MadModder

Gallery, Projects and General => How to's => Topic started by: chipenter on May 21, 2016, 02:15:34 PM

Title: Making gear cutters
Post by: chipenter 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 .
Title: Re: Making gear cutters
Post by: chipenter 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 .
Title: Re: Making gear cutters
Post by: PK 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..
Title: Re: Making gear cutters
Post by: chipenter 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 .
Title: Re: Making gear cutters
Post by: PekkaNF 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
Title: Re: Making gear cutters
Post by: awemawson on May 22, 2016, 11:34:57 AM
How extremely satisfying  :thumbup: :thumbup: :thumbup:
Title: Re: Making gear cutters
Post by: Joules on May 22, 2016, 11:55:11 AM
Very nice Jeff, and totally inspiring... Moooooore pictures, they're great   :nrocks:
Title: Re: Making gear cutters
Post by: Alan Haisley 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
Title: Re: Making gear cutters
Post by: chipenter 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 .