Reverse direction turning safety

[Wood4me]

As a child in the 60s my dad took me to the Colchester Lathe Co. open evening where their machines were demonstrated. I clearly remember a young guy demonstrating quite a large lathe with a with a ‘big’ chuck winding up the speed to quite a whine and then he virtually jumping on the brake bar !!
An instant horrendous bang as the headstock spindle bent and ploughed through the gearbox. Not quite the demonstration the management had intended !
My other memory it that they had a lathe auto profiling small brass bells about 70mm high with Co. name on it that they gave to the public….. I must still have mine somewhere … anyone else got one ?

 

[Wood4me]

After a ‘near miss’ a few years ago I modified my Axminster lathe to include a positive chuck locking pin.
Also a 10 position locking pin for stationary hand sanding .
I also reinforced the bearing housing and the spindle …. I was turning crazy large lumps at the time !!

 

[Sandyn]

vfd on a three phase machine. Many of them incorporate quite powerful braking. I have a Huan Yang on my Harrison. Just on the factory default settings moving the lever from forward to stop will bring a heavy 8 inch chuck to a dead stop from 1200 rpm in about 3 seconds,

If it is a real concern, you should be able to program the stopping time on the VFD and change it from 3 seconds to something more sensible for a big chuck. It could be PD 015 to set the deceleration time and PD026 to set the deceleration mode .