Logan Spindle Cam Lock adapter

What spindle does the Logan have? I'm no lathe expert, but I don't recall ever seeing a spindle series adapter anywhere. I expect you could fab one from a chuck mount adapter for the Logan and a cam-lock spindle head for an Asian lathe. I expect beyond loosing a fair amount of your bed length, you'd also loose rigidity.

snip----
Indeed. Extending the spindle by any fashion, especially on light duty machines, is a mistake. A good friend bought a new chuck, with master jaws, for his lathe. The original is very short. The new chuck has been the source of chatter that was unknown previously.
Harold

Since you don't say which Logan Lathe you have it is hard to give an accurate answer, except that what you are asking would not be advisable, as noted in other comments.
However, some Logan Lathes were fitted from the factory with a D1-3 or D1-4 spindle, and if your lathe is otherwise similar, a used spindle from another lathe (or in some cases, we can also provide a new spindle), could be installed.
If you can provide your Model and Serial Numbers, I can provide a more informed answer.
You might want to ask your question on the "official" Logan Lathe Yahoo Group.