Author Topic: Making gear cutters  (Read 2654 times)

Offline chipenter

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Making gear cutters
« on: May 21, 2016, 02:15:34 PM »
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 .
Jeff

Offline chipenter

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Re: Making gear cutters
« Reply #1 on: May 21, 2016, 02:39:50 PM »
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 .
Jeff

Offline PK

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Re: Making gear cutters
« Reply #2 on: May 21, 2016, 05:07:27 PM »
Really nice work. Very interesting to see the (often ineffable) cutter geometry evolve from a sequence of operations..

Offline chipenter

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Re: Making gear cutters
« Reply #3 on: May 22, 2016, 09:18:22 AM »
Cuts with a crisp crunchy sound and quickly , a little bit of lapping and I have a forth axis for my CNC .
Jeff

Offline PekkaNF

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Re: Making gear cutters
« Reply #4 on: May 22, 2016, 09:58:37 AM »
Smart.

How do you get the side clearance? Is the tooth embryo a little above the centre line or arbour inclined?

Pekka

Offline awemawson

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Re: Making gear cutters
« Reply #5 on: May 22, 2016, 11:34:57 AM »
How extremely satisfying  :thumbup: :thumbup: :thumbup:
Andrew Mawson
East Sussex

Offline Joules

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Re: Making gear cutters
« Reply #6 on: May 22, 2016, 11:55:11 AM »
Very nice Jeff, and totally inspiring... Moooooore pictures, they're great   :nrocks:
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Offline Alan Haisley

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Re: Making gear cutters
« Reply #7 on: May 22, 2016, 12:23:59 PM »
Are the two cutters shown identical? One and a spare? How is the worm cut?

 :Doh: Sorry to be so thick headed today.


Alan

Offline chipenter

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Re: Making gear cutters
« Reply #8 on: May 22, 2016, 02:13:49 PM »
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 .
« Last Edit: May 23, 2016, 01:12:25 AM by chipenter »
Jeff