If you have a lathe, you’ll have an easy time cutting, sanding, drilling, or deforming various workpieces. You can either use a wood lathe that works only on wood to either cut, sand, drill or deform wooden workpieces.
Alternatively, you can use a metal lathe that can work on both wooden and metallic workpieces. But It’s mainly for working on harder workpieces like steel, aluminum, or iron.
With the correct type of lathe, you’ll be able to shape or turn the workpiece with ease, removing the material’s outer diameter. What are the types of turning with wood and metal lathe? Read on and understand more.
Types of Turning
1. Straight turning
Straight turning originated in the watch industry, and you can use it to make long slim parts from rod stocks or wires. Here you need to maintain the size of the diameter throughout the workpiece.
Ensure you use the right cutter bits for straight turning. Also, position the workpiece in the cutting tool holder that’s fixed with the tool post. Don’t forget to mount the workpiece well to get an accurate turning operation.
2. Taper turning
Taper turning allows you to shape the workpiece by uniformly changing the diameter from one end to the other. It helps you reduce the workpiece’s diameter from one edge to another, either internally or externally.
You can use three methods to turn tapers using a lathe, which depends on the degree, length, and location of the taper or the number of pieces you expect to do.
If you want to make a taper, you’ll have to put the tool’s cutting edge at the center of the workpiece’s axis. Failure to do so will not give you the right shape, and the rate of taper will be different according to each cutout.
3. Rough turning
If you want to remove bigger stock from a workpiece faster and effectively, use rough turning. But ensure you use the right tool which can work on a heavy chip. Also, the tool’s speed and its amount of feed should be great.
If you’re doing a rough cut on either steel or iron with the scale on its surface, set the tool deeper into the first cut scale. Not doing this will make the scale dull your tool.
Ensure you rough the machine until you’re about to finish the size, then measure the surface on the uneven surface.
Remember, while doing the rough turning, there’s heat production which tends to expand the workpiece and flow out of the live center hole. So be careful while doing this and make necessary adjustments where necessary since it can wear the workpiece.
4. Hard turning
This type of turning is a replacer of grinding operations. You can use it on post-treated parts that have a surface hardness of between 45HRC and 68 HRC. It’s a similar process as soft turning as they share most fundamentals.
If you’re to turn hard steel with PCBN, you’ll require a negative cutting edge without using a cooling fluid, reducing the operations costs.
However, when it’s a conventional lathe that you’re using to turn with a negative angle, be ready to experience vibrations that interfere with the workpiece form and roughness.
You can do hard turning on metal or wooden lathe provided the machine you’re using is strong enough for the forces created. If you use hard turning, it leaves spiral patterns on the workpiece surface, resulting in sealing problems.
5. Internal turning
You can use internal turning to enlarge the inner hole of the workpiece. If you make a hole through internal turning, it’ll be bigger and shallow with great structure and strength.
You can do this on either a wooden or metallic workpiece but using the right lathe. But ensure you check on the cutting force, angle, and chip evacuation.
To get the best results, go for the right tool nose radius, the groove, and the cutting-edge angle. Don’t forget about the tool treatment that determines the cutting force and the clamping method to determine the vibration magnitude.
6. Polygonal turning
Polygonal turning allows you to make a non-circular form without interfering with the raw material. It’s an alternative to milling, which makes flat planes. You need a unique tool to do this, like a cartridge with several cutting inserts.
You can mount the cartridge on an arbor having a keyway, then mount it on a CMZ axial tool holder. The toolholder should have a spindle or sub-spindle of around 12000rpm and internal cooling of between TL20/10400/06 and TL20/10400/08.
You can also use particular tool holders for polygon turning to mount cartridge without making an arbor.
7. Cylindrical turning
Cylindrical turning allows you to shape a metal workpiece internal or external surface longitudinally to the rotation axis. It helps you get the accurate size and the surface finish of your desire.
Before using a cylindrical turning tool, you’ve got to ensure they have perfect arrangements following specific rules.
When doing the cylindrical turning, you can combine it with facing and use one tool but ensure you observe the turning tool’s central position to be equal with the axis of rotation.
You can do cylindrical turning for long cylindrical parts, hollow cylindrical parts, and shouldered cylindrical parts.
8. Plain turning
Plain turning can help you remove extra material on surfaces of a cylindrical job. When plain turning, you have to supervise the lathe constantly.
It uses single-point cutting tools. You can use it to either shape steel, titanium, or aluminum. To do plain turning, you need to have high manual work skills.
9. Step turning
You can use this method to make several steps on different diameters. You can use it to make a staircase on a workpiece. To achieve this, you need to remove extra material from the workpiece but not in a uniform manner. The steps must have different measurements too.
10. Profile turning
Profile turning helps you cut various depth, speed, and feed. To achieve this, you need tools with big variations in stress and depth of cut because of the machining directions and change in diameter.
Ensure you use the correct insert shape that’s strong and affordable. Check on the entering angle, which largely depends on the workpiece. Also, go for the best tool holder with 93 degrees entering angle and a D-style insert.
If you want to make a profile in another direction, choose a holder with an entering angle between 107 and 117 degrees.
FAQ:
1. What is the difference between boring and turning?
Turning or boring perform similar processes with both the lathe and the milling machine using a static cutting tool to eliminate material from a gyrating workpiece.
The only difference between the two is that turning works externally on the workpiece while boring does it internally.
2. What is the difference between turning and facing?
Facing reduces the length of the workpiece you’re using, while turning changes the workpiece’s diameter. When turning, the tooltip maintains a constant temperature while facing the cutting speed determines the temperature, affecting the tooltip temperature.
More Woodturning Tips & Guides:
- Looking for a Pen making wood lathe? Check our guideline
- Looking for a standard bowl gouge for making bowls? Check our guideline
- Do you want to know the types of wood turning chisels? Read our article
Conclusion
Using either wood or metallic lathe will help you shape various workpieces with ease and within no time. To get the right shape, though, ensure you work with the right lathe. But know the type of shape you intend to make to enable you to go for the best tool to avoid damaging the workpiece.