CNC Lathes

[Cory]

Originally Posted by George C

Standard-Modern is still in business and makes great lathes from 13 to 26" including CNC versions. I believe they're still made in Canada and available in the US. They were the standard (no pun intended) lathe in many school shops for years. Loads of used ones available.

http://www.standard-modern.com/index.html

South Bend is still making lathes as well. My 9" was built in 1926 and still works well.

http://www.southbendlathe.com/

I remember looking at Standard Modern and the machines looked great... Other than being something like $18000 for a North American made model.

I believe South Bend is South Bend in name only. I recall that they were sold to an Asian machine tool manufacturer.

[George C]

Originally Posted by Cory

I remember looking at Standard Modern and the machines looked great... Other than being something like $18000 for a North American made model.

I believe South Bend is South Bend in name only. I recall that they were sold to an Asian machine tool manufacturer.

Interesting thread on the history and current manufacture of South Bend lathes

http://www.practicalmachinist.com/vb...-today-200466/

And another one on Standard Modern. Seems they're now made in Pennsylvania. Note the price of a 13x34.

http://bbs.homeshopmachinist.net/thr...-Modern-Lathes

[Brian Selle]

We acquired (as in free) a small CNC lathe early this year. I have a fair amount of experience with manual lathes and mills, but as others have said, these type machines require a knowledgeable person to set up, maintain and teach it -or- a LOT of work by someone to get up to speed. I've been pecking away at learning it for the past 3-4 months and feel capable but very slow. We now have a few programs to turn retainer ring grooves on the end of hex axles, make Colson hubs, etc but seriously... with the amount of work I've put into this I could have turned 1000 axles. The kids dig running it but we probably run it manually more often than under CNC. I just put in a request for a nice manual lathe... along with a manual mill that should service 99% of what we need.

[MichaelBick]

Cory would you mind posting some links to the 15k+ machines you were talking about? We just might be able to get the funding for a lathe that expensive, and for a machine that we would use constantly it would be a worthwhile investment into the future of our team.

[qnetjoe]

Before you consider a CNC you need to ask yourself about the tool chain that you use and how does a CNC plug into that? How do you plan to get and maintain CAM software?

Way to often I see school buy a nice expensive CNC without CAM software and/or someone that knows how to use it; then it becomes a nice expensive paper weight.

Are students going to be trained on a manual lathe before using the CNC? If not what are you going to due to ensure that your machine is not always broken? Generally I recommend that a student know how to work a manual and learns the basics before working on a CNC.

Onto the machine. I generally recommend the Haas toolroom lathes. They can be ran in a near manual mode which is good for teaching basic lathe work and then you can slowly introduce CNC concepts. One cool thing about Haas is that the control is almost the exact same between the mill and lathe making learning both alot easier and allow you to focus more on teaching machine and not teaching the CNC control system.

Hope this helps if you want to reach out to me directly just PM me.

[Gray Adams]

Originally Posted by qnetjoe

Onto the machine. I generally recommend the Haas toolroom lathes. They can be ran in a near manual mode which is good for teaching basic lathe work and then you can slowly introduce CNC concepts. One cool thing about Haas is that the control is almost the exact same between the mill and lathe making learning both alot easier and allow you to focus more on teaching machine and not teaching the CNC control system.

I love the Haas control panel, but the quality of their lathes is not great. They have serious issues holding a constant diameter when turning, small adjustments in offset (.0001") often leads to much bigger changes in actual part size, and faces quite frequently don't end up flat. I was making some parts that had to be 2.48" +/- .0004", and if you bumped the offset up by .0001", you could expect to see the diameter increase by at least .0004". It was an absolute nightmare to hold those tolerances. Keeping another part flat and parallel to within .005" was incredibly difficult as well. It took a lot of taper adjustments on the facing operation to really dial it in to cut the face flat.

For FRC purposes, these tolerances probably won't matter, but anyone buying one of these machines should be aware of its tolerance issues. They're cheap, and I guess they're decent machines, but you definitely aren't going to see the same level of quality as you will in their vertical mills (which can also be a little lacking sometimes).

[Cory]

Originally Posted by Gray Adams

I love the Haas control panel, but the quality of their lathes is not great. They have serious issues holding a constant diameter when turning, small adjustments in offset (.0001") often leads to much bigger changes in actual part size, and faces quite frequently don't end up flat. I was making some parts that had to be 2.48" +/- .0004", and if you bumped the offset up by .0001", you could expect to see the diameter increase by at least .0004". It was an absolute nightmare to hold those tolerances. Keeping another part flat and parallel to within .005" was incredibly difficult as well. It took a lot of taper adjustments on the facing operation to really dial it in to cut the face flat.

For FRC purposes, these tolerances probably won't matter, but anyone buying one of these machines should be aware of its tolerance issues. They're cheap, and I guess they're decent machines, but you definitely aren't going to see the same level of quality as you will in their vertical mills (which can also be a little lacking sometimes).

Older Haas lathes are known to be of suspect quality but the new ST and SS series are supposed to be much better.

The tolerances you were trying to hold are well within the range of what the machine can achieve. Sounds like there's something physically wrong with it.

[Gray Adams]

Originally Posted by Cory

Older Haas lathes are known to be of suspect quality but the new ST and SS series are supposed to be much better.

The tolerances you were trying to hold are well within the range of what the machine can achieve.

That was why it was so incredibly frustrating. We were running a few SL-20s, and they all seemed to have similar problems just a few months after purchase. Some of the jobs needed to be higher tolerance than what the SL-20s were specced to hold, so we ran them on our other machines without issues. It was always a gamble running jobs on the Haas machines if they were close to the machine limit.

But if the newer series are improved, that sounds like a pretty good choice in machine. The Haas control is much more user friendly and intuitive than a standard Fanuc.