Pinch Points and Crushing Hazards:
It is highly encouraged that you approach the H-Series machine with the methodical care of a machinist. The combination of ballscrews and high-torque Nema 23 stepper motors result in sufficient force on all axes to cause serious bodily injury to you and serious damage to the machine. With typical 3D printers, the fixturing setup is always the same: an empty build volume with a flat bed. However, when vises, varying stock geometries, rotary axes, and other complicated setups are used, the potential for crashes greatly increases. In both the mechanical design and controls functionality, we are attempting to minimize these risks, but in the end, a highly versatile and useful machine cannot be made hazard-free.
The major pinch point and crushing hazard occurs with z-axis motion. It is very important to verify clearances before starting any movement cycle. Keep your hands (and other body parts) out of the build volume any time the machine is active. Use extra caution when touching off tools and when using shim stock as a feeler gauge. During probing cycles and certain other operations, the z-axis motor current is reduced to minimize potential damage, however these reduced forces are still dangerous. Additional pinch points can be found where the tools clear the recess in the Z-axis arm (as shown in the image below). Keep tools and body parts clear of these regions when the machine is powered.
Multiple regions of the machine have high temperature components that are accessible to the user. The hot ends of the extruders are the most dangerous burn hazards. These components can be as hot as 300°C with molten plastic at the tip. With the turret design, these nozzles protrude radially outward, so it is easy to come into contact with them if care isn’t taken. The heated-build-plate (max temperature of 110°C, limited with an internal thermostat) also present burn hazards to the careless user.
The H-Series machine generally uses low voltages: 3.3-5VDC for signals, 24VDC for the main drive components and extruders, 48VDC for the bed heater and spindle drives. These circuits present minimal risk of electrical shock to the user. However, there are small areas where mains power is routed to the power supplies (although these areas are covered). For any maintenance or assembly work that requires interaction with these components, Diabase Engineering will provide explicit and specific work instructions. As a general rule, the machine should be powered down and unplugged anytime the controls cabinet door is opened.
This video also addresses some of the primary safety concerns (on the H4 version of the machine):
When starting a new job on the machine, it is always a good practice have a hand hover over the E-stop as to ensure that the machine is configured properly for the current setup. This practice can help reduce crashes and ensure the safety of the operator.