Pekka- you can get very cheap D1-4 camlock backplates - is that what your machine has? You can afford to drill and tap that with a clear conscience and it won't matter if its a touch looser on the taper/register than a good one - and it will protect the register while you work. But if you go that route you still need a (3 MT?)centre to go in the 4MT adaptor, and if centering is critical it is good idea to use a soft centre and turn a new point on it.
Which is where the "keep the chuck on and turn a centre and use a cranked drive dog" merchants came in, because they are achieving all the accuracy of the above for the cost of no more than a drive dog?
Had you decided how you intended to turn/apply a cut on this slender shaft without it flexing, or can you use a traveling steady?
Hi mgj,
I wish I had a camlock chuck...maybe I could afford one if I sold all my lathes away.
I have a soft MT4 centre for the lathe, no problem there, but you brought to my attention very important point of protecting the register. I wonder if the coin would have dropped before a clacking sound? Thank you.
There are few more intricaties to be sorted out before I rush into finishing them. I might give least one of them a go just to double check that lathe turns true enough on that setup. You never know.
Making a dog should be easy, but if I order some stug from my favorite supplier, I probably order one or few. I probably could use keystock, With a clearance hole on driving pin and use low teperature release screw lock to attach this dog to finished section of the work....Or just use some brass shim stock.
I really can't believe that I never had to turn between centres before. I rather spent 45 centering the bugger on three jaw chuck that went proper way.
Pekka