Mill-lathe machines represent the best features of lathes and milling machines, enabling the rapid production of complex parts that would otherwise be less efficient if manufactured using multiple operations on different machines.
Generally speaking, lathes are divided into different types such as 2-axis CNC, 3-axis CNC, 4-axis CNC and 5-axis CNC. Choose the correct type for lathe processing according to the product to be processed.
XYZ is a linear axis where Z is aligned with the machine tool spindle.
ABC is respectively an axis of rotation around XYZ.
UVW lie along the linear axes parallel to XYZ, respectively.
This is done via the spindle or rotating C-axis.
When the spindle stops rotating, tiny servo motors in the turret-mounted tool operate, transforming the lathe into a traditional milling machine. Positioning and contouring movements will be allowed with servo motors to maintain position. Contour cutting can be performed in this manner using the C axis for simultaneous XYZ movement.
The secret of these machines is twofold:
First, they are able to treat the main axis as another axis, called the C axis. This allows well-positioned parts to be positioned at any angle.
Second, they have dynamic tools. Instead of a regular lathe tool in the turret position, there is a small motorized spindle that can accommodate an end mill, twist drill, saw, or whatever is needed.
How to convert a spindle to a C axis indexer?
An obvious answer used in many machines is to use a servo as the spindle motor. Think of it as a brute force approach.
Another method is to use auxiliary servos that can be engaged or disengaged. Here is such a configuration on an Emco lathe:
C-axis lathe mechanical equipment
We can see many interesting features in the photo:
– Features a collet pull mechanism to open or close the collet or chuck.
– Has a toothed gear and hydraulic spindle lock. Considerable lateral forces can be exerted during C-axis operation, and it is often important to be able to lock the axis when this occurs.
– The spindle is driven by several large multi-groove belts.
– There is an auxiliary spindle indexing servo. It’s not visible in the photo, but it’s the encoder (or possibly the derailleur that engages/disengages it) and the toothed belt system that drives the axle.
The construction is very simple. This is another trick with a C-axis auxiliary servo:
The C-axis of the lathe uses a gear-driven secondary servo. Note the disc brake used to lock the axle.
The gear driven C axis makes me wonder how to avoid backlash? Here’s another one for a toothed belt drive:
When the spindle drive is running, some sort of clutch mechanism is used to decouple the position servo from the C-axis.
Motorized tools: When the tool holder becomes a milling spindle
Most power tools include a coupler that allows the turret to drive the power tool spindle:
Angular head for power tools: power coupler on the right, tool holder on the left, etc.
A simpler method for lightweight workpieces and tool sets is to use a pneumatic spindle:
Pneumatic spindle on combined lathe…
Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.
