Re: [rp-ml] Fab@Home

From: steve (
Date: Sun Jan 14 2007 - 19:07:13 EET

Marshall Burns wrote:
> The Altair was little more than a toy. Even the Apple I, compared to
> business computers of the day, was little more than a toy.

I don't think this is a fair analogy.

There is a mathematical/computing theorem called 'The Church Turing
Thesis' that says that any computer with a certain minimal level of
functionality (which both of those machines had) is capable of doing
anything that any other computer can do providing you have enough
memory, and enough time.

I owned (and in fact still own) an Altair 8800 (1975)- and it was
capable of doing quite a lot - even when compared to business
computers of the time. I know of several businesses that successfully
used Altairs - (because I wrote quite a lot of software for them to
help pay my way through college!). My first job (with Philips Research
labs) was to write software to control a telephone exchange using an
Intellec-8 which was almost identical to the Altair 8800.

You can see the old Intellec 8 here:

But the Fab@Home machine has a very fundamental limitation. Being
unable to build objects with overhangs means that there is a large
set of things that it just can't make - no matter how patient you

That's a more fundamental difference than there was between
business computers and those early personal computers in the mid
1970's where the only real difference was in memory size and speed.
I believe that the first truly ground-breaking 'home fabrication
machine' will be one that can make any shape - albeit very slowly
and with some fairly restrictive size and precision limitations.

But we have to take baby steps - the Fab@Home machine is a reasonable
first effort - but solving the problem of support materials and using
dual nozzles is something that needs to be done to make a machine
that's of significant practical use. After all, if you can only make
objects with no overhangs then you can already make those things
cheaply using subtractive techniques on existing low-end CNC

This archive was generated by hypermail 2.1.7 : Tue Jan 01 2008 - 18:12:59 EET