Millit works as follows:
- The user creates a new project by specifying, among other parameters, in which sheet thickness and dimensions the base material is available.
- The 3D computer model of the part is then loaded from a file that has been created with a CAD program and stored as the body for this project.
- After the body has been rotated into a position designated by the user, it is cut into horizontal layers along the vertical axis, so that the resulting components no longer show any undercuts and so that
their thickness does not exceed the thickness of the sheet material. In that way, each single component can be milled out of the base material by dual-sided milling. After the automatic slicing process the
user can check the created components using a 3D viewer and correct any undesirable slices by manual action.
- To ensure that later the components can be correctly positioned, borings can be added to the components' cutting surfaces in the computer model, which are facing each other when two components are positioned
on top of each other. These borings will later be created with the milling machine and will hold fitting pins.
- The components are laid out on the sheet material as close to each other as possible, so that after the cut out of the components the left over sheet material forms a frame around and between them. For all
these frames, a computer model is automatically created and assigned to the project. To achieve this, the user calls up a program function which automatically creates all the frames and places the
components within them. Finally, the user is able to optimize manually - supported by the 3D display in the viewer - by adding components to frames, rotating or moving the components and by changing the
size of the frames.
- Bridges are added to the computer model of the frames, which connect the components to the frame and remain in place during the milling process. Later, when milling, the entire frames will be clamped, not
just the individual components. When creating frames automatically, four bridges are assigned to each component, which the user later on manually can move, remove or add more of them. Once again, he is
supported by the 3D viewer and various options for the bridges (connection method to the component, height, width, etc.).
- The base material is always outfitted with two system borings which are located on the center axis (turn-over axis for milling the backside) where the frame's edge remains.
- NC programs are automatically generated from the component, frame and bridge computer model, in order to control milling of the front and back sides of the base material, whereby the turning of the frames
over the axis of the connecting line of the system borings is taken into consideration. NC programs also can be generated for the preparation of the sheet material and the application of the system
borings. The necessary technical information for the generation of the NC programs (machine parameters, tools, step widths, speeds, milling strategies, etc.) is specified by the user and stored for the
project or for the individual frames. Frequently used machine and tool parameters can be stored in libraries, which are part of the program.
- The individual sheets are clamped on the milling machine by being set with their system borings onto two pins located on the table of the machine, they are then milled on one side, removed from the pins,
turned over, set on the pins again, and finally milled on the other side as well. The milling machine carves the components' geometry out of the sheets, bores the holes for the fitting pins and
(optionally) removes the bridges, leaving only a small remainder, which just barely holds the components in their frames.
- After milling the frames, the bridges or what is left of them are cut off and the components removed. The leftover material from the bridges is then manually ground off.
- Fitting pins are inserted into the components' borings on one side, glue or solder is applied to the mating surfaces, the components are joined and the glue is allowed to harden or the connection is soldered.
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