DoN. Nichols wrote:
On 2012-04-10, F wrote:
This question will be a bit hard to answer.
With a smallish lathe (600 mm centre)and a small drill mill which module

Is that "center height", or "between centers"? It makes a big
difference in the size of the lathe. :-)

cutter set would be the best to to cut the sort of general purpose
gears? not tiny ones for model making.
one instance would be a gearbox to turn a pig on a spit.
maybe the gears on the end of a sheet metal roller or a swage& jenny
machine,or replacement thread turning gears for a lathe.
Module 1 or 1.5 or 2 etc?

Well ... I'm not really familiar with the module gears, but in
Imperial ones, for the first task (the pig on a spit) I would probably
of with something like 32 DP (Diametrical Pitch). (I've made such gears
for repairing a piece of electronic test equipment.)

For the lathe threading gears, it really depends on the size of
the lathe. Presumably, since you say "replacement gears", you should
duplicate what the manufacturer used originally -- so the new ones would
mesh with the old ones. FWIW, My Clausing (12" swing or 6" center
height) (that would be about 300 mm swing, or 150 mm center height) is
not small by hobby standards, though certainly so by industrial
standards, and it uses 20 DP (Diametrical Pitch).

By consulting a book like _Machinery's Handbook_, you can
convert one system into an approximate size for at tooth thickness (not
width) at the pitch diameter, convert that into the other system, and
find what is the closest standard size in the new system.

At present, I have no real motivation to make metric (module)
gears, because the gear cutter sets are much harder to find (at least
here in the USA) than those for the imperial gears -- and nothing which I
have needed to repair has yet needed Module gears.

FWIW -- I have a full set of the 20 DP cutters (for my lathe's
gears), and only one of the 32 DP ones, as I only needed to make one
size of gear.

Good Luck,
DoN.



the lathe is 600 mm between centres 320 mm swing (160 mm high)38 mm
spindle bore.
My question was not so much that I need any of the things that I
mentioned, just an indication of the size that I may want in the future,
I was just thinking of getting a set of cutters so that if I got a bee
in my bonnet in the middle of the night I could set to making something
and I was just trying to get an idea of which set of cutters would be
the most useful to have on hand.If I had a special job which would
require matching I would probably have to get cutters specially.
If you were making the whole set of gears you are not restricted to matching