Re: Retail, Low cost CNC

>
> The question that is floating through my mind is does anyone have

good ideas on other forms of integrating the elements together? And
how much accuracy does a machine need to have for most light
industrial and hobby uses? Is a thousandth of a inch needed for
someone who is making fiberglass molds, model airplane components or
musical instruments? Would a few hudreths of an inch do? what kind
of durrability is needed for a "low end hobby" machine. obiously if
you are shelling out a grand or more you need more durability than a
black and decker but do you really need to run it 24 hours a day for
several years on end like heavy industry?


I find the 8 points to be interesting, and would have used different
words in some.

The jump from hobby to industry is HUGE.

It is pretty easy to get 1 thou accuracy from a machine. the problem
is to then do work and hold that accuracy over time.

The whole process of design needs to start with what you want to do
with the thing.

I'm working on my design of a PCB drilling machine. Drilling only,
no pretense at routing or etching.

My target is my machine parts to cost under $99.00 except steppers.

Very attainable. But, like others have said, times 5 to make a
profit and it becomes $500.00 and then 2x for lawyers and advertising
and it now becomes $1,000.

Then a hobbiest can make the same thing for $99.00 and you lose the
whole game.

Look at foam wing cutters. very flimsy construction, but rigid
enough for the application.

Look at http://www.milinst.com/robotics/robotics.htm#axis
roughly $500 USD for the kit for a complete machine.

Then look at the market.

If you are selling to industry, $20,000 for a 3 axis Bridgeport clone
KneeMill, $5,000 for a retro-fit Rong-Fu.
http://www.microkinetics.com/cncdmill.htm
to $2,000 for a Sherline.
That sets the price for a metal milling machine.

There are a few $500.00 USD machines you can buy in kit form so that
sets the low end price. albeit for light wood routing.

Look at the market. if you have a metal mill, then you have one
market with a bigger wallet than a hobbyest who just wants to cut
some wood on weekends.

Also, getting a home-brew hobbyest to fork out $$$ is often hard as
they are often buying on needs not wants. If you need a hundred
accurate holes, you can buy an X/Y table and hand crank it in your
drill press for $99.00. Then automate it to 2 axis for another
$99.00 and then the third for another $99.00 Each time you get full
use of that. and in the end have a metal drilling machine and a samll
rugged wood router.

But, a good, heavy duty home=brew router will have ball screws and
linear slides and offer something approaching 1 thou of accuracy and
cost less than $2,000 with new parts.

The question becomes who is the target market ?

And if that market wants to shell out $$$ for something they want to
build themselves.

Dave