What's new
What's new

performance expectation for live tool lathe?

meowkat

Aluminum
Joined
Aug 18, 2013
Location
IL USA
What do you guys think of live tool lathes for milling? Is it a good option, what kind of drawbacks should I expect, and what are some overall opinions?
I have bought a yet to be delivered used Mori Seiki SL-25Y with several live tool holders. Now I'm wondering what the opinion of other folks is for milling capability on a lathe.
 
It all depends on what you're trying to do. They can work great, but compared to the milling capability of even a basic VMC, they are lacking. You usually don't get many rpms. I'm guessing your machine will max out at around 3000 rpm for the live tools? And the rigidity can sometimes be a problem. But if you don't need the speed or rigidity, they are usually great... until you run out of live tool holders. The holders are quite expensive.

I think one of the big advantages of milling on a lathe is the workholding offered by the chuck. It's even better if you're bar feeding and can do your milling while the part is still attached to the bar. It gives you a lot more rigidity in workholding than trying to figure out how to hold a part after it's already cut off in a machining center.
 
Yeah you might be right about that, it's not very often on a VMC you will use a saw blade to part off a piece of work after machining it.
 
It depends. Many modern lathes were around 5k RPM and a few "real" HP (as in rated for 5HP for a short time but realistically more like a Bridgeport than a VMC). Then again, Okumas (for instance) had a real 10-15HP spindle on the live tooling.

Stickout and bar size (and obviously material) have a lot to do with rigidity and what kind of cut you can take. You are also limited on tool size in many holders and they are EXPENSIVE if you need an ER32 and all you have is ER20.

For sure go learn about polar interpolation and how it is applied on your machine (G12.1/G112).
 
I think with practice you will learn what is worth doing complete in your new lathe and what is worth splitting up into two ops. Don’t forget about cross drilling...not only milling! WMPY is right in that most of the time you get “free” work holding via the bar stock/chuck which helps (eliminates!) fixture design for parts that would otherwise be done in two ops.

I know at one point Mori’s had a cool deal where the drive shaft for the live tooling was always facing parallel to the X-axis and had a clevis that mates with a receiver on each of the individual live tools so only the tool called up/pointing at the material would spin. Many (all?) other machines have a gear box that spins all the live tools at the same time.

Good luck!
 
If you intend to do a lot of live milling, get a bolt-on turret rather than a VDI one. I have one of each, and aligning cross tools on the VDI one (an Okuma Genos L200EMY) is a bear.
 
I think with practice you will learn what is worth doing complete in your new lathe and what is worth splitting up into two ops. Don’t forget about cross drilling...not only milling! WMPY is right in that most of the time you get “free” work holding via the bar stock/chuck which helps (eliminates!) fixture design for parts that would otherwise be done in two ops.

I know at one point Mori’s had a cool deal where the drive shaft for the live tooling was always facing parallel to the X-axis and had a clevis that mates with a receiver on each of the individual live tools so only the tool called up/pointing at the material would spin. Many (all?) other machines have a gear box that spins all the live tools at the same time.

Good luck!

The Tsugamis I bought had some kind of cam system where only the indexed tool was engaged in the drive mechanism as well. I can't remember how the older Mazak worked but I don't recall seeing other tools moving.
 
The Tsugamis I bought had some kind of cam system where only the indexed tool was engaged in the drive mechanism as well. I can't remember how the older Mazak worked but I don't recall seeing other tools moving.

Was that the turret Tsugami? (M08Y or something like that?). All the live tools spin on my cross-slide Tsugami’s. (B0xxx-ii)
 
I know at one point Mori’s had a cool deal where the drive shaft for the live tooling was always facing parallel to the X-axis and had a clevis that mates with a receiver on each of the individual live tools so only the tool called up/pointing at the material would spin. Many (all?) other machines have a gear box that spins all the live tools at the same time.

On the NL series machines, the tang of the live tool is what engages with the drive clevis.
The clevis is only at the active station, while for all other stations there is a track to keep the live tool tangs properly aligned.

I was trying to find some images or a video of how it works, but it is a relatively simple concept ( of course it is so in hindsight )
 
I wonder what kind of trouble I will run into programming with fusion 360 on it? For instance, how do you choose between a C axis move and an XY interpolation? What cam software to use for this?
 
I wonder what kind of trouble I will run into programming with fusion 360 on it? For instance, how do you choose between a C axis move and an XY interpolation? What cam software to use for this?

I used Fusion. I'm not sure if the new "machine definition" feature would allow you to specify Y axis travel above which it would automatically post polar? That's a question for the Autodesk CAM team. I do know I had to do so search/replace work when I wanted to force polar, but I just replaced the Y with C and put in the G12.1/G13.1 calls and it worked.
 
My HSMworks post has a "XY_ON" and "XY_OFF" manual command you can set before an operation. I think Fusion can run the same posts. Live milling is one of the few things in HSMworks turning that actually works quite well.
 
Question about this topic guys. I had a CNC repair guy say when I was mentioning I was going to upgrade my standard 2 axis lathe to a live tool Y unit that I should set some money aside if it's not new.

I assumed he meant because of the cost of live tooling but he said not only that but if you try to push those live tools too hard (like a normal VMC) you will be replacing bearings and having them rebuilt or repaired. They are not even as big as a Bridgeport. They just wear out.

Is this true? Can you wear out live tools on a lathe trying to do normal VMC level stuff?
 
Question about this topic guys. I had a CNC repair guy say when I was mentioning I was going to upgrade my standard 2 axis lathe to a live tool Y unit that I should set some money aside if it's not new.

I assumed he meant because of the cost of live tooling but he said not only that but if you try to push those live tools too hard (like a normal VMC) you will be replacing bearings and having them rebuilt or repaired. They are not even as big as a Bridgeport. They just wear out.

Is this true? Can you wear out live tools on a lathe trying to do normal VMC level stuff?


We have a 2015 Nakamura that was purchased new. I noticed one of my axial live holders was giving me a funky finish and upon inspection of it realized that the bearings were bad. The rebuild by Koma is going to be about $1400 and a 90 day warranty. A new holder is $3300. Ive tried to come up with a system to keep track of hours used per holder but it was too cumbersome to keep track of 12 holders. I guess what the tech was saying is live holders do wear out and without knowing time in cut or type of cut with a used machine,a live tool rebuild can be costly if you don't factor that in before purchase.
 
I think with practice you will learn what is worth doing complete in your new lathe and what is worth splitting up into two ops. Don’t forget about cross drilling...not only milling! WMPY is right in that most of the time you get “free” work holding via the bar stock/chuck which helps (eliminates!) fixture design for parts that would otherwise be done in two ops.

I know at one point Mori’s had a cool deal where the drive shaft for the live tooling was always facing parallel to the X-axis and had a clevis that mates with a receiver on each of the individual live tools so only the tool called up/pointing at the material would spin. Many (all?) other machines have a gear box that spins all the live tools at the same time.

Good luck!

our yama seiki is like that also. i think most new machines are like that.
 
I wonder what kind of trouble I will run into programming with fusion 360 on it? For instance, how do you choose between a C axis move and an XY interpolation? What cam software to use for this?

we run our yama seiki GLS-2000LYS with fusion, it works fantastic!
i reached out to the guys at nexgencam and they tweaked an off the shelf fanuc post for us and it works spectacularly, was cheap too.
to change between polar interpolation you just insert a manual nc command before a toolpath that you want to use polar on and type in 'use polar interpolation'
 
we run our yama seiki GLS-2000LYS with fusion, it works fantastic!
i reached out to the guys at nexgencam and they tweaked an off the shelf fanuc post for us and it works spectacularly, was cheap too.
to change between polar interpolation you just insert a manual nc command before a toolpath that you want to use polar on and type in 'use polar interpolation'

Ha! The NexGenCam guys are down the street from me. They were great for training and support.
 








 
Back
Top