Re: [CAD_CAM_EDM_DRO] 4th axis gear cutting question

First of all, you'll have to find out what diametral pitch the existing
gears are, and what pressure angle. The cutter you use will have to be one
that cuts a range of teeth, for example, you may need a 100 tooth gear, and
a 127 tooth gear (to get some multiple of 2.54), then you need a cutter
that will cut from some number of teeth that includes 100, The same for the
127. Perhaps you'll get lucky and find a cutter that will cut from 96 to
136 teeth, and only have to get one cutter. Perhaps, you would consider
making a wirefeed EDM to cut the profiles, as it's very difficult to cut
good (i.e. usable and accurate) gear profiles with an endmill... even with
the aid of CNC, since you'd probably be limited to about a 1/8 to 3/32" dia
E.M.

Truth In Information Act: I have never actually cut gears, but the above
is my understanding. Hopefully, this is not too far Off Topic, as it
relates to converting a manual machine into a (metric) CNC based system. If
it is, the listmom's will inform us, and we'll go to off-list mode, or
mlprojects group.

RayHex

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> From: Bill Kichman <billkichman@...>
>

snip. . . . . What I want to

> do specifically is cut a set of change gears for my South Bend toolroom
> lathe to permit cutting metric threads.
> I located a web based utility that permits entering gear pitch

information

> and it spits out a really cool dxf you can save to the hard drive and

finish

> tailoring to suit your thickness and other particular 3d info before

running

> in a cam app (VisualMill in my case). But is this a reasonable project

for

> my full size cnc setup and what cutters should be used?
> Also is this a reasonable job to do using only 3 axes? I don;t ahve the
> rotary table converted just yet.
>
> thanks as always for any insight.
>