Click subject below for report

HANDLES & FEET with Graham Turner
OFF-CENTRE TURNING with Paul Reeves
PLYWOOD with Ed Walker
PODLETS  with  John Bolt
TEXTURING with
Paul Reeves
THREE LEGGED STOOL with
Paul Reeves

Click subject above for report


 

Paul Reeves
Demonstration of Off-Centre Turning
Thu, 20th February 2020 at MWCC Club Night

 

 

Eccentric turning can produce elegant and aesthetically pleasing pieces, for example :-
    Polygon Shaped Spindles
    Twisted Shaped Spindles
    Oval Tool Handles
    Cabriole Leg


 

Rounded Square Spindle

Both ends of the work piece were marked out with a centre-point and straight lines joining the centres (not the corners) of opposite sides.
Then a circle is drawn such that where it crosses the straight lines, these become the contact points for the drive & tail centres.
Care must be taken to ensure they are not too close to the edge of the finished piece or else the centres will not have enough grip to support.
With a compass centred on these four new points, draw arcs of the same radius to guide where the final edges will end up.
(The greater the radius, the more pronounced the angles at the corners will be)
Finally, number the four arc centres of one end (1 - 4) clockwise and once you've identified the corresponding number 1 on the opposite end, number these arc centres anticlockwise!
It will save quite a muddle later on.

Ensure the lathe speed is set low and any tool rest is well out of the way before mounting the work piece.
Using
● a Spring Steb DRIVE Centre &
● a Spring Steb or Revolving Ring TAIL Centre,
mount the work piece onto the lathe with drive & tail points on the arc centres marked 1.

The work will be offset so check that it clears the tool rest when the piece is rotated by hand.
With it out of balance you need to carefully adjust the lathe speed up until just before vibration starts to intensify.
Remember to stop the lathe if you need to readjust the tool rest.
Smoothly take off the one side with a roughing gouge.
(It's important not to push the gouge into the piece; just along the piece with the handle down to keep the cut gentle)
Check for a level surface as you turn away down to near the final edge marks drawn on the ends.
Sand using abrasives on a block just gently kissing as the lathe slowly turns.
Finish off each grit along the grain with the lathe stopped.

Repeat with centres marked 2, 3 and 4.
You might need to re-mount some of the centres to trim faces straight, even & level.

 

 

Twisted Spindle

The ends were marked out as above with the sole exception that once one end is marked 1 to 4, the corresponding number 1 on the other end must be one hole further round.
Once again, one end must be marked 1 - 4 clockwise while the other end marked anticlockwise.

Thereafter, work as above to smoothly turn off each side.
With eccentric turning, speed is your friend because the untouched section moves pass the gouge tip quicker so there is less tendency for the gouge to 'fall inwards' before the touched side comes around again.
A shadow will appear at the top of the piece; you should work to get that shadow parallel to the lathe beam.

Sanding with the lathe stopped may be more effective with applying the grits along the grain.
You might need to re-mount some of the centres to trim faces evenly.

 

 

Oval Handle

The reduced curves of the flatter faces will need a larger radius than the radius used from the centre of the work piece.
This may cause the offset centres to be near or even outside the finished cut.
Consequently, both ends of the work piece must be left uncut with enough length to ensure there is sufficient strength to support the drive & tail centres.
Remember to allow for this when selecting work piece length.

Marking up in this case benefits from drawing straight lines from the diagonals (to find the overall centre); draw a circle (which will become the widest dimension).
Then mark 2 arc centres equidistant from the work piece centre such that the drive & tail centres will have enough support up into the corner of the piece.
Draw in the arcs within the previous circle (to guide where the final edges will end up).
Take care that your centre marks on the other end correspond to the same diagonal!

The piece was mounted between centres and a parting tool used to delineate the ends of the finished handle to the depth of the widest dimension.
With a roughing gouge, a cylinder was formed to include any shaping required (eg curves for a handgrip) using the parting tool depth marks as a guide to the minimum size to turn away.
The cylinder was sanded through the grits.
The parting tool was then used again to reduce the spigot end-delineations to the depth of the guide arc on the end of the piece.

It was now mounted using the offset centres.
The same principles of tool rest positioning, lathe speed and smooth tool use were applied as highlighted above.
The newly reduced sized spigots showing up in the shadow of the turning piece now acted as a guide to how much to turn away each face.
The piece was sanded using abrasives on a block just gently kissing as the lathe slowly turned;
each grit finished off along the grain with the lathe stopped.
Then repeated using the other offset centres.
Be prepared to re-mount to one/both of the offset centres to get the faces even.

 

 

Cabriole Leg


First, we need to think of what happens when we offset in opposite directions from the overall centre.
Imagine a block of wood revolving and the shadow resulting will resemble the drawings here.
In figure 1, the amount of opposite offset at either end is the same;
In figure 2, there is a larger offset at the bottom.
The red line defines where there is no shadow and the piece appears stationary.
For want of a better name of something on a leg, let's call this the 'knee'.
You can see that the greater the difference in offsets at each end, the 'knee' moves closer towards the smaller offset end.
When turned away from the knee downwards, this will produce an elegant shape for a cabriole leg.

Whether the cabriole leg is for a seat or table top, its helpful to leave the top few inches as a square to aid attachment.
Feet are traditionally set on the diagonal so they face part forward and part outwards & look more stable.
Marking up the ends involves drawing in the diagonals to find the overall centre.
A very small offset should be marked on the top but on the bottom end, mark a larger offset on the same diagonal but the opposite side of the overall centre.
Remember to make a note of these offset distances for making matching legs.

Mounted between overall centres, Paul used a skew to cut a 'V' about 2" from the planned top end and deep enough to mark all four edges.
A roughing gouge turned away a cylinder from the 'V' cut down to the bottom end.
A bead was formed with a skew, spindle gouge or beading tool to tidy the V under the top square.
The planned bottom end was marked out for :-
● where the leg would touch the floor,
● widest part of the bead that the foot would stand on,
● widest part of the foot.

The piece was mounted between offset centres.
Working from the 'knee' towards the bottom, Paul turned away the shadow as far down as the widest foot pencil mark.
The piece was reverted back to centrally mounted to form the foot and the floor bead immediately below it.
The foot area and the knee areas were sanded as described previously.
Then while mounted between the offset centres, the knee to foot areas were sanded.

 

(photos by Mark Codling)             <to top>


John Bolt
Demonstration of Podlet turning
Thu, 19th December 2019 at MWCC Club Nigh
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Podlets are a name generally given to small thin wooden flower-like structures.
 

The choicest wood to select is wet/green, is of reasonable length to enable a degree of bend of the stalk; most with light or dark colours work well .  Natural edges look fine but it would not be a problem if all/some is missing (as explained below).
Another consideration is that the base be heavy enough to stably support the finished piece.


 

Bear in mind :-
● The piece will start off being supported between centres and that both ends will need to be squared off.
● The roundest end is better for the petal & supported in the tailstock; the drive end will eventually be trimmed as per your chuck spigot for supporting while hollowing out the petal and turning the stalk.
● Ideally, for strength reasons, you want to avoid the pith anywhere inside the finished stalk. Choosing a piece with an off-centred pith (eg horizontal branch with a large area of reaction wood above) would be ideal but otherwise, purposely plan to offset the centres such that the pith lies about 10mm from the stalk and so will end up being cut away.
● The tailstock will be removed for hollowing the petal but needs to support the piece when turning the stalk;
so a ring or cone live revolving centre would be the best to use.

While in between centres, start off at a slow turning speed as the piece will probably be out of balance.
Keeping the bark on the top end of the petal, even off the rest of the piece, which will gradually allow you to up the speed.
Start a shallow hollowing of the petal & form a spigot for your chuck at the drive end.
Mount on your chuck & continue hollowing with a smaller gouge (to avoid excessive vibration without the support of the tailstock) to a depth of at least an inch.

Once the inside is completed, finish with abrasives before continuing with the stalk & base.
Wet/Green wood tends to become fluffy and clogs the abrasive - problem reduced with wet sanding (i.e. dip abrasive into water)

Tailstock now returned into position but with some matting material to protect the contact area within the petal.
Trim back the bark towards the lip of the petal; if one side of the lip ends up too thick (perhaps due to avoiding the pith), an option is to reduce the protruding edge back into the round and then decorate the edge with a pyrographic tip.

Working towards the headstock about an inch at a time, turn out the stalk and sand finish as you work along while the strength of the piece is supported from the drive end.  John used a homemade Velcro-ed piece of plywood with various grits in order to even out the stalk as he progressed, making sure (where the stalk was particularly thin) to support the opposite side with his fingers.

Plan ahead where the piece will be parted off and thus where the start of the base should be.
The piece will look better with the base being a smaller diameter than the petal.
Reduce the base to desired diameter and shape to blend the curves.

Wet wood will naturally dry out and distort the piece.
For a more controlled process, one can microwave the piece with a heavy microwave-safe mug/bowl resting on the stalk.
After the one time he tried this method & the lady in the house expressed concerns of smells from the kitchen, John now uses steam from a kettle on a gas ring applied for about 4 or 5 minutes via a hose with a split in one end.

There is a helpful video on line <HERE>

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Paul Reeves
Demonstration of Texturing
Thu, 21st November 2019 at MWCC Club Night

 


When Paul asked his audience what they regarded as texturing, a few voiced it meant spoiling a lovely flat surface!
Paul had in mind something like, "Enhance a surface with interest or appeal." 
Not only visually but (perhaps more importantly) in a tactile way.

Putting on Texture improves a plain grain wood with contrast.  For example, applying a band of indentations about an inch below the outside rim of a bowl (where one's hands will invariably grip the piece) adds to the enjoyment.

There are four ways of applying texture :
● Both held tool and piece stationary;
● With the piece turning and a simple tool on the tool rest;
● Using a rotary tool with the piece held still;
● With the piece turning and using a rotary tool.

 

It is not necessary to have lots of texturing tools.
Simple Tools include :
    Ball Pein Hammer
    Straight Metal Bar with a domed head (Tip: avoid any with sharp edges)
    Hole Punch (Tip: smaller punches make colour tints look better)
    40 Grit Abrasive! (Tip: but keep it moving)
More Sophisticated Hand Tools :
    Thread Chaser
    Chatter Tool
    Coarse Hand Knurl
    Sorby Texturing & Spiralling Tools
    Henry Taylor Decorating Elf
Power Tools include :
    Angle Grinder (eg Proxxon)
    Electric Drill (eg Dremel)
    Power Carver

Techniques :
   
With the percussive tools, indent edges should meet while flat areas between indents be kept as small as possible. It is hard to be random but for the best effect, all indents should be kept of similar size and the same should apply to the spaces between. To keep depressions even, side grain areas will require slightly softer hits while end grain areas will require slightly heavier.  Hole Punches & Metal Bars tend to need harder hits, particularly with harder woods.
    When applying a band of texture, it is helpful to define borders for the band with grooves.  This is achieved with a round skew, a parting tool or even the point of a gouge; all placed so as to mask any marks outside the originally intended border line.  Any wayward indents remaining outside might be recovered with judicial use of woodturners spittle!

    A change of the lathe speed will result in different effects. With powered tools, the higher the lathe speed, the less regular the texturing while with the piece turning slowly or stationary, the cleaner the effect.  The opposite applies with the speed of the cutting tool - the faster the speed of the drill, normally the neater the finish.

A common decorative texture is Fluting.
These are best created using powered tools with accessories such as Ball Cutter, Chain Cutter, Flat Disc or Power Carver.
If applied with the lathe turning - present the tool in line to the rotation of the piece.
If applied with the lathe off - move the tool in the direction against the cutter's rotation.
The Power Carver tends to produce the smoothest fluting.

Once your texturing has been applied, you will probably need to tidy up the edges and clear away the 'hairy' bits.
Whether using a bristle brush by hand or a rotary tool with a brush attachment, move the brush in the same direction as the line of pattern.
A Blow Torch can be used to burn off hairy bits but should only be used if leaving as burnt decoration or if colouring with something which will cover up the inevitable scorch marks.

(photos by Mark Codling)             <to top>


 

August 2019 - Demo 3
Working Plywood with Ed Walker



It was surprising to learn that the Egyptians used plywood some 3500 years ago; the Royal Navy used several laminated layers of hand-sawn veneers at the end of the 18th Century; and in 1847 Sweden, Immanuel Nobel (father of Alfred) realised that several layers of wood bonded together was stronger than a single thick layer and subsequently, he invented the rotary lathe to exploit plywood's industrial potential.

Ed went on to describe the types of plywood in increasing price : Softwood made from Cedar, Firs or Spruces; Hardwood from Oak, Beech or Mahogany; Tropical from wood as the name suggests; Aircraft grade incorporating adhesives resistant to heat and humidity (most memorably used in the WW2 De Havilland Mosquito aircraft); Decorative grade made from thin veneers of attractive woods; and Marine grade made from tropical hardwood with few defects and waterproof glue.

It was startling to see how many holes and flaws occurred within the cheaper grades, all requiring copious amounts of superglue and wood dust to stabilize. It seemed as if the better quality plywood grades wouldn't be much more expensive than the Softwood plus all the superglue!




Ed discussed particular aspects to consider when working with plywood :-
Let your glue have plenty of time to really set before turning, eg overnight;
Coloured plastics may be used as laminates but roughen the plastic sheets for the superglue to adhere;
If using a doughnut ring with your chuck, glue an appropriately sized sheet of ply under the ring for a flat & secure contact;
If using a tail stock, avoid a pointed centre splitting the laminates of the ply by either gluing a sacrificial piece of wood/ply for the pointed centre to engage or else a ring type revolving centre;
Gouges will blunt quickly but shear scraping works well;
With plastic as laminates, watch buffing speed as too much heat will soften it;
Axminster supply resin-impregnated coloured wood veneers.

The September 2019 Competition was set for a turned piece(s) comprising at least 50% of a ply component.

<Competition Results>

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October 2019 - Demo 4
Handles & Feet with Graham Turner


 

 

 

Handles & feet on wood-turned pieces benefit from being curved themselves.
Apart from carving, which is not a technique many woodturners have mastered, the Turner's solutions were twofold :-
Either
turning a hollow form, then band-sawing into segments to produce several identical pieces;
or
(taking a leaf out of the last demonstration with Ed Walker), creating a laminated piece and steaming into shape against a prepared shape former.

 

A practical wood for steaming is Ash.  Graham had built up laminates from 2.5mm Ash veneers (referred to as Constructional Veneers) interspersed with 0.7mm Wenge veneer for contrasting colour.
Photos 2 & 3 below demonstrate two differently shaped formers.
Both produce flattened curves, but if desired, could be mounted between centres and their side edges rounded off.
Graham's example was a flat offset base (as in photo 3) with a cylindrical handle subsequently rounded off between its centres (as in photo 4).
Great care must be taken to ensure the flat base doesn't foul the tail stock while turning the handle.
The turner's fingers are also vulnerable so Graham prefers to put his guiding hand under his gouge rather than over the tool rest.

Steaming was accomplished in Mrs Turner's Vegetable Steamer for about 5 minutes immediately before bending and clamping against it's shape former.
(It wasn't made clear whether Mrs Turner was aware of this usage but Graham did wash it out afterwards; so that will be all right then!)

Graham then demonstrated a method for producing feet for a piece.
Always enjoying humour in his turning, Graham took the literal sense of feet.
Starting with a piece of Walnut with a hole through one end using a 25mm Forstner, he turned a lip at the tail end before hollowing out to leave about a 10mm thick wall, (photos 5 & 6).
Using an indexed chuck to delineate every 30
so that a bandsaw could cut an individual leg (photo 7), a parting tool cut was made just above the depth of the hollow so that each segment could be easily broken off the round, (photo 8).

Each 'foot' was placed between a ring drive centre (for better drive support) & tail stock to shape the leg muscle
A microplane was used to round off the toe & heel areas before back to the bandsaw in order to form individual toes, (photo 9)

 

A similar process can be employed for making handles that connect at both ends.
Photo 10 shows the various stages.
With careful design, this system allows for the connecting ends to line up flush with the outside of your turned hollowed vessel to help with a larger gluing surface.


Other options allow different handle shapes; for example, double joint at the top with a single connect at the bottom, (see photo 11)

It is important to consider the direction of the wood grain in order to preserve strength.
Handles designed with large curves are likely to have a weak section of end grain somewhere while shallow curved handles with grain from one end to the other will have more integral strength.
Choice of close grain woods like Walnut, Maple also contribute to strength.


The November Competition was set for a turned piece(s) comprising an attached handle and/or foot.

<Competition Results>

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