Re: Is this too nuts etc

--- In CAD_CAM_EDM_DRO@y..., beer@s... wrote:

> On 25 Jan, CAD_CAM_EDM_DRO@egroups.com wrote:
> > Perfectly possible.
> >
> > I have cut threads on a Taig CNC mill by using my stepper-driven

dividing

> > head (a converted Taig headstock) to rotate the part while

milling the

> > thread out using a V-tipped engraving cutter with the right angle

of V at

> > the tip - see the penultimate photo on the following web-page:
>
> Oooh, now this I like. Especially since my current, just about
> finished project, is an indexing fixture !
>
> I bought 2 double-sided index plates with divisors from 20 to 99

and

> matching tailstock at auction for $10.00 Found some rusty but
> salvageable 4" OD 2.5" ID ABEC 10 bearings for 2 bucks a piece.

Made

> a base, a column, a shaft and a reverseable faceplate to bolt to

the

> shaft. Dividing plates bolt to one side of the shaft, faceplate

to

> the other. Faceplate is reverseable to accept my 3 jaw or 4 jaw
> chucks. Shaft bored MT3 to match my other tooling AND BORED

THROUGH

> to allow me to attack long thin shafts.
>
> In fact, I initially thought of stepperizing <?> this device, but

put

> that off until later, not knowing why I'd need to. ( That's what

the

> accurate holes are for, aren't they ? )
>
> I thought about stepperizing it again for this threading task, but
> again dismissed it and started thinking about the stepperized

spindle.

> Not sure what was going through my head, though, as the indexer is a
> lot easier to modify AND I get to use a ball end endmill instead of
> trying to grind a lathe cutter of just the right radius.
>

Alan
Have a look in the files section of this group at a file called "4th
axis 2.jpg"
This is a normal vertical rotary table with stepper fitted. In the
photo, not very clear, the job is a helical gear being cut with a
shaped 'D' bit.
I actually have this setup on the table at the moment cutting some
cam tracks in motorcycle gear selector drums. When I have done these
just for reference and out of interest I'll replace the cutter with a
5mm one [ sorry we are all metric here <g> ] and program it to cut a
5mm pitch square thread. Hopefully photo's to follow.
Another job on the list to do are some 1 /14" gas thread [ pipe
thread ] internal nuts. I thread mill these with a home made cutter
in one pass doing one interpolated revolution. This is how it's done
in industry but thread mills such as these are around $100 to $200
each. My tool costs under $5. Again photo's of the setup to come.

John Stevenson.
[ God only knows what Yahoo adds onto this post ]