Posted by BillS on June 20, 2013 at 11:24:48:
In Reply to: Re: slot on hobbing posted by Frank on June 19, 2013 at 13:26:48:
Here is an example of a special cutter that Frank is referring to:
This cutter would work only for the slotted part shown in the picture. Changing number of slots, diameter, etc.
would require the cutter to be redesigned.
(Picture provided by Inshaaje in message 7359, which can be found in message thread further down the forum under same title "slot on hobbing". Drew identified it as a photo referring to cutters specially made by Barber Coleman - publication date not given)
Hobbing is a generating process, which works well for involute gears. Hobbing gears employs rack form hob cutters which are relatively simple to make, and strong.
IMHO, I think the point to all this is that cutting one slot at a time is a reasonable way to produce a large many-slotted member. It is not a gear in so many ways! The production rate of a specific work piece would have to justify the design and manufacture of special cutters. Again, IMHO, it would seem that hobbing production would not be as fast as you might think, since the cutter seems to be less than robust, and cannot be shifted to distribute wear.
This would be a great place for folks to make suggestions about how to make a large slotted member - ideas?
For instance, I used to have a Brown & Sharpe indexing gear cutter which used form cutters and used index gears to index for nearly any number of teeth. It was Oooooold and slow, but was a great way to cut ratchet gears. Coulda cut slots, too!
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