When first starting out, it can be a bit confusing determining how to attach wood to a lathe. What makes one method better than another? And worse, why does one person do it this way while another person does it differently?
I think once you thoroughly understand these three approaches for attaching wood to the lathe, you’ll have a better grasp on why, how, and when to incorporate them into your bowl turning.
Once a bowl blank is ready for the lathe it must be attached properly to begin turning. There are three straightforward, easy, safe and secure ways to attach wood to a lathe that we’ll go over in this post. Each method to attach wood has its strengths and advantages and also some drawbacks.
Two Times To Attach Wood
There are two main attachment times a bowl will go through during production. First, the bowl blank must be attached to the lathe in a manner that allows enough access to the base to form a tenon and then shape the outside of the bowl.
Secondly, the bowl needs to be reversed, following the creation of the tenon and outside shape. With the tenon made, the bowl is rotated and attached to the lathe with a four jaw chuck for the continued creation of the bowl’s interior.
The tenon is a nob like cylindrical extension on the bottom of the bowl used as a holding point for the four-jaw chuck. If you’d like to learn all about creating the perfect tenon, read this article.
A mortise can also be created. In this example I’ll be showing a tenon. Read this article all about creating a mortise bowl connection. And if you’re not sure whether to use a tenon or mortise, this article might help you decide.
As you recall in the article about preparing a wood bowl blank, the shape of a bowl blank can range from a simple cut off the limb to a large balanced and true cylindrical blank of timber. The shape and size of the wood blank will be a factor in how a bowl blank is initially attached to the lathe.
All of the different approaches explained here will be used to create a tenon or foot to later reverse the bowl blank and attach it to a four-jaw chuck. If you’d like to turn a bowl without a four-jaw chuck, check out this article.
The spur chuck is an inexpensive and quick way to attach wood to a lathe. A spur chuck is a “drive-center,” which means it does not spin freely on bearings.
It is driven by the headstock and has a solid Morse taper shaft that fits inside the hollow center of the headstock spindle.
The wood bowl blank is then centered between the spur chuck and a “live center,” with bearings, which do spin, attached to the tailstock.
One of the significant advantages of using a spur chuck is that the wood bowl blank can easily be loosened and repositioned on both the headstock and tailstock side independent of each other, and at any point during the turning process.
Being able to readjust is beneficial, especially when turning a rough blank with an undetermined bottom shape.
Many times while shaping the bottom curve of a bowl it will be discovered that one side requires much more turning away that the opposing side.
Instead of whittling the bowl blank down by removing excess material on one side to match the other light side, the blank can be visually re-centered on the tailstock.
Readjusting the bowl has the effect of averaging the heavy side with the light side leaving more material to shape and create the final bottom bowl shape.
Another advantage of the spur chuck is speed.
When you attach a wood bowl blank with a spur chuck, the bowl blank can be prepared quickly and efficiently changed by simply loosening the tailstock and removing the turned wood piece and introducing a new bowl blank. This is a great option if speed and production are important.
Spur Hidden Safety
While it is not designed to spin freely like a live center, the spur chuck will slip and rotate if excessive resistance occurs while turning.
Slipping can be a positive and negative feature of the spur chuck. If the bowl blank is problematic and presents catches, those catches are minimal with a spur chuck.
Instead of having a sudden potentially violent catch, the spur chuck will merely begin to slip and reduce the lathe’s drive speed.
The turning wood may come to a complete stop even though the motor and headstock spindle is still turning. If the spur chuck slipping is not desired, tightening the tailstock will reduce the potential for slippage.
Keep in mind, the connection of the spur chuck in the Morse taper is pure friction and not a hard fast mechanical bond like the other techniques we will cover.
The spur chuck may not necessarily be a good solution to attach wood that is large and heavy to a lathe. With the added torque and momentum of larger bowl blanks, it’s more likely that the spur chuck will rip out the wood fibers at the point of contact, which will reduce the holding strength of the chuck.
Also, the added force of larger bowl blanks makes it easier for a blank to come off the lathe while turning.
Spur Chuck and Tenon
Turning a tenon while using a spur chuck can be a bit of a challenge as the tailstock will be in the way.
With a little practice, working around the tailstock is not difficult but requires a bit more time than having the end of the bowl blank free of the tailstock.
Working around the tailstock also adds the extra step of removing the tailstock stub before the turned tenon can be rotated around and used to hold the bowl blank in a four-jaw chuck.
An efficient option for mounting wood to the lathe and turning quickly and securely with a tailstock-free, exposed tenon work area is the screw chuck.
The screw chuck, as the name implies, is a screw that is used to attach wood to a lathe at one solo point.
The center of the blank needs to be first located and a hole drilled to accept the screw chuck.
The size of the hole is essential. A drilled hole that is too small will make for a difficult time attaching and removing the blank to the lathe.
While on the other hand, a gap too large will allow the screw chuck to slip and strip out the hole, making the bowl blank spin against the headstock and not turn.
Some manufacturers may recommend the size of the hole to drill.
To find the right size drill bit, place a drill bit behind the screw chuck and look for the protruding threads. The drill size should be similar to the screw chuck shaft without the threads.
I’ve found that even with the correct size drill, green wood will severely grip the screw chuck and can be difficult to remove.
I typically remove the screw chuck and position its square head in a vise for leveraging the bowl blank until it loosens.
Accessory or Dedicated
Screw chucks come in a couple of different forms, fixed and accessory.
I use the accessory screw chuck that came with my four-jaw chuck. This accessory screw chuck looks basically like a giant bolt with wood screw threads.
At the base is a grooved area that aligns with the interior of the four-jaw chuck and receives the screw chuck insert as the four-jaw chuck is tightened down.
In this configuration, the four-jaw chuck jaws are the outer base that the bowl blank needs to be drawn down to meet.
It is essential to not only tighten the bowl blank in the screw chuck, but also to be sure that the surrounding area of the bowl blank seats securely on top of the four-jaw chuck jaws.
Dedicated screw chucks are available that include a fixed screw chuck with a surrounding support base.
Just as with the four-jaw chuck screw attachment, to attach wood to a lathe using the dedicated screw chuck, be sure to seat the blank all the way down to the base for a secure attachment.
In either configuration, if the blank does not seat at the base of the screw chuck, it can wobble or work loose and potentially go flying.
Flying wood is not something we desire in woodturning.
Once attached securely, a screw chuck makes an excellent attachment option for bowl blanks.
While the tailstock should be used whenever possible, it may be omitted if the blank is turning balanced without any troubles.
With the tailstock out of the way, forming the tenon of the bowl and shaping the outside of the bowl is a piece of cake.
Another great advantage to using the screw chuck is not needing to change the chuck on the headstock.
This technique doesn’t work for a dedicated screw chuck, as it needs to come off the headstock before attaching to a four-jaw chuck.
However, with an accessory screw chuck, the jaws just need to be opened, which releases the screw and then the bowl blank with a new tenon can be flipped over and placed in the four-jaw chuck ready to continue turning the interior.
One downside with the screw chuck is the fact that it’s not easy to re-center once the first hole is made.
If a slight adjustment is needed and a new hole needs to be drilled near the first hole, the resulting cavity may not support the screw chuck.
In this instance, small shims of wood can be added to an oversized hole in an attempt to make a suitable area for the screw chuck to grip.
Also, because the screw chuck is inserted in the wood blank, it is establishing a limited fixed axis which the blank must rotate within.
This fixed attachment makes its difficult to reposition the tailstock end of the blank after the turning process has begun.
Because of this, it’s important to take your time and determine the center of the bowl blank in advance.
If the depth of the screw chuck presents an issue for a small or shallow bowl, use a spacer.
A small square or multiple squares of thin plywood can be drilled and threaded over the screw creating a spacer. The spacers shorten the overall length of the screw making it protrude less in the bowl blank.
A good rule of thumb for a secure threaded grip is seven threads. When you attach wood to a lathe, try to have at least seven threads visible for a good hold.
The screw chuck is a great solution for production and ideal for small to medium bowl blank stock.
Large bowl blanks, like the spur chuck, run the risk of creating too much force on the screw chuck and can strip the wood out of the screw chuck connection.
The faceplate is the Mack daddy of bowl blank secure attachments to the lathe.
When it comes to working with large or abnormal wood bowl blanks, the faceplate is the way to go for a secure, dependable connection.
While the faceplate is a great go-to connect, there are some things you never want to do with a faceplate.
Faceplates come in various sizes. Because of this, larger faceplates can be used to attach larger blanks safely.
In general, larger faceplates are needed to attach wood to a lathe for larger, more massive wood bowl blanks, especially heavy wet green wood blanks.
Also, the tailstock should be used when necessary to add additional support, but is not always needed.
Because multiple screws are used to secure the faceplate to the bowl blank, there is little risk of the faceplate becoming detached from the wood blank.
It is essential to use good quality, appropriately sized wood screws or sheet metal screws and not drywall screws.
Drywall screws are made cheaply and not designed to hold much weight, and can snap under pressure. Good quality wood screws, preferably with a square drive tip, work best.
Sizing faceplate screws
It’s relevant to size the screws correctly. When I started out, my mentor insisted that the screws must be a number ten (#10) size, which indicates the thickness of the screw shaft.
However, when I went to put these screws in a new faceplate I purchased, they didn’t fit the screw holes. Instead, I used number eight (#8) sized screws, and they fit fine.
Use the most substantial screw width possible to fit your faceplate screw holes leaving no gap or play in the fit.
The length of the screws is essential as well. How long should they be? Well, long enough, of course. Seriously, however, this will need to be determined by a couple of factors.
The thickness of the faceplate should be removed from the equation. It is the screw depth into the wood that is critical.
One way to determine if a screw length is long enough is to place it into one of the screw holes on the faceplate and count lower exposed threads.
If seven threads can be counted, that will protrude into the wood; this is believed to be ideal. If fewer threads are counted, a longer screw is needed.
If more threads are counted, the screw may be needlessly too long and possibly run the risk of interfering in the final bowl walls.
Unlike the limited point connections of the spur and screw chuck, the faceplate covers a larger surface area of the blank making a stable foundation.
The give and take of this superior security is the adjustability once the turning process begins.
The location of the faceplate on the headstock side can be adjusted by removing all screws and repositioning the faceplate. This can be done to better center the bowl or reposition to take advantage of a slightly better angle.
Another slight drawback of the faceplate is its need to be affixed to a flat, smooth surface.
When turning a relatively rough bowl blank, it is necessary to smooth a flat surface to accommodate the faceplate. A flat surface can be accomplished in a couple of ways.
If a smaller faceplate is in order, a Forstner drill bit can be used to cut a flat circular location for the faceplate.
Be careful using a Forstner bit with small wood bowl blanks as the bit can grab the blank and take it for a spin. A large wood clamp or vise works well to hold the blank in these instances.
Use caution when clearing a flat faceplate area with a tool like this, because it can quickly catch and pull away from your grip. I’ve found nibbling away material slowly instead of trying to remove large chunks at a time works best.
Either way, as the flat area is created, it’s important to keep in mind that the faceplate is establishing the shape of the top and bottom of the bowl.
The flat bottom area of the wood bowl blank will be parallel to the faceplate. This factor needs to be taken into account when determining the prepared area that will receive the faceplate.
I typically mount the faceplate on my bench and will periodically bend down to confirm the location and angle of the faceplate in relationship to the flat bottom, especially when cutting the free-formed angle grinder area.
While seemingly a minor issue, it is essential to make sure the faceplate, with the attached wood bowl blank, seats all the way down and securely to the headstock spindle column.
If for some reason the faceplate doesn’t seat to the headstock spindle, a small plastic washer(s) can be used as shims to remove any gaps and create a reliable connection.
Any gap will cause vibration and result in a less direct smooth drive from the headstock at best, and the possibility of flying wood, at worst. Again, still not a desirable attribute.
The faceplate does require more time to prepare and attach than the spur or screw chuck, but the exchange for the added time is a secure connection that will hold the larger bowl blank stocks, all while leaving the tailstock area exposed for easy tenon creation and bowl shaping.
Whichever way you desire to attach your wood bowl blank to the lathe initially is ultimately up to you. Hopefully one or more of the techniques discussed here will fit the bill for you.
And I also hope you can see all the ins and outs of what makes each process right, or possibly wrong, depending on the specific bowl you decide to create.
What way(s) do you typically attach wood to a lathe? Leave me a comment below and let me know.
For details of the equipment mentioned in this article see my Recommended Equipment Guide.
Check out these additional related posts:
• 5 WORST TENON SHAPE WOOD BOWL (FOOT, SPIGOT, ATTACH)
• SAFE WOOD LATHE SPEED (CALCULATE, DETERMINE, ADJUST RPM)
• WOOD LATHE FACEPLATE – NEVER DO THIS – 8 THINGS