I am looking for information on half- or quarter- round
profile cutters in small [1/4 inch Ø sizes. I currently
plan on using 1/4 inch round X 2 inch HSS blanks rather than
1/4 inch drill rod [silver steel for our UK readers], with
the thought that I can grind a circular approximation of the
involute curve and make a profile cutter like an end-mill
[slot drill]. The full depth of cut for a 1.0 M/M module
gear is only 0.085 inches with a flat tip/root space of
0.031 to 0.038 inches so this seems doable. This is part of
my ongoing effort to make a complete set of change gears
[including 63T for metric transposition] for my lathe.

I have managed to locate reasonable priced "drops" of
suitable size delrin/acetel and canvas reinforced phenolic
[bakelite/formica/micarta/tufnol]. I have also invested in
a 0.025 slotting saw and arbor to gash the gear blank and
clean most of the material out before using the profile
cutter. From what I have learned half-round/single lip
profile cutters should be OK with plastics, but what about
steel? If I do decide on steel it will most likely be 1018
as one of the listed uses is gears.

From a quick internet search it appears that bakelite and
nylon/delrin are common materials for lathe change gears.
What has the groups experience been with these gears?

Any one have experience using this type/size of profile
cutter in gear making or on steel? Any
suggestions/observations welcome.

One enhancement/complication I am considering is making
provision of eccentric relief. Anyone have experience with
this and if so how much eccentric relief is
necessary/desirable?

FWIW -- the least expensive B&S style 1.0 M/M module cutters
I have been able to locate are 33$US each + S/H and I would
also have to buy or make a 2MT arbor to fit the 16 M/M hole.
Additionally, my vertical mill is light duty, and a
end-mill/slot drill type cutter should put much less stress
on it than 2-1/2 inch diameter B&S style cutter with
considerable overhang. With a 1/4 Ø 2MT collet I gain
considerable headroom.


-- Unka George (George McDuffee)
...............................
The past is a foreign country;
they do things differently there.
L. P. Hartley (1895-1972), British author.
The Go-Between, Prologue (1953).

On Jul 27, 8:20*pm, F. George McDuffee gmcduf...@mcduffee-
associates.us wrote:
...
-- Unka George *(George McDuffee)

I traded the shorter time to make a single-point cutter for the longer
time to use it. This was a reasonable tradeoff for making only one
part. Here I cut out most of the tooth space rapidly with the wrong
commercial cutter and then finished it with the right home-made one:
http://picasaweb.google.com/KB1DAL/H...10360947850418
http://picasaweb.google.com/KB1DAL/H...10370886636434

Why not make less used sizes out of aluminum? You probably aren't
going to wear out the gears to cut 27 or 44 TPI and could probably
afford to cut the occasional 11-1/2 pipe thread with many light cuts.

jsw

responding to
http://www.polytechforum.com/metalwo...ed-251478-.htm
, daniel wrote:
kb1dal wrote:



On Jul 27, 8:20=A0pm, F. George McDuffee gmcduf...@mcduffee-
associates.us wrote:
...
-- Unka George =A0(George McDuffee)

I traded the shorter time to make a single-point cutter for the longer
time to use it. This was a reasonable tradeoff for making only one
part. Here I cut out most of the tooth space rapidly with the wrong
commercial cutter and then finished it with the right home-made one:
http://picasaweb.google.com/KB1DAL/H...10360947850418
http://picasaweb.google.com/KB1DAL/H...10370886636434

Why not make less used sizes out of aluminum? You probably aren't
going to wear out the gears to cut 27 or 44 TPI and could probably
afford to cut the occasional 11-1/2 pipe thread with many light cuts.

jsw



--

Yeah I agree, this is what I would say is best.