Introduction: How to Grip Your Woodwork
Once you’ve bought your lathe and some basic tools, the next consideration is how you are going to grip the work securely enough to allow it to be turned safely. In fact, holding the work is more than half the battle in woodturning, and with experience you’ll soon develop a range of different strategies to suit the item being made and your particular way of working. Alan Holtham talks us through how to grip your woodwork.
Step 1: Holding Spindles
Holding spindles is relatively easy, as these are just held between centres which fit into the Morse tapers of the main spindle and tailstock, photo 1.
Step 2: Drive Centres
The drive centres for the headstock are available in a variety of sizes and patterns, depending on the diameter of work you are turning. One with four prongs and a diameter of about 1in will cover virtually all your needs, photo 2.
Step 3: Two-pronged Versions?
For smaller section material, a 5⁄8 or 1⁄2in diameter centre might be needed, but don’t bother buying one of these unless you actually need it. There are some two-pronged versions available, photo 3, but these should be used with care as you can split the work if you’re too heavyhanded with them.
Step 4: The Tailstock End
At the tailstock end, the work is supported by another centre, which ideally should be of the revolving type, photo 4.
Step 5: Don't Burn the Wood
Although they’re bulkier, they spin with the work so you can apply enough pressure to get it secure without worrying about overheating. If you use the cheaper fixed or ‘dead’ type of centre, there’s a real chance of burning the work, photo 5, particularly if as a nervous beginner you tend to overtighten things.
Step 6: Cheaper Dead Centres?
If your lathe comes with a dead centre as standard, it’s well worth buying a revolving version. They don’t cost a fortune, but do buy a reasonable quality one; the cheaper versions are often poorly made, with inadequate bearings that can introduce vibration problems, photo 6.
That’s all you need for working between centres, but there are many situations where you can’t hold your work like this – for example, when you need free access to one end of the workpiece – but in this case there is a much wider range of options available for mounting the work securely.
Step 7: Faceplate
The conventional holding device is a faceplate, photo 7, and in fact a lot of flat work is still called faceplate turning even if it’s actually held by some other means. I was taught to turn in the days where a lathe had just a set of centres and a faceplate. If you couldn’t hold the work by either of these methods, you then had to make some form of temporary wooden friction chuck as part of each individual job.
Fortunately, things have moved on and there’s now a whole variety of very versatile chucks that provide instant solutions for virtually every holding situation. I’ll cover these in detail in the next issue.
Advanced chucking systems are now a necessity rather than a luxury, and most serious turners will have at least one. However, there are still situations where a simple faceplate, or its close derivative the screwchuck, provides the easiest and most efficient method of holding work. In fact, a faceplate may be the only way of getting the initial hold whilst you turn some sort of spigot or recess for subsequent gripping with a chuck.
Step 8: Size of Faceplate
Faceplates come in a variety of sizes, but you don’t need a lot. As usual, it depends on what sort of work you do, but for general use a 4in version is all that you’ll need. It’s worth thinking about adding a 6in one if you want to do a lot of big bowl work, and perhaps a smaller one if your ambitions are more modest, photo 8.
Step 9: Steel Faceplates
Although a faceplate is apparently very simple, it’s important to buy a good-quality one. I would prefer a machined steel faceplate with a short boss, as this will run true and is less likely to distort than the aluminium versions. As well as distorting as you screw them onto uneven workpieces, the aluminium ones also tend to chew up round the fixing holes after only a little use. This doesn’t happen with steel, photo 9.
Step 10: Strength Matters
Many of the cheaper lathes now seem to come with a standard 6in cast-iron faceplate, which as well as being thin and not particularly accurate, also has a long central boss which introduces another potential source of distortion and vibration, photo 10. It really is worth investing in a better quality one.
Step 11: Screw Holes
Remember that if you have to screw the faceplate on to a very uneven surface, strength is very important, though you may still have to pack it out in some situations if you need to adjust the orientation of the blank. Plenty of screw holes is an advantage here; try to put a screw through each packing wedge as well to stop them flying out, photo 11.
Step 12: Faceplate Problems
When you start hanging big and heavy pieces onto the spindle, it’s vital that the faceplate is screwed right up tight before you start the lathe. It’s so easy to leave it a fraction of a turn off tight; then as soon as you start up, the inertia of the blank causes it to screw on with a juddering thump. This makes it extremely difficult to remove later, photo 12.
Step 13: Washer
If jammed faceplates are something you regularly struggle with, and you’re sure they are up tight before you start each time, then try fitting a washer of some sort between the plate and the headstock spindle. Any material will do for this as long as it is soft, photo 13. Cork, fibre, leather or cardboard are all fine and a washer always eliminates the problem.
Do also remember to clean out the threads of the headstock spindle occasionally, as this can stop the faceplate screwing right up. Take great care not to cross-thread it, particularly when loading very heavy workpieces, as the spindle is difficult and expensive to replace.
Step 14: Screwchucks
An even more useful device for holding workpieces is the screwchuck, and I would rate this as one of the most useful lathe accessories. Again available in various shapes and sizes, this is essentially just a small faceplate with a fixed central screw. Common sizes are 11⁄2 and 21⁄2in in diameter, photo 14.
A standard screwchuck should take normal woodscrews so you can replace them as they wear. The only snag with this is that they are usually No 14s, which can be very difficult to find unless you know an old-fashioned ironmongers. If you try and use thinner gauge screws, they never seem to lock in securely. Beware of screwchucks with permanently fixed screws.
Step 15: Length of Screw
For maximum versatility, you need to be able to vary the amount the screw projects from the chuck. While you can do this to some extent by changing the length of the screw, photo 15.
Step 16: Screw Seating Position
Better chucks will allow you to adjust the seating position so you can control the length more precisely, photo 16.
If you’re buying a screwchuck, try to find one where the screw is held in by a threaded boss and the head is retained by a spline in the screw slot, photo 17. This sounds very complicated, but all it means is that the screw cannot then turn as you twist it in or out of the work. Screwchucks that rely on holding the screw just with an Allen key into the side are rarely successful, and become very frustrating to use – either the screw keeps turning, or the work becomes loose as you are working.
Step 18: 2.5in Screwchuck
If you’re on a limited budget and it’s a toss up between buying a faceplate or a screwchuck, then buy just a 21⁄2in screwchuck which has additional screw holes. Then you can remove the centre screw and use this as a small faceplate as well, photo 18.
Step 19: Pilot Hole
Many newcomers to turning really struggle to get a screwchuck to hold securely, and give up on them as a result. This is a shame, because it’s one of the simplest and most useful of all holding devices and is foolproof as long as you follow a few basic rules.
Firstly, it’s important that you make the pilot hole the correct size and drill it to the right depth, photo 19. Forcing the screwchuck in without a pilot hole will not give a stronger grip but will actually work in reverse, as the thread crumbles and strips as it struggles to form.
Step 20: Screwing in the Chuck
Secondly, be aware that the action of screwing in the chuck will throw up a burr around the hole, photo 20.
Step 21: Gap
This will stop the timber seating firmly, leaving a gap between the screwchuck and the end of the timber, photo 21. A tiny amount of play at the chuck end becomes greatly magnified at the other unsupported end, and any attempt to turn with it like this results in the timber being torn off the screw, which is when most people give up!
Step 22: Space for the Burr
There are several ways of overcoming this and getting a secure seating. If the chuck has a central fixing boss, try dropping this in lower than the rest of the chuck face so there’s somewhere for the burr to go when you tighten up, photo 22.
Step 23: Turn the End
For longer pieces, firstly turn them between centres and trim up the end square – or preferably make it slightly concave, photo 23, so that the rim of the chuck fits up tight and there is absolutely no chance of any wobble, photo 24.
Step 24: A Single Screw
If you take this much care, it should be possible to hold a piece of sound 3 x 3in timber about 6in long with just a single screw into the end grain, photo 25.
Step 25: Additional Screw Holes
If the timber is soft or much longer, use the additional screw holes as well, photo 26.
Step 26: Cross Dowel
Sometimes, no matter how careful you are, the screw will not hold in end grain. In these situations, try drilling a hole through the blank and putting in a dowel at right angles to the grain. Once the screw gets hold of this, photo 27, there’s no way it will come off!
Step 27: Cross-Gain Work
If you’re attaching to cross-grain work such as a bowl, then a single screwchuck will hold surprisingly large pieces providing it seats flat, photo 28.
Step 28: Summing Up
The one disadvantage of both screwchucks and faceplates is that they are invasive, leaving you with screw holes as a permanent reminder of the holding method. In the case of the screwchuck you can part off clear of the screw, but this is rather wasteful, particularly if you are working with expensive timbers, photo 29.
Nevertheless, both faceplates and screwchucks are essential lathe accessories and you’ll need to use both of them at some stage, no matter what type of woodturning you are doing.