the blast arm.
4. Place the grounding wire on one of the T20 screws and loosely thread into one of the four screw holes. Thread the remaining three screws into their screw holes. Using a T20 Torx driver, tighten until snug.
5. Firmly press the clear tube into the port on the back of the blast gun.
6. Close and latch the blasting chamber door.
7. Connect the Fuse Blast to power and turn the machine on.
8. Test the blast gun with the new blast orifice.