Question for Wood Turners

[Gary Campbell]

I am looking to build a CNC kit that would be a "bolt-on" to an existing wood lathe. A CNC "copy lathe" of sorts. Having no wood lathe experience I am a bit lost as to which size class of lathe to make the build for.

My first guess would be to go for the 14-42 class with 2hp 220V power, as I feel that stair builders, custom bat providers, game call makers, etc. would be able to use it on a regular commercial basis. That said, I don't have a clue if this class is popular, sells more than any other, or hardly sells at all, due to the fact it is the highest price range of all on most of the popular online sites.

For those of you that might or could put something like this to work, what would be your preferred platform?

[Dennis Ford]

I have considered the same idea. If your target is hobbyist turners; consider making one for the Jet mini lathe, I think it would be great for decorative boxes and fancy finials. For semi-pro turners making the items you mentioned; the Powermatic 3520 would be a good choice but I expect that you would get requests for models that fit several other machines. I very much doubt that it could compete with manual turning for speed on round shapes but it would have great capabilities for spirals, ornamental work, etc.

[Gary Campbell]

Dennis...
Thanks for the info. Yes I plan on looking at a smaller version in the future that can be a bolt on for smaller lathes. When you say "I very much doubt that it could compete with manual turning for speed on round shapes but it would have great capabilities for spirals, ornamental work, etc." I assume that you were talking about an indexing head. I am not looking to do that. I am looking to make a kit that one can add to an existing wood lathe to make cuts similar to these made on my prototype rotary: https://www.youtube.com/watch?v=_yznJrzd730&list=UUl3fUyY3Nq1H5E9wEAzld2Q

Not being a turner, I have no idea about the speeds that were cut in the video above, but repeatability must be needed in many cases, and that part in the video can be cut in 2 minutes and 20 seconds. I don't know if the 1/8" cut depth (1/4" on diameter) is a lot, little or just right.

[roger oldre]

Terrific! what do you use for cad/cam? I tried to get my dad to convert one of his lathes in the early eightys with a bandit control. He didn't like the idea of learning "computer stuff"

[Dennis Ford]

Dennis...
Thanks for the info. Yes I plan on looking at a smaller version in the future that can be a bolt on for smaller lathes. When you say "I very much doubt that it could compete with manual turning for speed on round shapes but it would have great capabilities for spirals, ornamental work, etc." I assume that you were talking about an indexing head. I am not looking to do that. I am looking to make a kit that one can add to an existing wood lathe to make cuts similar to these made on my prototype rotary: https://www.youtube.com/watch?v=_yznJrzd730&list=UUl3fUyY3Nq1H5E9wEAzld2Q

Not being a turner, I have no idea about the speeds that were cut in the video above, but repeatability must be needed in many cases, and that part in the video can be cut in 2 minutes and 20 seconds. I don't know if the 1/8" cut depth (1/4" on diameter) is a lot, little or just right.

I was thinking that it would use a live tool (router?) and be capable of 4th axis work. It is faster than I expected.

[Gary Campbell]

Roger...
I used Vectric's VCarve Pro for design, and showed how I did it in post #6 of this thread: http://www.sawmillcreek.org/showthread.php?217716-SideWinder-Lathe-Indexer

Dennis...
There are plenty of indexing option out there, both OEM and DIY, so even tho my SideWinder is a robust indexing axis, I concentrate more on machining type and turning options. Indexing and turning have vastly different requirements, but most indexer purchasers seem to think that they will work well at turning speeds. On small machines this is seldom the case, as most router/spindle (live tool as you refer to) heads seldom cut wood above 300 ipm, where in a lathe a 3" diameter blank would rotate under 32 rpm to maintain that same surface feed rate.

As you might expect, the force on a lathe tool with a blank rotating at 2000 rpm+ are 8 to 10 times what is on a typical router in a small cnc application. My SideWinder combines both and seems to do both very well, but makes the flat table portion of the machine almost an afterthought.

[Gary Campbell]

Guys...
Sorry to be a pain, if I can know what I am seeing, there are 3 "multi speed" drive versions on different branded lathes.
1) 2 sets stepped pulleys and fixed motor rpm
2) Lesser steps on the pulleys, but VFD gives variable speed to the motor, in a couple rpm ranges
3) A variable speed lever that changes speed thru a single range

For turning rounds, like spindles, bats, etc. where my cnc knife would excel, which is best, and if you don't mind, why is that your preference?
Thanks for your time, Gary