Thread: Are Chinese machines really improving?

Originally Posted by cba_melbourne

Below 10" swing quality is simply nonexistant. 10" and 11" swing lathes are still quite poorly made, but at least two steps up from a 7" minilathe or a 9x20. In the 12-13" range you can find some crap at the cheap end, and some better made models if you look at the top of the price range.

I thought you were a big fan of Seig lathes ?

But then red paint doesn't make a good lathe.

Beats me how these model engineers make anything decent with their inferior crap Chinese lathes.

Rob

Originally Posted by nearnexus

I thought you were a big fan of Seig lathes ?

But then red paint doesn't make a good lathe.

Beats me how these model engineers make anything decent with their inferior crap Chinese lathes.

Rob

Triumph of skill & persistence over machine I'd say.... just like fighting with a worn out 'quality' machine.

PDW

Originally Posted by Ueee

I for one would be very cautious using a machine with 10hp that only weighs 420kg. I do hope actually that the 7.5kw is a typo.....

Ew

Ew, it's the same way how industrial CNC machines are setup, applied to a manual lathe aimed at training and prototyping. It is what most people hoping to upgrade their lathe to VFD dream of, before checking the size of their wallet. Let me explain. When running a CNC lathe, it would be too difficult to have the software change spindle speed gearbox levers. What is required is a completely stepless variable speed control, providing the required cutting power for any possible application from standstill to the very high rpm needed to use modern tooling. The spindle drive of modern machining centers can even index, just like a servo motor. A powerful AC servo motor that is.

The EMCO 14 is not a CNC machine nor can its spindle drive index. But it is a modern manual lathe, and as such does not use a simple VFD and gearbox like we hobby guys do when upgrading an old design lathe. It has infinitely variable spindle speed, meaning no gearbox or step pulleys. Hence it really needs a 7kW VFD drive to ensure it has still adequate power at very low speeds. In addition it has constant cutting speed and an electromechanical spindle brake spindle brake. The specs of this spindle drive are impressive. You may want to download the brochure, there you will find this diagram about the spindle performace:

Emcomat_14D_Spindle.jpg

With 40% duty cycle, 35Nm torque from standstill to 2300rpm, then dropping off to 10nM at 4200rpm.

With 100% duty cycle (eg continuous running) 20nM from 0 to 2500rpm, then dropping off to 10nM at 4200rpm.

Keep in mind this is a 14" swing lathe, that is an impressive top speed.

If you wanted similar performance on a 14" Chinese lathe with single speed gearbox, you would too need a 7kW VFD and motor. The problem is, such a drive would cost more than the lathe.

In anticipation of the next question: the EMCOMAT-14D costs about $20K. It is the successor of the well known and highly regarded Emcomat Super11, and it is the smallest lathe in todays EMCO Mayer range. The Super 11 did cost about half that much some 20 years ago, and was at its time what many home machinist was dreaming of. I guess back then, one had to save just as long to afford a Super11, as one would have to save today for a 14-D.


EDIT: oops I just notice the 14D has two speed ranges. 60-2000 and 2000-4000 rpm. Else I guess it would need a 14kW drive...


http://www.emco.co.uk/product/emcomat14s14%20d

Originally Posted by cba_melbourne

In anticipation of the next question: the EMCOMAT-14D costs about $20K. It is the successor of the well known and highly regarded Emcomat Super11, and it is the smallest lathe in todays EMCO Mayer range. The Super 11 did cost about half that much some 20 years ago, and was at its time what many home machinist was dreaming of. I guess back then, one had to save just as long to afford a Super11, as one would have to save today for a 14-D.

I paid $3500 for my Emco Maximat 11 lathe 14 years ago. I'm the 3rd owner and it's as new - first owner bought it new when he retired to build a live steam loco, 2nd owner used it to make pins & bushings on his farm. I got it when he was getting divorced because I was the only one not trying to screw him on his price. Probably done less than 50 hours on it in the time I've owned it - it's my backup lathe and the only single phase one I own.

They are very, very nice machines but - IMO - a bit light weight in the castings if you want to hog off metal. But I compare it to a Chipmaster which masses nearly 3X as much, and it's lightweight compared to a Monarch 10EE.

I agree with the comments about power - drop the spindle speed and watch the torque follow. You *need* a big motor just to deliver that low speed torque. If I ever off the Kopp variator in my Chipmaster I'll look seriously at fitting a 5 HP minimum, 7.5 if I can make it fit. Just to get that low end torque.

Now if the Chinese could build the equivalent quality for say $3000 in 2014 dollars - that would be a bargain. Fat chance though....

PDW

I would like to clarify my position in relation to my previous post regarding Chinese Machines, it has been suggested to me by a fellow forum member that my post could be viewed as I was touting for business. I can assure you that this is not the case. I only mentioned my agency as a way of leading into my experience in dealing with a Chinese manufacturer at a close level and so I could demonstrate that I was talking from a position of firsthand knowledge.

Cheers.