The Fuse Blast requires a steady supply of compressed air in order to perform its core functions of blasting, rinsing printed parts, and rinsing the blasting chamber. If the compressed air supply is insufficient for the selected blasting cycle, the Fuse Blast displays Error 2.7.6: Low Air Supply Pressure and the performance of the blast cycle may be lower than expected.

As of firmware version 1.0.2, Fuse Blast units will first pause the cycle it is attempting, allowing the compressed air supply to recharge, before stopping and displaying an error message. If your blasting cycles are frequently pausing, this may also indicate that the compressed air supply is insufficient for the set blast cycle.

There are a number of factors that can influence the pressure and quantity of the air supplied by an air compressor, including compressor power, reservoir size, tubing length, tubing inner diameter, fittings used, other tools drawing on the compressed air supply, and more. This document provides troubleshooting steps for common issues with your Fuse Blast’s air supply.

• Error 2.7.6: Low Air Supply Pressure displayed on the Fuse Blast touchscreen
• Worse than expected part finish and cleanliness
• Uneven media spray from blast gun
• Blasting cycles pausing frequently, allowing for the compressor to recharge

The possible causes of low pressure issues, in approximate order of likelihood, are:

• Blasting cycle pressure is set too high for the capacity of the compressed air supply
• Blasting cycle time is set for too long for the capacity of the compressed air supply
• Air compressor does not meet recommended specifications
• Compressed air supply tubing is too long
• Compressed air supply tubing is too narrow
• Fittings in air supply introducing pressure loss
• Leaks in air supply
• Internal leaks in the Fuse Blast pneumatic tubing

Update firmware and adjust Adaptive Airflow settings

As of firmware version 1.0.2, Fuse Blast automatically manages airflow interruptions with Adaptive Airflow. Adaptive Airflow monitors the inlet supply pressure and pauses the cleaning cycle, allowing the compressed air supply to recharge without aborting the procedure. Update the firmware to version 1.0.2 to access Adaptive Airflow.

While the default settings are sufficient for cleaning most printed parts, users can configure the Adapted Airflow settings to best suit their blasting needs.

To change the Adaptive Airflow settings:

1. Update the firmware to version 1.0.2 or newer.
2. Tap the gear icon on the bottom left of the Fuse Blast’s Home screen. The Settings menu appears.
3. Tap Maintenance > Adaptive Airflow. The Adaptive Airflow screen appears.
4. Select your desired recharge time:
   1. Recharge Timer: This sets the amount of time the Fuse Blast waits for the compressed air supply to reach the required pressure to continue the cycle. Drag the slider left or right to set the length of recovery time to recharge the air compressor in the event of a supply interruption. If the compressed air supply does not reach the required pressure before the timer expires, the Fuse Blast stops the cleaning cycle and displays Error 7.6.
   2. Fill Timer: This sets the amount of time the Fuse Blast waits after the compressed air supply reaches the required pressure before continuing. For example, this allows time for a compressed air tank to fill enough so that the supply pressure does not drop immediately when the cycle resumes. Drag the slider left or right to set the time given to refill the compressor once it has met the cleaning cycle required pressure.

Determine during which blasting cycle stage the issue occurs

A normal blasting cycle has three stages: blasting, chamber rinse, and part rinse, in that order. Using the standard blasting preset settings, part rinse demands the most air, as at least 13.4 SCFM (379.4 SLPM) must be supplied for at least three minutes.

1. Using the manual Fuse Blast pedals, run the blast gun at the desired pressure and time settings (30 psi for 10 minutes is recommended for a standard blast cycle). Note any drop in pressure readings at the compressor or error messages on the Fuse Blast.
2. Using the manual Fuse Blast pedals, run the part rinse at the desired pressure and time settings (40 psi for 3 minutes is recommended for a standard blast cycle). Note any drop in pressure readings at the compressor or error messages on the Fuse Blast.
3. If the Fuse Blast did not display an error message during the previous steps, run a rinse-only cycle and note any drop in pressure readings at the compressor or error messages on the Fuse Blast during the chamber rinse cycle. The chamber rinse can be identified by the movement of the thin air whip tubes around the periphery of the blasting chamber.

Determine the maximum pressure that can be sustained by your compressed air supply

1. Once you have determined when the low pressure issue occurs, gradually decrease the pressure setting for each cycle until the compressed air supply can meet the demand for the time required. Note that as air pressure is decreased, the cycle time may need to be increased to achieve equivalent part finish.
2. If the error occurs during the blast stage, consider installing the provided 3 mm blast orifice to achieve greater pressure values with less air consumption.
3. Once you have found a set of effective blast cycle settings, save them as a Custom preset.
4. Using the Custom cycle preset, run an automatic blast cycle and adjust further as needed.

Evaluate the compressed air supply

1. Ensure your air compressor meets the requirements for the settings being used. If the air compressor does not meet the minimum requirements, follow the instructions above to minimize air consumption or source a more powerful compressor. Formlabs’ recommendations can be found here.
2. If your compressor meets the minimum requirements for your blast cycle settings, there may be loss introduced between the compressor and the Fuse Blast:
   1. Check the length of the tubing. An excessively long supply tube will introduce pressure loss. For the most efficient use of your compressor, keep the supply tubing between the Fuse Blast and the air compressor as short as possible.
   2. Check the inner diameter of the tubing. Narrow tubing may not be able to supply enough air to the Fuse Blast. Formlabs recommends using tubing with at least a ⅜” (10 mm) internal diameter.
   3. Check the fittings in the air supply. Any fittings, such as elbows, tees, valves, and adaptors, will introduce pressure loss. Remove unnecessary fittings to reduce that pressure loss.
   4. Check any other tools drawing from your air supply. Any other tools using compressed air will draw down from your air compressor when used at the same time as your Fuse Blast.

Replace the blast orifice

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 replacing the 4 mm blast orifice and installing the 3 mm blast orifice if you have an air compressor that does not supply enough pressure to adequately clean parts. Measure the inner diameter of the spare blast orifice that came with your Fuse Blast to determine which is currently installed.

Check for leaks

If your compressed air supply is sufficient, there may be leaks in your supply tubing or inside the Fuse Blast unit.

1. Run a blast cycle and listen for any air escaping. If there are leaks in your air supply tubing, resolve these and retest the system.
2. If there are no leaks in the air supply tubing or if leaking air can be heard from inside the Fuse Blast, there may be a leak in your internal pneumatic tubing. Contact Formlabs Support for assistance inspect the internal tubing of your Fuse Blast unit.