Which Lathe to CNC Retro

[Deviant]

I started another thread asking about cnc'ing a grizzly lathe. I'm still in the researching phase.

But as I thought about it and was brought up in the thread. Most of the items are tossed away during the cnc process. I'm assuming that I will void whatever warranties are applied to the lathe with my retrofit. So sticking with a specific company, may not be worth the effort.

With that said, which lathe should I use. Are there some features of a certain lathe, that make it superior to another.

Also are there any other brands that use the same castings, but are more cost effective?

I'd like to get a lathe with a 1.5" spindle thru-hole. So I believe that knocks most of the 9x, 10x, 11x lathes out of the running. If there is a lathe that offers the spindle 1.5" thru-hole, please let me know. Unfortunately, most of the ones that I listed below. Do not have that feature either.

I see the following lathes on Grizzly and I'm hopeful that there are other companies that offer similar castings for less money.

With that said, there are some features that seem to be different between the lathes. I.e. d1-4 vs d1-5 chunk mounting on the spindle. Some mention gear head vs belt. I'd like to be able turn at least 20", but would expect that most of the work will be much smaller.

G4002 12x24" - 1 7/16" Spindle Thru-hole
G9249 12x37" - 1 7/16" Spindle Thru-hole
G4003 12x36" - 1 7/16" Spindle Thru-hole
G4003G Gunsmith - 1 5/8" Spindle Thru-hole

What features do I want in the lathe. Since I'm assuming that the a lot of the parts will be replaced/upgraded. I.e. halfnuts/screw to a ballnut/ballscrew setup. Is there anything that is only offered by a specific lathe from a specific company that would be worth buying?

Finally, I'm not completely opposed to buying old-iron, but that appears to be large waiting game with the potential to buy another person's problems.

Would it be better to try and building on from scratch using an existing headstock and linear bearings?

((Tossing that out there, since the stock lathes may not be the best fit for a retro.))

Thanks for any websites and information that can be provided.

[Runner4404spd]

you can basically throw away all the mechanical drive components. the biggest problem with the larger lathes is they are gear driven and noisy. the gun smith lathe has the biggest bore that fits what you need but it also is the most expensive and has the most options. i believe you can bore out the spindles on the 12x36 lathes to get you 1.5" your only taking out about .030 per side to get to 1.5"

[TOTALLYRC]

Originally Posted by Deviant I'd like to get a lathe with a 1.5" spindle thru-hole. So I believe that knocks most of the 9x, 10x, 11x lathes out of the running. If there is a lathe that offers the spindle 1.5" thru-hole, please let me know. Unfortunately, most of the ones that I listed below. Do not have that feature either. I'd like to be able turn at least 20", but would expect that most of the work will be much smaller. Finally, I'm not completely opposed to buying old-iron, but that appears to be large waiting game with the potential to buy another person's problems. Thanks for any websites and information that can be provided.

In one statement you are talking about 9-12 inch lathes and then you say you want to turn 20". A major difference.

Then you say that most of your work will be MUCH smaller than 20".

There is a reason that lathes come in many sizes.
If most of your work will be smaller, then go with a smaller lathe.

My 2 cents, Mike.