[Chris D]

I am not a big fan of linear ways for general application machines. They work great for high speed machining and in some turning centers. It seems as though the cut-off point of performance is around 10 HP spindle horsepower (this applies to both lathes and mills).

If you have less than 10 spindle HP, then chances are good you won't run into too many problems with cutting conditions (Chatter being a primary problem of linear ways) or any problems with service life.

Beyond 10 HP, it seems as though it is very hit or miss in the industry as to whether or not you are going to have a good machine or not. I have seen some 30 HP mill cut great with linear ways and I have seen 10 HP machines that sounded like they were going to fall apart. These observations are primarily around newer machines (both at trade shows and in shops).

If I was buying a machine and these were my criteria...

Ability to cut just about anything that will fit
Ability to cut just about any material that needs machining
A good probability I won't have to deal with chatter on every tool
Good rapid performance
Heavy work weight capacity

I would choose a box way machine over linear way machines.

Box way machines just seem to perform better in a wider range of applications.

Now keep in mind, I am a fan of box way machines as I have a very diverse background in CNC along with seeing a very wide variety of applications. In other words, I HAVE to be sold on the benefits of linear way machines, AND if I am sold one, then someone darn well better back up their claims when problems arise.

Chris (who is biased towards box way machines).