Maintenance is a critical part of achieving optimal machine operation. The tasks below are especially important for those who use their AltMill 4×8 as a production machine – 8 hours a day, at maximum speeds, everyday.
Just like changing oil in your car, service intervals will ultimately depend on the amount of distance your AltMill has traveled, rather than some arbitrary amount of time.
Schedule
Complete maintenance tasks every 100km of distance run by the linear guide blocks.
- At the highest recommended cutting speed (12,000mm/min or 500 IPM) you would need to re-oil every 140 hours of use
- At a much more reasonable lower cutting speed (6,000mm/min or 250 IPM) you would need to re-oil every 280 hours of use
Since a CNC machine is subject to varying conditions and types of use cases, these recommended numbers should be taken as a general recommendation.
Materials needed
- Mobil Vactra No. 2 oil or 3-in-1 oil
- Lithium grease
- Blunt syringe or pipette
- Grease gun, with an assortment of fittings and at least a 12” length flexible whip hose
- Shop towels
- Scotch Brite
- Soft toothed brush
- Nylon wire brush
Rack lubrication
Linear guides lubrication
Clean – Wipe down the guide rails with shop towel to remove debris. If there is rust, scrub down with Scotch Brite. Jog the machine to access the entire rail for thorough cleaning.
Lubricate – Remove the spindle, spindle mount and Z-plus drag chain arm from the Z-axis gantry. Unfasten the outer button head screw from each linear guide block. Apply the oil using a pipette or syringe to the hole until it flows out. Then refasten the screw. Otherwise, you could instead manually coat the linear guide rails with shop towel.
Jog the machine along the axis to distribute the lubricant.
Ball screw lubrication
Clean – Remove debris from the ball screw by using a soft brush to get into the threads. Make sure you clean the entire ball screw, by jogging the AltMill to another spot.
Lubricate – Apply grease at the zerk fitting, using the grease gun. You should only add a small amount, so 1 squeeze at the gun will be enough. You will need to use a long grease gun fitting and the whip hose
Given the correct hose length and grease gun fitting, you will not need to disassemble the machine unless the fitting is in the wrong orientation.
Once you apply the grease, jog the machine along the axis to distribute it.
Other Maintenance Tasks
In addition, the AltMill 4×8 should be regularly checked for loose parts, irregular sounds and foreign objects including large buildups of dust or chips that could block moving components. Staying alert and noticing any changes to your machine over time will inform your maintenance routine, keeping it in tip top shape.
Spindle Warm-up
For regular upkeep of your spindle, we recommend running a shorter “warm up” g-code, especially if you run your machine in a cold environment or if you hear sounds in the spindle while it is running. This will help redistribute the grease in the bearings.
Just download the file and run it like you run other jobs. The machine will not move, only the spindle will spin a bit. It will take about 10 minutes to complete.