Holding your work.
One of the first difficulties you will come across whilst woodturning is how you are going to hold a piece of wood on the lathe whilst at the same time not degrading the piece by putting screw holes into it. There are a whole range of different ways that the wood can be held, some of which I will try to explain here, the first of these is what we woodturners refer to as “between centres”, this just means that the wood is normally held between the headstock and the tailstock. To do this a couple of items need to be present, a drive centre and a tailstock centre. There are numerous types of both of these on the market, they range from 2 prong drive centres to 4 prong drive centres and the more recent introduction of the steb drive centres. And for the tailstock a similar story is true, they range from a dead centre to a revolving centre with a tapered point and a steb centre with a revolving bearing, all of these are available on morse tapers and the most common of these are morse taper 1 and 2, your lathe is only going to require one size of taper, they very seldom mix the sizes on a single lathe unless you come across a very old lathe.
This is what’s referred to as “between centres”
Mainly for spindle work, where a square section of any length is used.
Top, a steb drive centre.
Bottom, a 4 prong drive centre.
Both of these are on number 2 morse tapers.
This has a single point revolving centre on a number 2 morse taper.
Left, 4 prong drive centre mounted in the headstock.
Right, steb centre mounted in the headstock.
The point in a steb centre is spring loaded which makes mounting the wood so much easier.
Left, the revolving centre mounted in the tailstock.
After cutting your selected wood to the size you require, the first job is to find the centre of the blank. To do this draw two lines from corner to corner as shown above, the intersecting point of the two lines is now your centre to work from. This needs to be done on both ends.
Using a bradawl or similar make a small indent where the two lines intersect, this helps with the setting up on the lathe. Place the wood onto the steb centre at the headstock end first using the point of the steb centre and the small indent you created (picture above right). The steb is spring loaded, but no pressure is to be applied just yet.
Holding the wood with your left hand, bring the tailstock up to hold the other end. Here I’m using a standard pointed revolving centre, locate the centre in the indent and lock off the tailstock to the bed of the lathe, now turn the handle on the tailstock pushing the wood onto the steb centre and embedding the revolving centre at this end.
Apply just enough pressure to hold the wood securely, but not over tightened. The steb centre will have been embedded in the headstock end giving the drive necessary to work the blank, whilst the revolving centre will give you the hold without the friction of a dead centre. Now lock off the quill on the tailstock.
If you are using a 4 prong drive centre the proceedure is slightly different. Mark both ends as before with a pencil, but on one end cut both lines to a depth of about 3mm with a saw and drill a small hole in the centre as shown left. The reason for this is that the 4 prong drive centre does not have the spring loaded centre point and the 4 prongs need to be located in the cuts to give you the necessary drive
Left, the 4 prong drive centre can be seen located into the cuts giving a very positive drive thrust. The tailstock end would be treated just the same as was done with the steb centre.
Left, the blank now mounted between centres, ready for the tool rest to be positioned and the turning to start.
These two are also revolving centres but of the steb variety, they could also be used instead of the point revolving centre, here you can see they are two different sizes, the bottom one being of a larger contact size is especially useful when working with laminated woods as it takes some of the pressure off a glue joint when that joint is in the middle of the blank.
Examples of screw chucks.
A, a fine threaded screw chuck.
B, a slightly larger screw chuck. Below, a disc of hardwood that can be used as a spacer and a softener.
C, a Vicmarc screw for the chuck.
The Vicmarc screw now mounted in the chuck, it’s very strong with what’s known as a buttressed thread making it very secure when being worked. The wood is screwed on untill it touches the face of the chuck jaws.
This is the middle screw chuck (B) mounted in the chuck, it has a parallel thread on a 10 gauge screw which can be removed and replaced, held in by a grub screw, useful if you need to use different lengths of screw.
This again is the middle screw chuck mounted in the chuck, this time it has the wooden spacer/ softener fitted over the screw, the spacer provides a wider landing area along with some protection to prepared surfaces from the green baize.
The last of the screw chucks mounted in the chuck, this one has a conventional replaceable wood screw, 8 gauge and the face of the chuck has been softened with green baize, a useful chuck for lots of small items.
How it works, here I have selected a small bowl blank from Native Beech, it’s 125mm in diameter and 70mm thick, using the Vicmarc screw in the chuck, I have drilled an 8mm hole 35mm deep in the centre of the blank to accommodate the screw.
The picture (left) shows the blank being mounted onto the screw, it needs to be screwed all the way on until it comes in contact with the face of the chuck jaws, it’s those jaws that spread the load making it possible to be worked.
Now the blank is firmly screwed on and fully in contact with the face of the chuck jaws. For most work on this screw chuck it would be ready to be worked but if you feel a little more support is required then bring up the tailstock prior to making your first cuts.
The Beech blank above is now ready to be worked, start by levelling the aspect facing you using a 3/8″ bowl gouge, then level out the base at the tailstock end, again using the same tool stopping just short of the point of the tailstock centre, then using a parting tool level out the chuck end of the blank, this is done by taking a few light cuts from the outside towards the centre stopping just short of the chuck jaws. The side nearest the chuck needs to be the top of the bowl so that means the shaping for the bottom of the bowl needs to start at the tailstock end, work from right to left on this or from small to large, quite a lot of the shaping can be done with the tailstock in place, however once the majority of the shaping has been done you will need to take the tailstock away to finish the shaping, it’s also at this stage that you will need to put the recess in the bottom for the dovetail jaws, when it’s turned round it will need to be held by the dovetail jaws, it’s at that stage the inside of the bowl can be worked removing the hole for the screw chuck in the process.
All screw chucks work in the same way, you need to drill a hole in your blank to suit your screw size then screw the wood tightly onto it, bearing in mind the capacity of the screw, the smaller the screw the smaller the piece of work needs to be.
There are lots of items that can be made using a screw chuck, such as the small bowl shown above, just remember this method can only be used on an item that has the mounting point removed as part of the design.
Faceplates and Faceplate Rings.
Faceplates and faceplate rings are probably the most used methods of holding the wood on the lathe, most new lathes will come with at least one faceplate as standard but very few supply the faceplate rings, these need to be purchased separately. The faceplates are used mainly on larger discs of wood for making bowls, attaching them to the top side of the wood by using 4 screws, allowing you to turn the outside and the foot of your bowl including the chuck recess, this means that the screw holes will be removed when the bowl is remounted on the dovetail jaws and the inside is worked.The faceplate rings work in exactly the same way as a normal faceplate, the only difference is that the chuck is used with a set of dovetail jaws to mount the wood, remounting any piece with a faceplate ring is much more accurate than trying to remount a faceplate once it’s been removed. I would recommend you purchase at least one faceplate ring in addition to any faceplate supplied with the lathe.
This is my Vicmarc faceplate, it’s cast steel for heavy duty work, 6″ (150 mm) in diameter with an M33 thread. These are available from Vicmarc in sizes from 4″ (100 mm) up to 10″ (250 mm) and with a variety of thread sizes to suit most lathes. When using faceplates or faceplate rings, use at least 4 screws of a suitable size, my preference is 1″X 8 gauge, (25 x 4 mm).
Two of my faceplate rings, both will fit onto the standard dovetail chuck jaws of 50 mm. The larger of the two will do the same job as the 6″ (150 mm) faceplate but it will also allow me to take it off the chuck for any reason and remount it without any loss of accuracy as indeed the small one will also do.
When making shallow items or items that you do not want to have screw holes in them, then this is the solution, the disc is 10″ x 1″ thick and to be used as a tea pot stand. I have cut a disc from any scrap wood and glued it to the work piece by means of hot melt glue, it’s the same size as that of the small faceplate ring. There will be more on the glue chuck method later on.
The same work piece with the small faceplate ring positioned onto the scrap disc ready to be screwed down. The scrap disc is approx 70 mm in diameter and about 30 mm thick allowing you to use 4 x 1″ (25 mm) screws. From this position you would turn the base of the item including the chuck recess, then removing both the faceplate ring and the scrap disc once it’s been turned round.
On this bowl blank I have put a larger faceplate ring on, it requires a set of dovetail jaws that will expand to 80 mm, the blank measures 125 mm in diameter by 70 mm thick in Ash, the larger ring gives a much better stability to work the outside. The entire outside shape including the chuck recess can be turned from this set up, once complete the work can be turned round, mounted on the dovetail jaws, the ring removed and the inside of the bowl worked removing the screw holes at the same time.
The 70mm faceplate ring mounted on the dovetail jaws on my Vicmarc lathe, I have omitted the wood for the purposes of clarity.
The 6″ or 150mm heavy duty faceplate mounted on the spindle of my Vicmarc lathe.
The next sequence of pictures shows how it’s prepared for and used.
I have selected a blank of Elm to be mounted on the faceplate, it’s 365mm in diameter and 50mm thick, you will see the centre is clearly marked, this was used to mark the diameter for cutting on the bandsaw, and will now be used to determine the position of the faceplate.
The first thing to do is mark a circle on the wood to match that of the faceplates diameter, use a compass for this and make it just slightly bigger than the faceplates diameter.
Now position the faceplate inside the circle marked on the wood, it may require a little judgement to get it as central as possible. Once this has been done, mark one of the screw holes with a pencil and drill a pilot hole for the first screw, reposition the faceplate and screw it down, once tight drill the remaining 3 holes and fix with 3 more screws, I used 1″ x 8 gauge screws.
Having tightened all the screws, it’s now time to put it onto the lathe, place the faceplate onto the shaft and screw it on until it’s tight.
The blank now ready for the turning to begin. You may observe that this blank has 2 small areas missing, top and bottom, this is because the blank has come from a cut that was very close to the outside of the tree and 2 areas of bark were left on, one I have removed the other is still there, this is not a problem as this will be the bottom of the bowl, these areas will disappear as the turning progresses. I took this into consideration while deciding on which side to put the faceplate.
Chucks and Jaws.
This is the area in woodturning where I have seen the biggest improvements happen over the last 40 plus years, the modern day 4 jaw chuck with interchangable jaws is a must for all would be woodturners. Paramount amongst these in my opinion are the Vicmarc chucks and their wide range of jaws. I’m not going to take you through all of their different chucks and jaws, but I will suggest a good starting chuck and a few sets of jaws that will make your experience with woodturning a whole lot easier and definately much more pleasurable. Why a 4 jaw chuck as opposed to a 3 jaw chuck I hear you ask? well the answers very simple, a 3 jaw chuck will only accept material that’s in the round, the 4 jaw chuck will accept round or square material, and that’s a huge plus in my opinion as most of the wood blanks come square.
This would be my choice of chuck, it’s a Vicmarc VM100 with a standard set of dovetail jaws, it’s about 4″ in diameter and the standard jaws would fit a recess of around 50mm, it comes with an M33 thread or with an M40 thread that would then accept an insert to make it fit any lathe. The jaws are interchangable and can be changed to any of the wide range of jaws available in the VM100 range,
These are 3 more sets of jaws I consider to be essential for use with this chuck.
A, a set of shark jaws.
B, a set of pin jaws.
C, a set of long nose jaws.
I will discuss in detail each of these jaws in turn.
A side view of the same 3 sets of jaws, but showing only one segment of each set of jaws.
Another very useful set of jaws that can be used with the VM100 chuck are these bowl jaws, they are available in 3 sizes, 285mm, 385mm and 485mm, the swing over the bed will determine which set to get, or if your lathe has a swivel head facility then any one of these will be appropriate.
The bowl jaws in use, these are used to hold the wood from the rim as opposed to the base, this is mainly done when the base of a bowl or plate is re-worked in order to remove any trace of the chuck recess as with this Elm bowl.
A set of pin jaws, these are used with a 25mm hole drilled into the wood to a depth of 20 – 25mm and the wood then placed over the pin and tightened by expanding the jaws, these are also available in a slightly bigger size of 35mm, making them very suitable for quite large wood blanks. Their main use is in the making of natural edged bowls.
The long nose jaws fitted on the chuck and on the lathe. These jaws are smaller in diameter than that of the standard dovetail jaws which makes them very useful when making smaller bowls or plates. They require a recess that’s only 35 to 40mm in diameter, the depth of the recess does not need to change and should remain at about 3 to 4 mm deep.
The bowl left shows the finished exterior, the shape the foot and the chuck recess. This bowl is only 200 mm in diameter by 60 mm thick and I did not want a large chucking recess so the long nose jaws were perfect for this bowl, I made the recess 37 mm in diameter by 3 mm deep and put a couple of decorative lines on the inside of the recess. The wood is Oak.
A close up of the same bowl showing the foot and the chuck recess a little clearer. Do remember the inside edge of the recess needs to be tapered to match that of the dovetail on the jaws.
The same bowl again, this time it’s seen after being mounted on the long nose jaws. At this stage the inside of the bowl was still to be worked.
A close up of the bowl as it was mounted on the long nose jaws, as you can see there are gaps between the jaws after it was tightened up, this would mean I could have cut the recess a little smaller to about 35mm instead of the 37mm I did cut it to. Do bear in mind the recess needs to be big enough to take the full width of the closed dovetail but will open up as it seats it’s self into the taper.
These are what’s known as shark jaws, a very heavy duty set of jaws. They can be used in either contraction or expansion mode, in contraction the minimum internal size of any spigot or round piece of wood needs to be no less than 42mm, in expansion mode they require a hole of no less than 50mm by 30mm deep, the ribbing on these jaws internally and externally make for a very strong hold once tightened up.
One of my more unconventional methods of holding something on the lathe is the glue chuck, it’s made up of a disc of scrap wood that’s held on the lathe by whatever means you feel appropriate, it could be held in the jaws of a chuck, or on a wood screw, or a small faceplate, or my preferred method is on a faceplate ring. The glue I use is hot melt glue, it comes in stick form and is fed into a glue gun which is heated to the point where it melts the glue, most of these glue guns have a trigger mechanism to advance the glue stick through the heated area of the gun, melting the glue as it goes through. The glue sticks I use are 12mm in diameter and 300mm long and used for paper, card or wood.
My glue gun, a fairly standard glue gun, takes 12mm glue sticks and is trigger fed. It takes about 5 minutes from when it’s plugged in until it’s ready for use, it has to heat the sticks to melting point first.
To use the hot melt glue method you will need to make up a wood chuck to glue onto. Here I have cut a disc of scrap wood about 100mm X 30mm and fixed a faceplate ring to it, this will be my base to glue the blanks to.
Using my standard 50mm jaws, I have mounted the base by means of the faceplate ring. Now the edge of my scrap disc can be turned to a true disc
After the edge has been trued up, it’s the face of the disc that’s now worked, firstly do a cut from the edge to the centre keeping it as flat as possible, then put a series of grooves in the face, this helps with the positioning of the blank and gives a better surface for the glue to work
This is the blank I am going to use, it’s Sweet Chestnut and measures 50 X 50 X 120mm. This is the size I would use for all of my weed pots, full instructions on how to make the weed pots can be found under Project 1 in this web site.
I have found that it’s better to put the glue on the blank rather than on the prepared disc, you need to work fairly quickly as the glue starts to set as it cools down. Use a liberal amount as shown here, this helps to keep it liquid for as long as is necessary.
Positioning the blank on the disc, use the grooves as a guide and press the glued end onto the disc, you will be able to adjust it for a short while so that it’s central, bring up the tailstock right away and lock off where it lands, do not try to move the blank at this stage. Allow to cool, 2-3 minutes before any turning can begin.
Another very good use of the glue chuck comes in the making of wooden Mushrooms, especially the type that have been off set a little, as shown left. Here I have cut the base end of the blank on a slight incline, say 5 degrees, then mounted it centrally on the disc with the hot melt glue throwing the other end way off centre as can be seen at the tailstock end, this makes for a very different look to the finished mushroom. For mushrooms, see Project 3 in this web site.
Left, a book that might be of some interest to you, it is as you can see all to do with how to hold things on the lathe. I can’t help noticing that the author of this excellent book has a very appropriate name, his name is FRED HOLDER.
I’m not sure if this book is currently still in print but I did find it available through Amazon and ebay.
There are of course more ways to hold the wood on the lathe, I have covered what I consider to be the most used along with a little deviation of my own that being the hot melt glue system.
A couple of examples of more advanced methods of holding work on the lathe would be , a vacuum system and the other is the Escoulen chuck or eccentric chuck, both of which I will cover in another page.