Posted by Bill S on March 09, 2002 at 00:03:23:
In Reply to: hob machine purchace questions posted by jason olson on March 08, 2002 at 17:44:33:
I'm not sure what makes a hobber a "spline" hobber other than the cutter. I'm sure there are people familiar with spline hobbers that can make the distinction. Maybe it has no feed change gears, but a "dial" feed instead?
Assuming that the machine can mount and swing a gear blank, and you obtain cutters with correct pitch and pressure angle for the gear, then you should have no trouble cutting spur gears.
Transverse pitch refers to a helical gear whose pitch diameter is the same as for a spur gear with same number of teeth. Again, the cutter must be correct for the job.
If the machine has no differential, cutting helical gears will require a machine which can mount feed change gears. Also you would need a fairly complete set of feed and index change gears from, say, 20 to 100T. If the machine has dial feed only then helical gear cutting is out.
Assuming the machine has either a differential or a feed gear train, then all you need is a method to calculate index and feed change gear sets. CPC-HOB, one of the software packages found here, is designed to do just that.
Also, you can cut sprockets (silent and roller chain) as well as any other item for which a cutter can be obtained.
There are articles and information found in the FAQ page of this site which may help you with gear cutting in general and hobbing in particular.
Hope this helps