Thread: How big a lathe do I need?

The first lathe that you have suppied a link to seems to indicate in its specs that it can only swing a max 110 dia over the cross slide.
The second one doesnt state in the specs from what I read as its max dia over the cross slide only its max turning dia,you may need to ask what it can swing over the carriage.
With the first on the job could be done but you would have to be working with your tooling extended out of the tool post toward the headstock due to the limit over the carriage.
Theres no reason why you could part the item off in the lathe from the inside.The only problem you would have is when it parts off your material may get damaged on the internal bore if its a critical dimension.
When it comes to your choice of chuck as long as the 80mm can hold your OD t will be fine,but if your concerned get the larger 100mm chuck this should accomadate your material.
If the second lathe can swing your diameter of material over the cross slide it would probably be the better choice.

Thank you very much for answering my question Pipeclay.
I thought the same but was concerned about the cutting tool overhanging the tool post by ~72mm, you think it might work with the hard plastic material I want to use ) I have emailed the company about that exact spec you mention. It is rather pathetic that they don't give it on the bigger machine or any of their other lathes! It is one of the most important. I have not got a reply as yet.

Thanks for the warning about parting it off. I thought I would slow the RMP right down when doing it and probably leaving it just hanging, then use a hobby knife to finish it off

Part the item off which ever way will give the desired result with the least amount of frustration or damage.
In regards to the tool overhang I would suggest using High Speed Steel tool bits sharpened to your required profiles or there abouts.
The tool bits I would then secure to the Heaviest piece of material you can fit into the Tool Post so as to give you the most Ridgidty.
Hopefully it should be ok with not much vibration or tool flex.
When you finally decide on a Lathe it would be good to have some extra material to try your cutting tools on ,hopefully you can eliminate any tooling problems before starting the part in question.