Re: [rp-ml] Fab@Home

From: Ian Gibson (
Date: Tue Jan 16 2007 - 05:25:04 EET


There's probably too much for me to put down in one email. Let me see
if I can be brief.

I would probably say that Marshall Burns has been the major champion
of home fabrication systems, almost from the get-go. Since he has
been promoting this, we have all waited with bated breath for one of
the big printer/computer companies to bite the bullet.

Maybe I'm expecting too much from Fab@Home, or maybe I'm interpreting
too much from the conversation on rp-ml. I'm waiting for the bullet
to be bitten and I have a feeling it will be soon. I just don't think
most people would have expected to have to build their own microwave
ovens, or printers, or automobiles; even though it might be an
ultimately more rewarding and cheaper option albeit time consuming. I
guess what we are looking at is the hobby end of the market, when
what I hoped to be seeing was the consumer end.

I think my problem is for additive fabrication to be available in the
home, it has to be a volume product. The cost reductions can
therefore result from the scale of production. To do this properly
requires significant investment in plant. RP machines are as
expensive as they are now because none of the companies are geared
towards large volume production. I am confident that if Stratasys,
Objet, or 3DS can be sure of selling 100,000+ machines per year, then
at least one version of their machine would be at least 1/10 the current cost.

In relation to the Fab@Home principle. I don't really think people
are prepared to compromise on quality, flexibility, etc. now that
they have seen what existing RP can do. Just look at how printing
technology migrated into the home. Therefore, their approach should
be based on a volume fabrication process that doesn't compromise on
quality. The use of outsourcing for all the components reduces the
risk, but also requires them to keep the components simple enough to
avoid quality issues. Certainly this applies to the critical
components like the extrusion head. Perhaps a better approach would
be to focus on the extrusion technology and produce a head that can
be fitted onto an open-source platform.

Hope this makes sense.


At 03:16 16/01/2007, you wrote:
>What's your issues with the Business model? Is it the lack of one
>or are you referring to their attempt at Open Hardware type of
>business model where the consumer has to deal with ordering parts
>from machine shops, vendors and having to assemble? In no way am I
>trying to be sarcastic or defensive, I'm genuinely curious as my
>business skills are close to null.
>On 1/14/07, Ian Gibson <<>> wrote:
>Steve, Marshall
>I read your comments with interest and have a (slightly) different view.
>- To Marshall, I would say '"don't underestimate the benefits toys
>have on other branches of technology". These days, many very useful
>software tools have benefited from getting a good start in the
>computer gaming industry. From my era, I'm convinced Jerry Anderson
>influenced a whole generation of aerospace and automotive engineers.
>Also, the toy industry is highly competitive and demanding and I'm
>sure many cost-cutting manufacturing techniques have originated from
>there. Furthermore, it is my experience that many users of toys are
>in fact young children, who could grow up to be engineers given the
>right push.
>- To Steve, your analogy is something of a Curate's Egg. In my view
>the support structure is not a problem, if you have sufficient time.
>You can always switch the material in the nozzle every time you
>require supports. However, I realise this would be very tedious and
>so there are usable limits when applying the Turing model. An
>alternative is to use a low-density approach, using a support
>structure that can be reasonably easy to remove. Very early FDM
>machines and at least one low-cost clone from China use exactly this
>approach. Also, it would be a very minor cost increase to include 2
>nozzles on the machine like current FDM. Better still, switch to
>multijet printer technology.
>My problem with Fab@Home is the business model, not the technology.
>At 01:07 15/01/2007, you wrote:
> >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
> >are.
> >
> >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
> >machines.
> >
>Dr. Ian Gibson
>Associate Prof.
>Dept. Mechanical Engineering
>National University of Singapore
>tel: +65 9277 7343

Dr. Ian Gibson
Associate Prof.
Dept. Mechanical Engineering
National University of Singapore

tel: +65 9277 7343

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