To remove dust and debris, use compressed air to blow out the fans on the printers while they are powered down.
The Workhorse and Mini 2 both have two fans, as shown above.
From the TAZ Workhorse Manual:
"Wipe the smooth steel rods with a clean cloth or paper towel. The linear bushings leave a solid lubricant that builds up over time. Hearing squeaking noises while the printer is printing is likely a sign that the smooth rods need to be cleaned. NOTE: Never apply any lubricant or cleaning agent to the smooth rods; the bushings are self-lubricating."
This process is the same for the Mini 2 as well. Each printer has eight smooth rods; two for the X-axis, two for the Y-axis, and two on each side of the Z-axis.
Check the belt tension for the Y and X-axis belts.
You should feel resistance when pressing down on the midpoint of the belt. If you see visible sagging or it is very easy to press both sides of the belt together, they may need tightening. You can also try moving the tool head and bed to make sure each is able to move smoothly along the axis. If they cannot, that is another sign the belt tension needs adjusting.
Instructions from the TAZ Workhorse manual:
"Over long periods or after extensive relocating of the printer you may need to re-tighten the belts on your 3D printer. For the X-axis, using the 2.5mm hex driver, loosen one of the belt clamps. The belts clamps are located on the X-axis carriage. To loosen the belt clamp, loosen the M3 screws on the clamp. Using the needle nose pliers, pull the belt tight. While holding the belt tight, tighten down the M3 screw.
The Y-axis belt can be tightened using the same steps as the X-axis using the belt clamps found on the bottom of the Y-axis plate. Make sure not to over tighten the belts as this can cause binding and prevent full movement.
The Z axis belts used are continuous, and should not need tensioning. If they do require tensioning, use your M5 driver to tighten the screw on the top of your Z uppers."
Image courtesy of LulzBot
Use step 15 from this LulzBot guide to tighten the X-axis belt.
Use step 16 from this LulzBot guide to tighten the Y-axis belt.