Re: [CAD_CAM_EDM_DRO] Machining Ferrite Alumina Ceramic Sapphire Quartz Silicon Nitride

This reminds me of a problem I faced about 40 years ago.

We needed a one off part to be made from Stellite (I can no longer
remember which Stellite, but it was probably Stellite 100).
The machine shop came to us, saying that their tools were wearing out
far faster than the Stellite workpiece.

'OK', we said, 'Send it to the spark erosion shop'.
The spark erosion shop came to us, saying that they'd never come across
anything so resistant to spark erosion, and that it would take ages to
form the part.

In the end, I think we had it cast.

Perhaps the following was at work here:

The Song of The Designer

The designer sat at his drafting board
A wealth of knowledge in his head was stored
Like "What can be done on a radial drill
Or a turret lathe or a vertical mill?"
But above all things a knack he had
Of driving gentle machinists mad.
So he mused as he thoughtfully scratched his bean
"Just how can I make this thing hard to machine?"
If I make the body perfectly straight
I'm sure the thing would work first rate.
But would be so easy to turn and bore
That it would never make a machinist sore
So I'll put a compound taper there
And a couple of angles to make them swear
And brass would work for this little gear
But its too damned easy to work I fear
So just to make the machinist squeal
I'll make him mill it from tungsten steel
And I'll put these holes that hold the cap
Down underneath where they can't be tapped
Now if they can make this it'll just be luck
'Cause it can't be held by dog or chuck
And it can't be planed and it cant be ground
So I feel my design is unusually sound.
And he shouted in glee, "Success at last!
This goddam thing can't even be cast.'

And to that I will add the well known irregular verb - "To Design"

I create
You interfere
He gets in the way
We co-operate
You obstruct
They conspire

On 16/04/2014 19:05, ronkline@... wrote:
>
>
> Yes Bill
> We grind almost everything with Diamond grinding wheels or Diamond
> plated plated grinding pins.( diamond is the only thing hard enough to
> cut them )
> It is possible to make some very complex shapes even with the
> limitations of the machining methiods.
> Most of these are actualy harder than carbide and the Ferrite likes to
> chip and crack like glass , especially if there isn't enough coolant
> flow on it.
> If we are still aloud to post photos in the photos section of this site
> I will put up a picture of some of the things we have made.
>
> Ron Kline