Kees the HN350 from ERNAULT is a nice classical machine, but nothing extraordinary or even unusual to be noticed here...
The CAZE plays in a different league.
The CAZENEUVE 360 features a very specific mechanism to drive the carriage. There's no feed rod on that machine, but only a leadscrew protected by a telescopic tube and spinning in an oilbath. The leadscrew drives a worm wheel located in the carriage. If you lock the worm wheel and prevent it from spinning with the leadscrew turning, then the worm has to follow the thread and the whole carriage moves.
The locking system of the worm wheel relies on a finger engaging in a slot on a disc spinning in relation with the worm wheel. The slot and the finger both have a specific shape that allows them to act as a clutch. If too much pressure is applied, the finger is released and the feed stops (there's a little lever for adjusting the required force to release the feed). That means that you can use stops for plain turning but also for threading operations.
But that's not all. There are different discs with different number of slots. By selecting the right disc, the operator will be able to automatically pick up the thread for the next pass during threading operations (i.e. the threading lever will only engage with the carriage and the leadscrew in the right position to pick up the thread) without stopping the machine.
Threading in blind holes or against shouldered parts at ANY speed becomes possible, and the threading operations are much simpler.
And if this wasn't enough, the feed box offers an incredibly wide range of pitches without changing a single cog...
But there are also a lot of other unusual features, such as the tailstock. As you said it, the 360 BC model has a tailstock offering the operator the starwheel
AND a fine feed (just flip one lever of the starwheel to switch from one mode to another), but the tailstock also has powerfeed ! There's a feed bar on the tailstock, that you can attach to the carriage. When the carriage pulls the bar, and you're in for automatic drilling...
There's also the nice CAZENEUVE dial on the crossslide... The main dial is just like on any other lathe, but there's also another secondary dial that gives the operator the direct reading of the tenths (or thous) without having to mess up with a vernier scale. Of course, that won't replace a DRO, but from a mechanical standpoint, I find it...nice and beautiful.
These are the features and details that comes to mind at first, but the machine is widely recognized to be very user-friendly and well constructed.
Although I never used one by myself, I've pretty carefully thought about it and l'd say that the CAZENEUVE 360 BC is probably the machine that offers the most beautiful *mechanical* solutions to the conventionnal lathe limitations.
I mean the Monarch 10EE offers electrical solutions, and Schaublin did not push the ballscrew concept to its limits.
When I heard about the ballscrew thing on the big Schaublins, I thought at first that they used it to offer some sort of threading stop system and auto pick up of the thread... It seems to me that it would have been possible and may be even pretty easy. Instead of that, the "Beautiful German toolroom" thread tought us that the whole theading operation of the 135 and the 150 relies on a good spindle brake -just like on ANY no name machine - and that if you switch on the rapids during a threading operation, you loose your position ?!?! What the f **** ?! Was it so hard to design a system that would have taken a better advantage of the ballscrew ?!
Now, it's true that the CAZE is as UGLY as a fridge laid on its side... The fact that I'm french has nothing to do with it. Much less genetics (saw my name or you need better glasses D ?!
)
And it also has its weakpoints but that's another story....
and BTW, YES, you can change the feed rate while cutting...