Turning wood must be one of the most satisfying aspects of woodwork. To see a rough, unworked piece of wood slowly transforming before your eyes is a very uplifting experience. Apart from the chuck, which secures the wood as it spins, wooden lathes are generally straightforward pieces of equipment.
Not all woodworking lathe chucks are universal. Some chucks are individually adjusted, whereas those described as universal have three of four jaws interconnected via a scroll gear, which can be adjusted to a broader or narrower setting using a single tool.
The chuck is a very specialized clamp that holds a piece of wood that is being turned. The definition of the universal chuck has a different meaning for different people. Generally, it is a chuck that you can adjust with a single tool. It’s not always as simple as we explain in this article.
How Do You Know If A Wood Chuck Is Universal?
Before deciding if a wood lathe chuck is universal or not, we need to discuss the function of wood lathe chucks, the different types, and the different uses for each chuck.
In this discussion, we are only examining chucks used to turn wood.
Why Do You Need A Wood Lathe Chuck?
When turning the outside of a piece of wood, it is mounted between the headstock and tailstock spindles. As both sides are secured, it is easy to turn down the outside of the spinning wood.
When turning the inside of a wood blank, you need to work the inside, obstructed by the tailstock spindle.
When purchased new, most lathes include a faceplate. This adapter is screwed onto the piece of wood and attached to the headstock spindle.
Although this is a workable method, there are disadvantages.
- Attaching the wood to the faceplate is inefficient. Finding the center can be challenging if the wood blank is uneven.
- It is secured with screws, which must be long and strong enough to ensure the wood blank does not come loose. The length of the screws may restrict the area you can turn.
Wood Chucks have been designed to add a level of convenience to the woodworker’s life, in that the whole mounting process is sped up and made more accurate.
What Type Of Lathe Chuck Are Available?
There are two categories of a woodchuck, and these are further filtered down into the individual chuck designs.
The Three Man Categories Of Wood Lathe Chuck Are
The two types of wood lathe chuck are independent jaw chucks and universal (scroll) chucks.
Independently Jawed Chucks
These usually are four-jaw chucks, and each jaw is independently adjusted by its screw.
These chucks usually are cheaper than scroll chucks. They have the advantage that each jaw can be individually adjusted, which means that the turner does not always have to cut a tenon before fitting.
The disadvantage is that each jaw needs to be individually adjusted, which takes more time and requires more accuracy.
Universal Or Scroll Chucks
Universal jaws (Technical term – dogs) are connected by a scroll gear (scroll plate) to hold the wood blank in an automatically centered position.
Four-jaw combination self-centering chucks
Combination self-centering chucks offer several benefits between independently jawed chucks and universal chucks.
You can adjust each jaw individually, but once the correct measurements have been made, they loosen and tighten with the application of just one key. These chucks are excellent for repetitive work on square, rectangular, or irregular pieces that don’t require regular adjustments.
If you work on standard circular pieces of wood, they are an “overkill” solution.
Individual Chuck Designs
Within these two categories, there are several varying chuck designs.
Three Jaw Chuck Designs
Three jaw chucks are a weaker version of four jaw chucks. They have been developed from the metal lathe industry and are generally lower-cost options to 4 jaw chucks.
Overall, they are less flexible and can’t hold square pieces of wood. Although you can use them to turn wood, they are more suitable for metalwork.
Jacob Chucks
A Jacob chuck, often called a drill chuck, is similar to the chuck found on regular high-speed drills.
Jacobs chucks are great tools to quickly Mount Wood to sand them.
Universal Four Jaw Chuck Designs
Four jaw chucks are the best option for woodturning. With a universal (scroll), each of the four jaws moves symmetrically when Tommy bars, an Allan key, or a specialized tool is manipulated.
The four jaws scroll in and out to hold either square or round stock securely.
The cost of a four-jaw chuck is often related to the quality and durability of the part.
Any four-jaw chuck which costs less than US$100 should be evaluated very carefully before being purchased.
Things To Look For When Buying A Universal Lathe Chuck
To help you decide on the specifications of your first universal chuck, the following list some of the factors which you can consider.
The Diameter Of The Universal Chuck
The average diameter chuck is 100mm overall; generally, this is the optimum size for most non-commercial lathes.
Larger and smaller chucks are available; however, if you want a bigger one, remember size is not essential.
Irrespective of the size of the chuck, you will have to cut a parallel or dovetail tenon anyway; the wood blank can essentially be made to fit the chuck. It doesn’t make much difference after you get used to cutting the parallel or dovetail tenon.
A larger opening can be weaker than a smaller hole.
How The Universal Chuck Attaches To The Lathe
Chucks are sold with an interchangeable threaded insert or a direct thread on the chuck body itself.
Interchangeable threaded inserts mean that you can adapt the chuck between different lathes with varying lathe threads.
Direct threaded chucks have the threads cut into the chuck body itself. They can only be used on one lathe headstock center and cannot be used with different models. Some manufacturers make an adjustable insert that can fit on direct threaded chucks.
Don’t Buy The Cheapest Universal Chuck
The quality of chuck determines its life expectancy. As a rule of thumb, don’t buy three-jaw universal chucks (except Jacobs chucks which work well), which may be selling for a lower price than the equivalent four-jaw universal chuck.
Choose Between An Open Back Or Closed Back Universal Chuck
Closed-back chucks have a plate over the rear of the chuck, which stops sawdust from entering. The scroll gear is adjusted with a large Allen key.
As the name implies, open-backed chucks do not have covers over the rear; this exposes them to sawdust. The reality is that you can easily blow the sawdust off. These chucks use a sizeable key wrench with tapered teeth to adjust the scroll hear.
Both offer good service and durability, and the final choice will come down to your personal preference.
One benefit of a closed-back chuck is that you can use a conventional Allen key in its place if you lose the Allen key type wrench.
The Method Of Mounting Mount The Jaws To The Universal Chuck
There are two ways to mount the jaws onto the chuck – by screw or a quick-mount system found in chuck systems such as the “Easy chuck” or the “Infinity Chuck” from Tech Tools, which are often double the price of screw-type systems.
There Are Two Basic Styles Of Universal Chuck Jaws
The two methods of mounting the wood blank to the two different universal chucks are defined by the shape of the jawline.
The two types of mounts are
- Cut a dovetail tenon
- Cut a parallel tenon
Either works and if you use them properly (check the chuck instruction manual for the method), it will come down to what you prefer.
How Much Do Universal Chucks Cost?
The better the chuck, the longer it will last.
The cost of chucks ranges from $50.00 to $800. Don’t buy one costing less than $100.00. If you can’t find a decent, affordable chuck, consider purchasing a good, used chuck.
Conclusion
A chuck adjusted by one key which turns a scroll is considered a universal chuck. After you have identified that a chuck is universal, you must consider all the options that make it the right product.
Buying a universal lathe woodchuck will change how you use your lathe and help you produce turned pieces of wood of which you are proud.
References
https://askinglot.com/how-does-a-wood-lathe-chuck-work
