Re: [CAD_CAM_EDM_DRO] Re: RepRap

In "Foundations of Mechanical Accuracy" they describe
how to make a surface plate with no reference surface.
It involves grinding three square or round plates together
in a certain order. If done properly the three plates
will grind each other flatter and flatter. There is no
theoretical limit to this process. You can go to optical
flatness and further. All done without precision machinery
or measurement tools.

The process was invented by a Frenchman in the late 1700's
as I remember.

Once you have a perfectly flat surface, it is easy to do the
step and make a precision machine tool ;-)

The book is available here;
http://www.mooretool.com/publication.html

Pete.

----- Original Message -----
From: "Jon Elson" <elson@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Friday, January 12, 2007 9:43 PM
Subject: Re: [CAD_CAM_EDM_DRO] Re: RepRap


> Tony Smith wrote:
>
>>>>Thanks. The "self replication" stuff shows up all over that website
>>>>and is put forth as a primary benefit, hence my question
>>>>
>>>>
>>>and comment.
>>>
>>>
>>>>Pete
>>>>
>>>>
>>>>
>>>Hi Pete,
>>>
>>>I agree with you. No machine can really replicate itself, not
>>>even a Bridgeport. Somebody pointed out the self-replicating
>>>
>>>
>>
>>
>>Apparently you can make a lathe on a lathe. Possible since you can do
>>milling on a lathe, but not vice-versa. Whether the one you make is the
>>same as the one you used to make it is a different matter.
>>
>>
> I can't possibly imagine how you could make a lathe bed on a lathe.
> Milling in
> the lathe is generally for very small parts.
>
> Of course, with the proper hand tools, you can make a very good lathe bed
> using no power tools at all. But, that is a SLOW and laborious process
> (don't
> ask me how I know this!)
>
> Jon
>