August 2014 Newsletter

John Berkley was our demonstrator for July and his work was all based on small work.
After a short talk on thread cutting he started his first project which was to be a box with a screw top.
To make it slightly easier he chose to cut the female thread in the box rather than on the lid.
This way you have a void for the chaser to go in to that is deeper than you can achieve in a lid.

His next two pieces were to be a miniature candlestick based on antique brass candlesticks he used to restore in one of his earlier jobs before woodturning and a goblet with a captive ring.

The interest here was the home made tools he used and this is where I have probably got some of the facts wrong and I know there is one I have forgotten!!

For the candlestick one was a modified jewellers engraving tool and the other a small point tool. A round tool with three flats ground on it tapering to a point at the tip.
Iím sure most of us have got one of these.

For the goblet he used a turning tool that is ground in such a way that even his junior pupils can safely use it and to form the captive ring he had a tool made from piano wire and held in a pin chuck.

After this came another box with a screw top made this time from Anjan, sounds right but probably spelt wrong! It is a hard wood that again is good to work with when you want to form threads.
This one was made in the same way as the first one but was to have some decoration on the lid. The first decoration was a fern like design and cut using a 6Ē nail with the head ground like a v shaped milling cutter.
Captions by pictures, in the gallery, explain the rest

A couple of pointers John gave when cutting threads.
First you need a hard wood with a fine grain. Box wood, lignum vitae, ebony, the heart wood of yew and laburnum are just a few to mention.

He used a 16 TPI chaser on this occasion. The choice really depends on what you are making.

Using the arm rest makes it easier to create the circular motion you ned to achieve to cut a good thread. It is very easy to create a set of concentric circles without this rhythmic motion. (Start the music playing!!)
Cut a small chamfer before starting and follow this with your chaser to start to form the thread before cutting parallel.
Maintaining a slight taper on the thread helps when screwing the two parts together.

As mentioned, forming the female thread in the box is easier than trying to cut it on the lid.
When forming the thread on the lid cut a small recess at the base of the thread so you have room to bring the chaser out before making the next pass. This takes a lot of practice.

Next month is a club day with no demonstrator.

We have a few volunteers to man the club lathes and make whatever takes their fancy on the day and we can all talk to our hearts content.

There will be a speed turning competition in the afternoon, the subject will be announced on the day. (In other words we havenít a clue yet what to do!!)

The good news is that there will be a worth while prize to be collected by the winner.

Come along and have a bit of fun. They are always good days to attend.

Graham.



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