Yesterday I posted about turning a bit of 2″ diameter mahogany in my new Magma Titan 315 lathe and had to admit it wasn’t much of a test. Today though I put an 11″ diameter, 17″ long freshly felled log between centres. It would not have fit on either of my old lathes. This was quite a heavy chunk, and its ends were not cut square. I lined it up by eye, not very accurately as it had a definite heavy side that gravitated downward.
I thought I would try the traditional vibration test, so balanced a £1 coin (one of the few I have left after paying for this machine!) on its edge on the headstock, stood well back, and started at the lowest speed on the fast pulley. The Magma Titan 315 is not bolted down, but the coin didn’t begin to wobble until I took the speed up to about 430 rpm. I turned the speed down to about 275 rpm to begin the turning – this was not a piece that I wanted to come loose.
Here is the log after turning began. I am using the long (about 600 mm, 24″) asymmetric tool rest. It was disappointing to find it distinctly flexible towards the unsupported end. I was not really surprised at this, although I had been assured that it would be rigid.
This rest is heavily built, but it only has one stem and overhangs too far to be rigid. This makes anything but light cutting at that end difficult or impossible. Perhaps it would be better with a steel web welded at right angles to the main rest bar. This would give it an inclined T or L shape in cross section. However, a loose wooden strut slipped under the end braces it either to the floor or the lathe bed. It then becomes much more solid and will certainly be very useful. The taper helps with this as it allows for some height adjustment.
I turned a ball from the log, shown below. It will live in the garden next to the workshop door.