>There was some information on the South > Bend lathe list where a fellow claimed that a perfect generated tooth > for can be cut by useing a tap running on the perifery of a gear blank > and feeding across the face. The blank is left to freewheel and be > pulled around by the tap. He claims it makes a perfect tooth???
This method certainly works for making wormwheels - I have used it a number of times and the worm only needs to be a length of screwed rod the same size as the tap. My little rotary table on the mill uses 10mm threaded rod running against a brass wormwheel cut with a tap. The only difficulty is in getting the right number of teeth in the wheel as it is almost impossible to calculate properly. The wheel on my rotary took three attempts to get the right number of teeth but, since it only takes a matter of a couple of minutes to cut the teeth, that is no big deal. I put the tap in the lathe chuck and I screwed a stub 'axle' vertically into a bar held in the toolpost. The blank ran free on this axle but I had a nut on a little threaded bit at the top end to stop the blank from lifting while it was being cut. This, of course, produces a concave thread but, on a wormwheel, that can be an advantage as it gives more contact with the worm. If you wanted to use this method for cutting wheels, it would work but you would have to tip the blank over to the helix angle of the thread to get straight teeth and move the blank vertically as well to get teeth which are even across the wheel. Of course, you may be able to consider making helical gears but you would need both right and left hand taps for this. ------------------------------------------------------------------------------ The NEW KODAK i700 Series Scanners deliver under ANY circumstances! Your production scanning environment may not be a perfect world - but thanks to Kodak, there's a perfect scanner to get the job done! With the NEW KODAK i700 Series Scanner you'll get full speed at 300 dpi even with all image processing features enabled. http://p.sf.net/sfu/kodak-com _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
