The cutter drag could be that there was some cleanup machining
dome to the pinions after forging ?
animal
On 5/8/24 1:03 PM, John Lindo wrote:
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Mike
I
thought that they may be drop forged, but there are definite
score lines of a cutter drag ? or maybe they could be broached
?
A
female pot broach, and the pinion blank pushed from the top.?
Then
hardened and cylindrical ground.
Provided
I use the full diameter of the gear cutter, IE protruding the
blank pinion to be cut out of the indexing collet sufficiently
so at the end of the X axis travel the cutter does not hit the
ER serrated clamping ring, I may get away with it.
The
indexer head will need?to be twisted 20 degrees to the X axis
so then the depth of the cut along the pinion teeth?
will
stay the same I think. LOL??
I
will let you know soon.? musical instrument repairs are
getting in the way of this fun conundrum at the moment.
Cheers
John
I think the " Pinions " are forged in a manufactured
chuck .
animal
On 5/8/24 1:00 AM, John Lindo wrote:
Struggling a bit with the 9 tooth
pinion gear cutting.
I have only a Mod 2 12-13 T gear cutter.
My problem being as i move the cutter into the blank
pinion, the teeth wall between the teeth decreases, in
fact they are looking like a wedge
and will not mesh with the scroll gear teeth. see photo of
the parts marked 2 3?
The reason I think is even though I have twisted the
indexer to 20 deg. (40 degrees inclusive angle) as the
cutter?
moves in then the cutting diameter changes, the cutter dia
is a standard 58 mm, the teeth are only 12 mm long.
I think the the original pinion teeth of a chuck bought
from a tool supplier see photo marked 1 were hobbed, or a
special smaller dia gear cutter was used.
There may be several ways around my problem, (a) to make a
fly cutter tip with the involute form, thus greatly
reducing the cutter circumference,
the other option is (b) to CNC cut, When the X axis moves
along the 12 mm then the? Y axis? will move out 4.386 mm,
keeping the point of contact of the cutter circumference
constant. I have also machined on the lathe new pinion
blanks, making them longer as the other current problem
being the cutter hits the collet locking ring even though
I am hanging the blanks out of the collet as far as I
dare. Once finished with the gear cutting, the blanks will
be parted off to length and a square milled in for the
chuck key.
Photo shows marked 4, a double ended pinion blank, extra
long for the collet holder to avoid the cutter hitting the
serrated ring.
marked as 2 , a aluminium proto before I attack LOL the
phosphor bronze, already scrapped one piece, it was to
short anyway.
Any advise on how to get around this, then always welcome.
?
--
John
--
John
