MadModder
Gallery, Projects and General => How to's => Topic started by: chipenter on May 21, 2016, 02:15:34 PM
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I have been making my own gear cutters for thirty years , mostly cyclodal for clocks by the pin method , this can take some time so I looked for an alturnative , using an end mill that is close to size with some adjustments , a slice of 25mm silver steel mouted on a arbour , and gashed with a 1/16" slitting saw with the bottom on centre will give a 7 degree top rake , turned anouther 3 degrees and faced off .
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I use cutter zip from Marv Klots site http://www.myvirtualnetwork.com/mklotz/ ,for a 90 tooth 0.75 mod worm wheel gives pin diamiter of 10.3275mm
pin centre of 11.1075mm
in feed of 2.7075
a 10mm end mill was used so 0.3275 is subtracted from the pin centres , and because the top rake and the extra three degrees is no longer tangental an adjustment of the in feed is needed , dia x the COS of the angle = 0.3mm this is added to the in feed as well as half the diferance to the pin dia = in feed of 3.171 , heated to cherry red and quenched takes les the an houre .
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Really nice work. Very interesting to see the (often ineffable) cutter geometry evolve from a sequence of operations..
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Cuts with a crisp crunchy sound and quickly , a little bit of lapping and I have a forth axis for my CNC .
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Smart.
How do you get the side clearance? Is the tooth embryo a little above the centre line or arbour inclined?
Pekka
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How extremely satisfying :thumbup: :thumbup: :thumbup:
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Very nice Jeff, and totally inspiring... Moooooore pictures, they're great :nrocks:
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Are the two cutters shown identical? One and a spare? How is the worm cut?
:Doh: Sorry to be so thick headed today.
Alan
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Side clearance is because the tooth is up ten degrees from centre , the two cutters are diferent one has 3 degrees more top rake and was to big not enugh added to the infeed and is in the bin , turned a worm and mesured the angle with a piece of pinion steel , and the dividing head tilted to that cut twelve times faster than a single point cutter .