- Joined
- Nov 21, 2012
- Messages
- 793
RAY
Much appreciate the research on this.
"Tis good to listen to someone who has sold Lathes almost all his Life.
What does concern us a bit though is whether the SPINDLE BEARINGS would last the distance on this "VARIABLE-SPEED" driven Machine. U see, the Manufacturers stated top speed with the INVERTER is 2'000 RPM. We asked for this to be increased to 2'500 RPM with an similar increase in size of the MOTOR from 2 HP to 3HP. They agreed, obviously at a Price. However, we really don't know if that is what we will really get at the end of the day. We need the extra "Voom" more for very light finish cuts and POLISHING. Our present 14 x 40" running at 1'800 RPM top speed, does give us very satisfying Finishes, although it seems like we are pushing things a bit when it comes to continued POLISHING at these maximum speeds. We are working quite a bit on S/S and Ti and these Steels can be rather demanding both on machine and Labour.
Come to think of it, most of the top Branded HIGH SPEED Machines like the Hardinge copies ie., Eisen, Sharp and Cyclematic including the UK old stalwarts Colchester and Harrison are all today made in TAIWAN. So for us, there just might be a scare of the unknown factor lurking like a phantom.
Although this manufacturer we are dealing with may not be a top end Machine Supplier, we are sure, they are however exposed to the Standards of their competition and contemporaries in their own Country.
It all might just get together evenly.
Would like to know what U think.
Thanks again, graciously.
LORD BLESS
aRM
Splash lubrication is sufficient even for higher speed machines. My Colchester Chipmaster has a top speed of 3000 rpm and has a splash lubricated headstock. The headstock oil I use is Shell Morlina S2 BL 10 (which is the recommended oil). This oil has a viscosity of 10 and is pretty much like water.
At these speeds, the quality of your lubricant, size of your spindle bearings and stability of the machine is put to the test. This also means that the chucks you use need to be rated for these speeds and then you start talking higher level equipment. Both my 3 and 4 jaw chucks are rated to 3000 rpm and would likely cost the price of a cheap hobby lathe on their own so it's not simply a case of increasing the speed of a machine.
You really need to invest in good oil and keep a very strict maintenance routine when you start talking higher speeds. Regular checks are necessary at each day and checking that chucks and work are secure become critical. A 4 kilogram chuck spinning at 3000 rpm becomes an unstoppable missile.
I don't think it would be a problem to increase the speed to 2500 rpm, provided the mass of the work you turn is not too high or unbalanced as this would put a lot more strain on the bearings.
Paul.