Club Meeting: 17 February 2016
Report by: Bill Alden

John opened his talk with a bit of history going back to a 1999 symposium where he won a prize for mixed media much to the annoyance of some  of the more experienced  turners.
He then brought some samples and asked which we felt was the most attractive. The ones adding lift to the bowl were more attractive than those with heavy bottoms.. There also needs to be a crispness and a seamless transition from one wood to the next and the overall shape needs to be followed.

The following are reasons for adding a foot or an extra piece of wood on the bottom of a bowl

1. Extending a shallow piece of wood
2. Strengthening weak bases mainly on burrs
3. Extending the bottom of a bowl which has been cut too thin.
4. Facilitates concurrent inside/outside enabling concentricity using the same amount
5. Truing up a warped bowl.
6. When bowl saving the inner core is easier to use when a foot is glued on.

Design considerations

It was also decided that a darker foot on a lighter bowl look better than a lighter foot on a darker bowl. It was decided that the reason for this being that we expect light to come from above.

Grain alignment is important. In addition to placing a foot on a bowl a second wood type can be used on the rims of bowls. These wooden rims can be cut from the outside of a bowl blank when the base is being turned.

John first lined up the headstock and tailstock using an Acculine, this is important to be able to get an accurate finish he then used a piece of teak decking offcut in the jaws using a packer for the depth of the jaws he faced it off and turned it round to the size of the bowl he was going to put it on.

John then used the Granville Harworth method of sanding which consisted of stick on sandpaper pieces onto a square section aluminium section he used two grades on separate pieces of aluminium Square section. The tool rest was used as a guide to lightly sand the bottom with the two grades of sandpaper, not much pressure was applied in this process.

This was left on the chuck and the bowl (which was a core from a bowl saving exercise) was mounted on a faceplate and the bottom trued up to the size of the pre-prepared foot leaving the bottom slightly concave which helps to stabilise the sanding process. The base of the bowl was then sanded using the same process. Grooves were then applied to aid keying of the glue. Brush or air blast both surfaces before applying the glue, he used ordinary white aliphatic PVA.

The foot which was on the other chuck was reversed into the tailstock with a Morse taper onto which was screwed the chuck. The end grain of both pieces should now be marked with a felt pen to enable lining up of the foot and the bowl. The glue was now applied fairly liberally protecting the bed with a paper towel from any glue drips. The foot is now brought up to the bowl and rotated as the glue starts to grab finally adding a small amount of pressure once the grain was lined up. The glue should be dry in about 20 minutes but John advises to leave this set up on the lathe overnight to ensure that the bond is fully cured.

The following week John brought in the bowl which was only left on the lathe until the guild closed and when turning it found that it was adequately glued and the joint was nice and crisp and accurate.

This is the method that John uses now after experimenting with lots of different methods with a recesses both 2 mm and 10 mm are using a pin off the lathe as a locator pin. He finds that this method is simple and has never had a failure.

Club Meeting: 10 February 2016
Report by: David Jones

Cam is well known for gluing things together so you can’t see the join, as well as using different coloured woods to provide both contrast and symmetry for his segmented turning. For most of us this is a particularly difficult operation, which generally ends in frustrated disappointment and often a decision that we cannot get the accuracy required so it is not worth it. Also we don’t have the equipment to do it properly and can’t afford to buy it. Cam stressed that it doesn’t require really expensive machinery, but complete accuracy to within a millimeter is needed. To achieve this he has modified his old bench and drop saws to insure very accurate cutting.

With his old bench saw he had made a new bench top from meltica, which fitted over the old top and was clamped to it, with the sawblade lowered below the original bench top. He had then turned on the saw and raised the blade up through the new top so the new hole that the blade ran in was only minimally wider than the blade itself. Cam also stressed the need to have a good quality , sharp combination blade that would cut well for a good length of time. He recommended getting it from a good saw doctor.

He would then get a piece of wood with a perfectly straight edge to act as a guide. This needed to be as long as practicable to ensure the wood being cut always ran parallel to the blade. This guide would be clamped to the bench top parallel to the saw blade exactly the width of the required cut. The blade would be lowered to just a few millimeters above the height of the wood to be cut, as this would give the cleanest cut. The wood being cut needed to be pushed through the saw at a steady rate without stopping. Using this method Cam was able to cut pieces on his old bench saw which were consistently the same width along their length and could be as thin as 3-4mm allowing him to cut the narrow bit of dark wood which he glued between the other pieces of wood to hide the joins. The cut was so clean that the pieces could be glued together without the need to further sanding. If sanding was required to make the gluing surface perfectly flat then it was done on a perfectly flat piece of corian bench top that had sandpaper glued to it.

Cam uses an aliphatic pva glue (tightbond) to do his gluing and when gluing, clamps the wood both horizontally, and vertically to ensure a tight bond and no warping.

To cut angles in the wood to make wedges (say for a clock) Cam uses a drop saw. Once again, unless the saw is very expensive it is necessary to modify it, by removing the fence at the back and clamping a flat meltica bench top over it. The saw is then brought down and a cut made along the saw travel length. Once this has been done a straight edged backing board can be secured to the new table top exactly at right angles to the saw cut using as big a triangle as possible. Other angles for cutting can then be marked with a sawcut to ensure maximum accuracy.

When cutting the wood into wedges the wood can either be clamped or Cam uses the back-board and a nail in the bench to accurately place the piece of wood to be cut. In either case before cutting the saw is pulled out so the cut is made from the side nearest the operator back towards the backing board on the bench, and the saw is not lifted out until the blade has stopped turning. When cutting wedges from a large length of joined woods it is important to label each piece to ensure that when gluing them together that one piece is joined to the correct next piece so the grain flows evenly around the finished article.

The process of joining segments for a round clock with 12 segments is to firstly join the 2 appropriate segments to each other with a third narrow dark piece of wood in between. Cam had a gig for this that enabled him to glue several sets of 2 at the same time. Once the glue had set the double sets were glued together with a dark strip between to form sets of 4. Then 3 of these sets were glued together with strips to form the completed clock circle.

Apart from making wooden objects more colorful and striking, the real advantage of this system of accurate cutting and gluing was the ability to build and turn much larger pieces than would normally be possible because of the difficulty and cost of getting really large single pieces of wood without significant imperfections.

The demonstration was very interesting and useful and showed what can be done with good preparation and how easy it can be to modify equipment to ensure that its operation will be accurate and consistent. Cam made it look very easy, but I’m sure that his 55 years as a cabinet maker helped.

Thanks very much Cam.

Club Meeting: 3 Feb 2016
Author of Article: Wim Nijmeijer

Terry woke up in the middle of the night, thinking about this demonstration!

The following morning he started the preparation and found that the blades on his thicknesser were blunt. He sharpened the blades and then proceeded to fit the blades in the setting blocks and managed to strip the threads in the process! Not a good start, but as luck would have it, Cam Cosford happened to be on hand at the right time and “offered” to prepare the blanks for the demo. Terry supplied the wood, however it was not clear what happened to the (supplied?) ebony, as it was never used in the blanks!

The blanks were made up using Teak, Bubinga and Wenge, cut with a drop saw and bonded together using Titebond PVA glue.

The first blank (outside of bowl and spigot already roughed out) was mounted on the lathe, using a screw chuck. Terry then proceeded by finishing the outside of the bowl, using a 10mm fingernail grind chisel. Turning speed approx. 1800rpm and slow travel of the chisel in order to get a smooth surface. Finally a skew chisel was used as a scraper to finish the outside. The use of a glue stick was explained for checking the outside curve of the bowl for any irregularities.
Adding 2 beads finished the foot of the bowl, and a recess was added for the insertion of a coin. (As an example.)

Power sanding (not fully demonstrated) followed using a 3″ dia mandrel.

Terry then progressed by turning a series of beads using a bead forming tool, followed by light sanding and then applied sanding sealer to the outside of the bowl. The bowl was then removed from the lathe.

The inside of the bowl will be hollowed out at a later stage, however 2 small holes (approx. 3mm) were drilled and copper nails inserted, and also some holes for a Paua insert, just to demonstrate various means of embellishments.

The second blank (similar to the first) was then attached to the lathe, using a screw chuck. A spigot was turned (48mm dia) plus a larger “bead” for forming 3 small feet at a later stage. The final outside shape was then completed. As this was going to be a lidded box, a section for the lid was parted off using a 3mm parting tool and a hand saw for the final part. (Note that the screw chuck was still in place for later remounting of the lid)

The bottom of the box was then reverse mounted. Next the edge of the box was shaped, and a “lip” turned to locate the lid at a later stage.

The inside of the box was then completed by using a 55degree bowl gouge, followed by using a negative rake scraper presented flat on the tool rest and rotated to follow the inner contour. The box was then reverse mounted in the tailstock.

The lid was then remounted in the headstock, and a rebate was turned to match the lip of the box. Next the box was butted up against the lid so that the circumference of the box and the lid could be turned and finished as an assembly.

It was noted that the laminations lined up nicely since only a 3mm parting tool was used.

A further bead was then applied to the box, and the inside of the lid was then finished and embellished using Terry’s ten-dollar tool.
Next the box was remounted in the headstock, and the lid was “jam chucked” onto it. With the tailstock in place the outside of the lid could now be completed.

More beads and knurling added further embellishment to the lid.

Terry mounted some African Blackwood and proceeded to turn a knob and a small spigot to locate the knob to the lid.
The size of the small spigot was marked on the lid by holding the center of the lid (screw chuck hole) against the rotating spigot of the knob. This left a visible mark on the lid, identifying the size of the spigot!) A good trick to quickly establish the required size of the hole for the spigot)

Finally the box was remounted again and the lid was taped to the box for security. The hole was opened up to accept the spigot of the knob. The knob was then offered up to the lid and its final shape completed.

All in all a very interesting demo with plenty of little tricks to remember, including the expert tool control and execution.
Thank you Terry for the demo.
Also a thank you to Cam, for the preparation of the segmented blanks.

Club Meeting: 21 October 2015
Report by: Graeme Mackay

Great Scott, it’s back to the future day, Ian is leading us on a long technical path from the home origins of 3D printing through to the current future. Ian feels he is in the midpoint of a long journey started in the mid-1990s. 3D printing is an exciting IT and technical movement.  Although much is held under various patents, there is still a future going forward for this medium as many of the patents are expiring.

There are many small 3D printing units available on the general retail market.  Companies such as Noel Leeming offering a $2000 unit in recent times. Ian looked at the course and said “I am going to do this myself”. He went to the net, that is the Internet, and started getting the bits to put together to make a 3-D printer. Ian used his CNC software skills to get going and joined it up with his vast knowledge of 3D CAD. A skill that started developing back in the mid-1990s and has been able to be kept on through due diligence, full application and perseverance of Woodturner.

The printing technologies have been here for a while and in various forms; extrusion printing, sintering printing and liquid polymer at the high end. So Ian headed out into the ionosphere of the blog set, open source joydem and special blogs (reprap.org).  Ian provided views of the earlier iterations of this printer. The one on display (see photo) fits into space 400mm x 400 mm x 250 mm. He made the observation that the smaller size printers are related to the size of the domestic doorway i.e. that is the amount that you can sneak through quickly before anyone sees aborted under the home.

The next but it is a demonstration walk the audience through the requirements and choices;

• deciding on the plastic type (in his case ABS)
• the need for the printer to have its own computer operation and drive
• the ability to drive from high end ST cards
• the drive for the vertical axis
• the drive is required for the X and Y axis
• the choices stepper motor
• the heated pad system for the base
• the software choices (and they were many)

Many the parts for operation were sourced from China and Taiwan with a nuts and bolts and framing coming from New Zealand the software choices were many and varied. Ian stated that it was to do was ones background skills ability and the whatever. This later to whatever covered CAD, slicing software, computer interface software is or printer firmware.

There were many trials and tribulations (although he did not mention many of the letter and detail). One of the challenges is getting to learn how to bond the layers and developed support structures to assist the printing. Examples of the printing support structures were available for view in all their complexity and provided an excellent example of the physical technical requirements to be worked out for this type of “simple” printing operation.

Ian’s explanation of the printing process and calculations were interesting to the point of mind-boggling. Solid old-fashioned direct calculation of the steps and direction is required to make a layer by layer printing workout.

A quick and simple list of some of the physical requirements to be completed provides excellent idea of the complexity of this very simple 3-D printing project:

• the direction of the steps
• printing and stop locations
• steps per millimetre vertical
• multiple steps or multiple steps (I’m not sure which)
• steps to accommodate the type plastic  being used
• steps and temperature to ensure bonding

The machinery moving the plastics extruder has to perform the correct steps and movement along the way and within the correct axis. The little example provided required 4800 steps per millimetre of height for the Z axis. The belt driven machinery for the horizontal X and Y axis required 100 moves per horizontal millimetre.

And then there’s a plastic extruder itself: an extensive technical subject with an item that has a hot in the cold end. Fan cooled to maintain the required temperature of the extrusion material. As always, in lead us up to further discussions of importance such as a grain of printed material, control of temperature in the printing zone, and a host of other things.

And the use the 3-D printed object; a replacement part to hold his daughter’s bicycle reflector.

Graeme Mackay

Club Meeting : 14 October 2015
Report by: Terry Scott

The evening started with informative information on projects the club supports –

• Wig stands for Look Good Feel Better
• Butterfly boxes for butterfly given to parents who have lost a child through cancer
• Kidz First bowls
  

For those new to the club we had a run through of how the Papakura sale of woodturning works.

The evening was to be a montage of demos of items suitable for the  Sale but because of the interest about the above was cut a little short.

A Plain Pen – demo by Bruce Wiseman

1. Start with a blank that is at least 190 long and 20 x 20mm. It is best to hold this in a 25mm chuck  but bring up a live centre for security . Or You  can hold it in the centre of a larger chuck, for this make the blank longer. Round it off.  Wind the speed up as this wood has a small diameter.
   Bruce showed an alternative of turning a dummy Mt2 on the blank; He said this made the repetition speed up as He didn’t have to take the chuck of between stages
2. With the wood round, take the tailstock away. Use the dent made by the tailstock to start drilling a 3.5mm hole 130mm into the wood. Do this gently, withdrawing the drill after each 2 or 3 mm. Then drill a 4mm hole into the first 10mm of the wood. In soft wood the 3.5mm drill may have already made the start of the hole this large. Bruce held his drill bit in an old egg beater drill but said you can also make a wooden handle.
   
3. Remove the  pin from a  4mm  rivet insert in the drilled hole and bring the tail up again.
   This prevents the timber splitting when the timber is turned to the small size need to mate up with the refill
   Now shape the pen barrel. Knobs, beads, coves, burn lines, endless possibilities.
   Bruce used the Piano wire trick to add 3 black lines
   Bruce said he enjoys making different shapes but prefers a bulge about a third of the way up
   Continue shaping and sanding until almost ready to part off at the headstock end. Apply the finish of your choice.
   
4. Part off. Remove but don’t lose the pop rivet. Finish the parted off area. Insert a bic refill.
   A pen like this sells for $8 to $9 depending on the character of the wood and quality of finishThanks Bruce well done

A small bowl suitable for Kidz First – demo  by Colin Wise

As they say there are many ways to Skin a Cat
Because of the time frame Colin had come prepared with a blank with a spigot already turned on a 150mm cylinder blank

He said he normally finishes the foot which is turned to 47mm so that the 50mm jaws grip all the way around the spigot not leaving a mark,
He then proceeded to turn the back of the bowl from the headstock side ,a difficult task for many as this was turned up hill which would normally leave torn grain to die for .He had obviously perfected this  method as a smooth finished that would have need little if any sanding at all

Next He cut a grove at the rim with  a parting tool  3mm deep .This was so that the bevel had a shoulder to rest against and if he did have a dig in the side of the cutting tip  would be pushed clear.
He used a 35 degree 13mm bowl gouge on the bevel to shape the inside of the bowl
A Teeth biting moment was then had by many in the audience as he proceeded to cut from centre out, tool upside down.

Yep you guessed it another very clean curve and finish, Sorry for doubting you Colin you sure had me sitting on the edge of my seat but be assured Ill be trying your technique on my next small bowl.
Thanks to both demonstrators that had put a lot of thought and planning into staging their respective demonstrations.
Cheers
Terry Scott