Question about keyways with live tooling

[grweldon]

I'm trying to decide if I can get by with a lathe that has only live tooling and a C-axis or whether I actually need a full Y-axis. I'm looking at a Haas as one of the choices, but the question isn't really specific to only a Haas.

We frequently cut keyways on shafts and the tolerance required is usually + or - .001 from nominal size. Can this be done reliably and with good results using only a C-axis with live tooling? It seems to me that the sides of the keyway would not be parallel, causing the top of the keyway to be loose and the bottom of the keyway to be tight.

With a Y-axis, this would not be a cause for concern and an endmill that is smaller than the size of the keyway could be used for precise size adjustments.

I have never used or purchased a lathe with live tools and I'm looking for some opinions from people who do this all the time who can speak to the results. Anybody do this on a regular basis?

Thanks...

[grweldon]

so nobody does this?

[WOLOG]

I have 2 Mori Y axis lathes. A NL-2500SY and a NL-3000Y/1250. I also have 3 Haas machines. I think the Haas live tooling is very weak and C axis will not give you true parallel sides for key ways. If you plan on using carbide endmills, they are normally a few thou under or a least Z carbs are. In my opinion, a live tooling machine w/o Y axis is very limited unless the machine is dedicated to one specific operation or such. A Y axis is basically a mill with a really fast rotary table. I would never buy a C-Axis live tooling machine knowing how much more capable a Y axis is. Plus you get to do cool stuff like running 4 turning tools per station or being able to perfectly adjust a drill pocket(boring bar block) without have to do a damn turret alignment cuz your idiot operator indexed into the part. I can post some pics if you like. One thing to remember is that a C axis will not do anything like thread milling or anything off centerline.

[grweldon]

Thank you for your reply. I'm a bit confused however. I don't understand your comment about running 4 turning tools per station or adjusting a drill pocket without turret alignment. Nor do I understand why a C-axis could not be used in conjunction with a live axial tool to do thread milling. Could you please elaborate? The C-axis is just a servo controlled main spindle...correct? Thanks again for your reply.

Glen

[WOLOG]

Glen,

check out the pictures of the quad tool holder. To use it, there is a Y axis shift for each tool and an offset for each tool. The Y axis is perpendicular to the x axis if this helps to describe it.

[grweldon]

That's pretty sweet! Thanks....