Thank you, I did realise that it would be the machine, but wondered if it was likely to be the drive coupling slipping or something else, I have not taken anything apart yet, in case there are any pitfalls which is why I was asking, also I was told by another member that I would be ok without the cooling, but then he was probably not aware that I would have to do each job twice and on such a slow feed rate, Having said that the motor has never got too an excessive heat. just warm to touch.