Ratchet gear identification

Apr 13, 2005 3 Replies

Hello folks,



What sort of gears are used in ratchet mechanisms? I am looking at an auto-traverse gear on a Boxford shaper, which is missing a couple of teeth. I would like to make a new one.



It does not appear to be of an involute form, having teeth that seem 'square' rather than 'curved'. Would it be more closely related to a splined shaft than a gear wheel?



Because it must engage the ratchet plunger (i.e. not a pawl) in both directions - for bi-directional traverse - the gear is symetrical, with opposing tooth flanks identical.



Any thoughts? Do I need a special spline cutter, or would a mill with a horizontal 4th axis be sufficient?



Thanks for any tips.


Just square sided straight gashed slots will be fine.

-- Regards,

John Stevenson Nottingham, England.

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Thanks John. So with an appropriately ground toolbit and an indexer, I could actually use the shaper to make its own gear.

Thanks once again.

......or you could do it the easy way and simply apply weld metal into the gaps and file to shape. --

Chris Edwards (in deepest Dorset) ..."There must be an easier way...!"

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