Re: [CAD_CAM_EDM_DRO] Re: real granite machines!

Hi Jon:
My notions were a bit simpler.
I had thought to use the granite only for its stiffness rigidity and
stability.
I would be inclined to embed mounting plates for Y and Z and then bolt on
linear guideways.
Getting these dead nuts square and parallel would be the first challenge.
I would chop the saddle out of a big chunk of 7075 T6 aircraft aluminum.
I'd make the table out of a 2" thick chunk of hot rolled mild steel or
Impacto, normalized, case hardened, ground, subzero aged and then reground.
I'd bolt linear guideways on the table as well.
I'd make the head out of another big chunk of 7075, and run a bunch of
cooling channels through it.
3 ballscrews, 3 servos, all the "black box " stuff and BINGO... a hot new
machine.

Sound so easy when you say it fast!!

Cheers

Marcus
-----Original Message-----
From: Jon Elson <jmelson@...>
To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
Date: Wednesday, November 29, 2000 9:24 PM
Subject: [CAD_CAM_EDM_DRO] Re: real granite machines!

>
>
>Marcus & Eva wrote:
>
>>
>> Hi All:
>>
>> I wonder if a stone cutting company (someone who makes gravestones??)

could

>> chop out a nice "L" shaped chunk of granite for a machine base??
>> How expensive are gravestones, anyway?? Might end up cheaper than
>> patterns,castings and machining.
>
>I think a granite slab would make a great slide for a machine. Bolting and
>gluing several slabs together would be a lot easier than making monolithic
>complex shapes.
>
>I have had in the back of my mind a lathe with a huge air bearing spindle
>and air bearing slides made out of granite slabs. Sometimes, if you manage
>to be in the right place at the right time, you come across huge surface
>plates and optical tables that have been damaged on one corner. These
>could be sliced up with a wire saw into some very stout and vibration-free
>lathe beds and gantry bed mill slides. Getting them flat and parallel

enough

>for air bearing use would be a BIG job, however. You would probably
>end up building custom machinery for the purpose.
>
>Jon