Re: X-Y Table, Rotary Table for CNC INFO

Les,

We agree on several points. Should not be too heavy. Mechanically
simple. Low profile (scissor lift Z axis fits this well!) Marketing
will be "key" to success.

All we're really talking about here is a cnc router, without the
spindle, mounted on a platform to achieve the z axis motion. Any one
of several currently existing machines could be "platformed" and "re-
marketed" into this arena... But I don't think the REAL equation will
work out the way the thought experiemnt does.

I can see that there might be some demand, but it seems that you're
not getting much bang for your buck?

But I could easily be wrong about this! Maybe a 2kilobuck
CNC "engraving and cutting option" with 10x10 travels for a BP, or
M/D would work in the market. I guess I just don't see how this
price, at the necessary performance, could be met. After all, we are
seeing retrofit prices in excess of this, which include nearly all
the same components...

The differences:
In the retrofit- the motion components are longer/larger. Assembly is
necessary. Structure is not necessary, as the machine being retro'd
provides this. Z axis no problem.(bit of a joke here; as the Z axis
is the most difficult on every machine I've ever designed,
retrofitted or worked on!)

With the small table CNC option- shorter/possibly smaller motion
components(but not if you're thinking 1k lbs forces, IMO). No
CUSTOMER assembly. Any cost savings due to smaller motion components
will be exchanged for the cost of the machines structural parts, and
assembly during mfg. Saved by using the existing machine z axis?
Either you need to retrofit IT (which crosses over into 1/3 of the
retrofit above), OR you have to implement it another way; again
expending time and money...

If you're going to sell to the BP crowd, you will need to have
accuracy at a level equivalent to what they're "used to".

I just don't see how all this adds up positive. The only benefits I
can see is that the tooling and spindle already exists. And the "Gee,
Ya mean I can set that on my BP and cut usin' the "puter"?!? (Which
may indeed be enough, IF the price/value can be met.)

Ultimately, it becomes a "compared to what" issue...

And that would be answered by: Taig, Sherline, MaxNC, etc. If the
price ends up where I think it will; you can iunclude CncJr, servo
products, and many older "used cnc's" now on the market; new enough
to be usable without retrofit, old enough to be in the price range.

The idea has merit. But I think a very REAL cost analysis and
customers needs evaluation may show that the cost to provide will be
far more than the coupla thou bucks so far expressed. (commercially;
a "garage" hobbyist can work for free! And just "think" he's makin
any money)

There's a reason that the commercially offered CNC machines cost what
they do! (I'm including the hobbyist models and m/d retrofits here.)

Hope this helps,

Ballendo


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Les Watts" <leswatts@a...>
wrote:

> Ballendo,
>
> I think such a device would have to be very mechanically simple,
> very low profile, and not too heavy.
>
> I am thinking of something that could achieve forces of 1000 lb
> or so using small servos at a modest but useable feed rate.
> That is easily done.
>
> I also think we are talking about something that costs at least
> a couple thousand dollars. Perhaps a good bit more. But might
> that not seem very attractive for someone that is looking at cnc
> mini-mills or mill-drill conversions at $10,000+?
>
> Les