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

On Wed, 8 May 2024 at 20:49, mike allen via <animal=[email protected]> wrote:

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

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