Machine Speed & Gearing

Jaqkar

Registered
Registered
Joined
Dec 14, 2019
Messages
24
Hi Guys

Got a 10x24 Taiwanese lathe and trying to find out what the main gearing speeds indicated are on top of the first pic, 200/1200 etc. Is that RPM at the spindle? I take it the d & D are when the belt are on the two different pulleys as shown in pic 2?

IMG-4073.JPG

IMG-4320.jpg
 
The machine had a motor and pulley change at some stage so was wondering where these speeds are measured and if they are rpm so I could use a tacho and get it back to what it was supposed to be with the right pulleys etc
 
Yes, measured at the spindle. I believe that is correct, two different belt positions.
 
Your best bet is to use an optical tach, like mentioned above. One thing to watch out for, actually a couple, is the nameplate looks to be an English version for native speeds. The motor speed is dependant on frequency, 60 CPS in North America, 50 CPS in most of the rest of the world. It wouldn't vary that much, 3600 RPM vs 3000 RPM, but on such a machine it could be disruptive for smooth finishes.

The other point is the native motor is usually 1745~ RPM. Assure yourself that the replacement motor is the same, not 3450~ RPM.

.
 
Note that you are looking at two speed ranges, one is direct belt, the other is back gear, the two stepped pulley would result in a small amount of speed change.
 
From the top the capital D is with the belt on the big driven pulley and the speeds would be 200 in back gear (or low range) and 1200 direct drive (or high range) . Next line down would be lower case d using the smaller driven pulley for a speed of 280 in back gear and 1700 in direct drive. The next 4 lines follow suit.
 
Back
Top