Re: [CAD_CAM_EDM_DRO] Bridgeport CNC Mill???

Jon .. Everything you say is correct, as usual.

However, there are drawbacks to the route of your hw and EMC2.

He would go from a single source of very expensive parts (the original
Anilam stuff, which is what I referred to) to a single source of hw, the
pico systems stuff, that ONLY works on EMC2.
Absolutely no criticism implied - your know-how is without a doubt, and
the hw apparently performs quite well.
Yet, experience has shown that single-sourcing anything is problematic
in the medium to long term.

However..
EMC is limited in terms of hw speed, unless you go into the expensive
stuff, just as you said.
The mentioned servo loop update time, 20 khz max, is low for high
resolution stuff.
The high end stuff is not well documented, and making any changes into
the screen stuff is hard, practically impossible, unilke with mach3
screen designer.
EMC installed base for higher end stuff is very, very low.
Plugins are few and far between.
Apparently the MESA stuff, some is implemented and some is not. Some is
very expensive.
Similar with Mach3 and MESA or Galil stuff.

The OP woudl not need this - for a basic 3D mill, in all likelyhood,
nevertheless it is there.

As an example, I am using 100-200 kHz hw update rate and will be using 1
Mh to 2 Mhz, in the near future.
On a lathe, with a Centipede, and mach3.

A user can be up and running very easily and quite cheaply with mach3,
with about 50.000 commercial customers, and perhaps 2-3 times more hobby
users, and a vast, responsive, growing community of enthusiastic supporters.

If I myself needed a basic, cheap, servo 3D milling machine, I would
probably use your servo controllers - despite the fact that I have very
machiliar with mach3, for 8 years, and feel it is excellent for what it
does.
The biggest drawback on mach3 is it´s hidden, dependency mechanism for
all advanced higher end stuff.
Now, if money is allowed, very reliable brushless servos etc. exist for
either environment, with any resolution, speed and power you care to pay
for.

So, a bit like cisco routers, you can do anything from a vast list, with
mach3 or EMC2 but you definitely cant do all of them at once. And nowing
what you can and cannot do is (in truth) impossible.
Nevertheless, for more advanced stuff, similar difficulties exist with emc3.

The biggest advantage of EMC2 is the non-dependency structure, where
practically nothing depends on anything else.
So most products will work with most products, so buying advanced x wont
cripple anything else.
This becomes very important when the machines or the parts get expensive.

The biggest drawback in EMC2 is lack of an easy erector set cookie
cutter customiser, a.la. screen designer in mach3.

No-one who makes money with their machine (this was not the goal of the
Original Poster) minds buying a set of x, say 3 servo drivers, at 1000$
each, when this raises machine productivity, and results in paying for
them in a few days.
However, when such products then wont work with (real random examples)
dual-gantries, homing, threading, dual home switches, rear tool post,
dwell, torch height control, cutter radius compensation etc etc everyone
minds very much.
The problem is not one of reliability or functionality - it is that you
cannot know, in advance.
Only Very experienced people will even suspect that these problems exist.

Having a basic cnc milling machine is typically about 2-3000$ in parts,
when all is said and done.
Electronics, pc, cables, bits and bobs.
In this, 200-400$ here or there is immaterial.
Cutting corners is sometimes possible, but almost never a good idea.
Examples of this are old steppers motors, old laptops, no
guides/protectors for cables, no limits, poor wiring practices, old
electronics, and so on.

Some of us who have been doing this a lot can do so safely with good
success.
We are also able to diagnose the problem to the correct cause, and
mostly have extra drivers, steppers, servos, psus, bobs etc lying around.

It is never the best, easiest, cheapest recommendable solution for a new
person just starting out, in my opinion.
If someones wants to learn to assemble machine from bits of stuff, this
is the correct route.
It is slow, frustrating, hard, expensive and replete with hard knocks
and (semi) expensive errors.

The best thing I did was first build a 7x lathe, twice, from cheap
components. Best because I learned what not to do, cheaply (a few
hundreds of EUR), quickly.
The second best (absolutely succesful choice, btw) was buy an industrial
tool post for it, from the beginning, and the same tools, posts and bits
are still in use on my next, industrial, 1 micron, 12x cnc lathe.

PS-
I am not saying EMC2 is weak. not at all, on the contrary.
I have been a long time linux user, running mission critical production
on servers I own and manage, for about 10 years (14.000 simultaneous
users, for 140 major companies, worldwide, at once).
I find it relatively easy (complex and slow, but not hard), and very
reliable. I also find it quiet expensive to get there (but much cheaper
than the alternatives).

The point is, mach3 is much easier, simpler and faster to get up and
running for a new guy.
Either one will work just as well for milling in 3D.
Both are very reliable.
Both are very powerful.
Complex powerful advanced stuff on either is hard and expensive.
3D 3-axis cnc milling is easy, simple and cheap.

There- in 6 sentences !

> "hanermo" - CNC 6-axis Designs wrote:
> > Mach3 is maybe the nr1 most stable Win xp app of all time.
> > I have some idea, as I used to be the tach mgr, and repaired maybe 3000
> > pc´s with my own hands, and helped assemble (oversee) over 10k builds,
> > for which I bought the kit from all over the world.
> >
> > I would recommedn mach3 as a cnc controller.
> > Forget the anilam.
> > Rock solid, cheap, reliable.
> >
> > The problem you have is many-fold.
> > Your servos are likely good - but they are probably not easy to get
> > working with mach3.
> >
> Well, EMC2 is also rock solid. I've been using EMC since 1998, and EMC2
> since it
> came out. I have NEVER had a crash, lockup or abnormal behavior that
> could be traced
> to the software since 1999 or so. I use it on my production servo
> Bridgeport to make
> some of my EMC-related products.
> > The problem is probably that your servos use either velocity, +/-10V
> > analog to control them, or something like that that.
> > They may also use resolvers rather than encoders.
> > Nothing wrong with it, works well, it´s just that the parts are very
> > expensive.
> > Think 500-1000$ per axis.
> >
> No, not at all necessary. My PPMC interface starts at $780 for a 4-axis
> system, and includes
> essentially everything to interface the entire machine, assuming the
> servo amps are
> good, and the encoders provide digital output, as opposed to analog.
> That breaks down
> to $260/axis, assuming you only want 3 axes.
>
> If your amps are shot, then a better choice is my PWM system, a 3-axis
> setup is
> $250 for the 4-axis controller and $125 per axis for the servo amps.
> That is
> $625 or $208/axis.
> > Hobby servos use almost excusively step and dir to control them, and so
> > do many industrial ones.
> > Cheap, easy, reliable.
> >
> >
> And, every time you E-stop, you have to re-home the machine. With
> either of my systems,
> you can go to E-stop any time, such as when changing tools, and never
> lose the axis
> alignment.
>
> Jon
>
> __._,

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