The parallel lathe is a machine, also considered a tool, that allows transforming the dimensions and shapes of any solid piece. This transformation process is achieved through the rotation of the solid piece around the symmetrical axis of the desired shape, removing material peripherally in the form of chips. This is how a parallel lathe works.
How does a parallel lathe work?
The system of the parallel lathe is based on a headstock in which a spindle rotates, two parallel guides, one longitudinal and the other transverse to the spindle. On the spindle's shaft, the universal chuck (can be a flat plate or with three and four jaws) is installed. They are used to adjust and center the piece to be machined and indicate the rotational movement that the electric motor will perform.
The parallel lathe is one of the most useful and widely used machine tools in the industry. Among the advantages of the parallel lathe, its easy handling and versatility stand out, as its parts can be prepared in a short time and easily. This machine is used to perform a multitude of tasks with maximum effectiveness, such as:
- Cylindrical turning
- Facing
- Taper turning
- Thread cutting
- Parting
- Metal cutting
- Shape cutting
What are the parts of a parallel lathe?
The parallel lathe is composed of 4 parts: headstock assembly, bed, carriage, and tailstock assembly.
Headstock assembly
The piece is permanently attached to the bed on the left side of the lathe. It also includes the headstock spindle, which rotates with the help of pulleys. The function of the spindle is to center the target piece and make it rotate. The precision of work with a lathe depends on the spindle's rotational axis that centers the piece, which must be manufactured with the utmost care.
Bed
It constitutes the base of the lathe and is the part responsible for supporting all the components that make it up. The quality of the guides depends on the construction materials used by the manufacturer. In this sense, more economical lathes are distinguished by having less reinforced or non-hardened guides.
In the market, replaceable linear guides can be found, while other manufacturers use hardened cast iron guides that are fundamental in the bed.
Carriage
It is the part responsible for controlling the cutting tool and is composed of 5 different parts:
- Panel attached to the carriage support: it is suspended at the front of the bed
- Cross-slide support: this cast piece slides over the guides and adjusts to the bed
- Compound rest: it is located at the top of the cross-slide
- The cross-slide: is situated above the main carriage
-
The post for the wedge and washer, which slide over a T-slot on the top of the support
Safety elements of the parallel lathe
The parallel lathe features a transparent guard and a micro switch used preventively against projections, and with push buttons that allow emergency stops, etc. Additionally, the belts, pulleys, and toothed wheels of the machine are protected with guards.
Preventive measures for using the parallel lathe
Now that you know how a parallel lathe works, before starting the turning work, it is very important to perform the following checks:
- The machine must be connected to a differential switch with its corresponding ground point. Additionally, it is advisable that the protective layers of the transmissions and gears have switches installed in series, as this prevents the lathe from starting when the protective covers are not closed.
- The piece to be turned must be in a correct position and securely fastened so that the movement encounters no obstacles.
- The chuck and the lock must be correctly positioned.
- Ensure that the fastening screws are properly tightened.
- Remove the chuck adjustment key..
- The locking lever must be well secured.
- The transparent screen for protection against chip projections must be properly positioned.
- If the turning work is performed on long bars, it should be verified that the bar is fully covered by a protection-guide.
- If a tailstock is incorporated in the turning process, confirm that it is well anchored to the bed and that the lever that locks the spindle is properly tightened.
- Check that there are no tools or parts left on the lathe that could be ejected during the process.
- The protective cover of the chuck must be properly positioned.
- During turning, the person in charge must position themselves safely and as far away as possible from the rotating parts. Hands must be kept on the parallel lathe handwheels and never on the bed, tailstock, carriage, or the workpiece.
- All verification measures must be carried out with the lathe turned off, especially the following:
- Tool change
- Piece fastening
- Cleaning
- Finish measurement
- Situation of the cutting fluid (lubricant/coolant)
The set of the above information is applicable to all lathes, but primarily to manual or conventional lathes. CNC lathes, by working automatically once programmed, must and usually have fully enclosed guards and do not operate until the door is completely closed, allowing for much safer machining operations.
