Interested in adding 4th (rotory) axis - need help

[Hack]

I would like to add a 4th axis to my cnc router by using a wood lathe. The main usage of this item would be for turning spindles, round tapers, etc with my cnc router. I would also like to be able to do some inlays with this set up, so the axis has to be indexible. Looking for something with 42" Between center.

My plan is to set it up so that I can either turn it with the motor that comes with the unit, or disconnect the belt from that and hook up a stepper (if i could do this, i could index at any angle with any lathe).

Does this plan sound ok? Also, most inexpensive lathes that I am finding are only 40" and 37" between centers. (Grizzley G8691 - 150 bucks - non indexible) & (HF 42816-0VGA - 150 bucks - indexible at 10*) Does anyone know of a larger lathe in that price range?

Also, for this application, will it really matter if the spindle and tailstock taper are MT#1 or MT#2?

[Hack]

When considering software for this project, I am assuming that I can still use 3 axis cam software as the current Y axis will need to remain stationary (centered above spindle). As a result, I can control the 4th axis using Y axis controls? I really cant see where I would need full 4 axis control all at once. I will either be using a combination of x,y,z or x,z,4th axis.

How do I get the controls to use rotary motion instead of linear motion?
How do I wrap an object around the spindle? Can I just draw it like that in TurboCad (3 D of Course) and use a proper software (Maybe SheetCam - if this won't work, then what Cam Software) to do the tool paths?

Thanks all.

Hack

[2muchstuff]

Having not seen the lathes that you are interested in, what about using the head and tailstock from the inexpensive lathe and fabricating a new longer bed. I have seen inexpensive store bought lathes that use angle iron for a bed.

When using a stepper motor, use a toothed belt to drive it. Using a v-belt on a stepper is not a good idea. As for spindle tapers, go with the MT#2. There seems to be more available tooling out there to fit. If you need to go smaller for a tool you can always get an adapter.