FAQ'S 4

Answer;

Your problems are not uncommon, especially after having availability of variable speed, and my suggestions are as follows;

Always start your threads at around 450rpm. Make sure your speed readout is correct, as double starts are normally the result of starting threads with a strike that is too fast for the speed of the lathe.

Begin your threads on a chamfer at the front of the spigot by, ideally, using the whole length of the chaser at least for the first two or three strikes. The speed at which you do this is almost certainly, as I have said, the cause of your problems. Most people want to move the chaser too quickly. I suggest around one second for each pass. This should cure your double starts.

Once the thread is begun then, so long as you allow the chaser to chase, it is fine to slow down the lathe to enable better control for short spigots.

Whilst Yew heartwood does work, there is no better wood for threads than Boxwood.

I hope this helps.

Question;

I am having some problems with my thread chasing and wonder if you can help me out?

I was inspired to start threading by your articles in Woodturner magazine around 2004, and after much practice I did become reasonably competent. I have made all of your published puzzles (magazine and book) as well as other projects of my own design.

In 2006 I installed a variable speed kit to my Record C L3 lathe and almost immediately began to have problems mainly relating to double and treble starts to threads. I did speak to you on the phone after this but sadly have lost my notes of the suggestions you made to me -- oops!!

Since then, my health has been poor and I had major surgery in March 2007 which, together with other issues, has meant that I have done very little woodturning over the past couple of years. Now returning to thread chasing I find that I again have similar problems with double and treble starts to both male and female threads. Please can you give me some suggestions to follow to try to solve the problem?

I am practising on Yew heartwood soaked in sanding sealer at a diameter of 1.5"-2". Speed is indicated as 400 rpm and tools are my well-used 16 tpi chasers which were always successful before.

Finishing and sharpening

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