
This can cause some slight interference and noise in the gear train.
#Atlas lathe gears full
The steel and cast iron gears I've discussed have full 1/2" wide faces. One final note: the ZAMAC gears have 1/2" thick hubs and 3/8" wide faces. Divide the diameter into the tooth count + 2, thus: 66 divided by 4.125 is 16, and your gear is a 16 pitch. Example: Your gear has 64 teeth, and measures 4-1/8" outside diameter. Unfortunately for the owners of 6" Atlas / Craftsman / AA / Dunlap lathes, your gears are 24 pitch, and neither of these manufacturers make change gears to match. The part numbers for steel keyed bushings for these gears are: These gears will be interchangeable with the old ZAMAC gears. Now, knowing these numbering systems, you can search eBay or your favorite industrial parts supplier for high quality gears to fit your old lathe.

Union lists these gears in tooth counts from 20 to 129. Your 30 tooth change gear would be "CG-1630 Style K" And a 127 tooth gear would be "CG-16127 Style K". Style K denotes the 3/4" bore with two keyways. 16 is the diametral pitch and xx is the number of teeth. The letters "CG denote 14.5 degree change gear. Browning lists these gears in tooth counts from 20 to 129. So your 30 tooth change gear would be "NCG1630" And a 127 tooth gear would be "NCG16127". "NCG16xx" The letters "NCG denote 14.5 degree change gear. Boston lists these gears in tooth counts from 20 to 128.

So a 30 tooth gear would be "GB30." A 127 tooth gear would be "GB127A". You can forget about the suffix when searching. This is followed by the number of teeth and sometimes a letter suffix. "GBxx" The two letters, "GB" denote a 16 pitch gear with 14.5 degree pressure angle, 3/4" bore, two keyways, and 1/2" thick. With this in mind, all you really need to know is the numbering system used by the manufacturers. Likewise the hub and face thickness are standardized. This is the configuration that fits your Atlas / Craftsman lathes.Ĥ. The Atlas / Craftsman 10" and 12" lathes all use 16 DP gears.ģ.Ěll of the 16 DP change gears from Union, Boston or Browning have a 3/4"īore with two keyways. Bore diameter and configuration (smooth bore, keyways, splined, etc.)įortunately, there's a bit of standardization here:ġ.Ĝhange gears for the lathes in question all have 14.5 degree pressure angle. You can determine the DP of an existing gear by dividing the number of (DP) This is the number of teeth per inch of diameter at When purchasing change gears, or any spur gears, for that matter, you need to know:ġ.

A number of other industrial or specialty suppliers carry Boston and/or Browning and/or Union, and some time spent with a search engine will help to find these, but at the time of this writing (January, 2014) I've found Amazon to have the best prices. These gears often show up on eBay, but of course you can't expect the size you need to be available when you need it.

Here is my attempt to help.īrowning, Union Gear, and Boston Gear make a range of change gears that will fit these lathes. These gears are much softer than steel or cast iron gears, and not nearly as durable.īetter quality change gears are available, but the information as to exactly what to buy, and where to buy seems a bit scarce. The popular 10" and 12" Atlas and Craftsman metal lathes were equipped with change gears made of cast "ZAMAC".
