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Re: #CNC gear cutting #CNC

 

Forgings are not accurate enough for a precision tool. It's got to be properly machined and tough enough to withstand the forces applied.

If you really want this chuck to last, I'd suggest the pinion be good tool steel. Aluminum won't be tough enough. And it galls easily.?

Bill in OKC?

William R. Meyers, MSgt, USAF(Ret.)

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On Wednesday, May 8, 2024 at 03:04:00 PM CDT, John Lindo <bechetboat@...> wrote:


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

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