Re: [CAD_CAM_EDM_DRO] What is wanted in a controller, was Re: Correct or Max voltage for Bridgeport Nema 42? + more...

Hi Sean,

Yeah, I replied to Carlos, missed your name somehow! Thanks for the
reply!

The URL to the 12K machine was impressive! Our hobby controller
programs are probably not going to get there!

As a hardware/software engineer, I know how to get to complex controls.
Yes, a "custom" control panel could be built. Or a pendent could be
built. But at what cost? I made one with a panel shaft encoder, and
two push buttons. Allows jogging in any axis, and rotates through jog
sizes. Useful?

More comments below:



audiomaker2000 wrote:

>
> Alan,
> It was I to blame for that long rant.
> Believe me, I would be more than happy to take pictures and provide
> copies of manuals to any developer eager to learn about how a true
> CNC controller works. I can get many varieties of both.
> The standard is somewhat as follows though....
> You have a physical control surface attached to the machine. It
> consists of buttons, a jog/hand wheel, and a display.
> Normally any G-code is done manually at the machine or loaded in
> having been completed via CAD/CAM software. The most important
> aspect of a controller is safe and effective interaction with the
> operator at the machine. It is not used as a design tool in itself
> normally although some late model high-end systems have encorporated
> this. You will have a switch on the machine that will change the
> display through several modes (MDI, Jog, auto, edit, etc)
> Each "window" will have information pertaining to those funtions.
> Now here's the tricky thing. Older systems and even some newer ones
> (Haas/Fadal) etc use a DOS style format. What the DOS style
> aftermarket programs miss though is the physical buttons and switches
> that accompany the original controls. An example would be a feed rate
> adjust knob. The actual shop floor operator hovers over a cutter and
> dials in with this knob to get just the right "sounding" cut. This
> can be done with a PC keyboard, true, but the operator must deal with
> some function on a PC. This could be overcome by software/hardware
> that would allow you to wire a real knob into the system (analog
> input) The same goes for jog wheels and other physical buttons.
> The flip side of the coin is the windows based controllers (or PC
> based really). They can do without many of the physical buttons by
> representing them on screen. Of course, in order to do this, they
> must be of a size that can be touched. In either case, a CNC control
> is no place for a mouse. You either need real buttons or virtual
> buttons In the case of a real control, that's a whole lot of buttons
> and if you had to make it work with a variety of different machines,
> you would need some serious flexibility in what each button would
> instruct the software to do. Some sort of macro writting setup
> utility would be needed.

I do several "screens" from a menu selection. I don't think touch
screen is the answer, however a few buttons and a few more control lines
could be made available with an additional LPT port. I agree, no mouse.

Screens I currently have:

Run
Jog
digitize
parameters
edit
plot

> Follow this link to a VMC we just sold...
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?
> ViewItem&item=1699565569&r=0&t=0&showTutorial=0&ed=1013226742&indexURL
> =0&rd=1
>
> This control is a 94 and lies somewhere in between a DOS based and
> Windows based control.
> It doesnt really do anything except control every aspect of the
> machine itself. If the air pressure gets low, it tells you. If the
> door is open, it tells you. It will tell you the spindle speed, load,
> etc. Almost nothing can happen on this machine that isn't monitored
> by the control which means alot of I/O.
> The control interacts with the operator in that controls needed for
> setup are in one "mode". Screens for running the cycle are in
> another "mode", Screens for editing code are in another "mode"..etc.,
> tactical devices (ie jog wheel) are real and in reach (and hard to
> miss)

This machine is greatly different then what could be accomplished on a
hobby controller program. The shear quantity of buttons!

What on the machine needs to be "watched" or "controlled"? I think
that's your custom interface!

> So how does this really differ from the hobbiest control? Well, not
> by much really. Basically it can interpret alot of I/O from the
> machine and the physical operator controls. It is safer because it
> can halt the execution of it's cycle if certain conditions are not
> met (ie door open or axes not aligned, or low air pressure (some
> spindles are air supported))
> Now this machine is a 94 and if the controller were bad you would
> probably replace or fix it, but many older machines have the same
> features but with less intuative (as in single line LED display) and
> often broken controls.
> It is because of this that you can buy full featured machines for a
> song. The electronics are often no longer supported and therefore
> expensive or hard to find. What is needed is to be able to retrofit
> these machines with something similar to the 94 I showed you.
> You wont find any professional machine being run by a mouse or
> joystick even if it has gotten cheap enough to fall into the hands of
> a hobbiest or "semi-pro".

Yeah, I'd like a full featured machine!

> Now take the pro level CNC control retrofits...
> When the control on a 10 ton machine that is bolted in place goes
> down, it's not the easiest thing to call England to fly out a
> technician at 200 bux an hour and the replacement cost of the machine
> is often 6 digits before you even think about machinery movers and
> riggers etc. By the time that 20 year old control breaks down 5 times
> in a year it has become a liability, so cost minded production shop
> owners will retrofit a 3-10k$ control in to save headaches and
> possibly even increase production. That's part of their business and
> these retrofits seem to be aim at that market.
> Meanwhile, smaller, but still professional quality machines are going
> to the scrapyard because it's just faster and easier to buy or lease
> a new one than spend 5 k on a retrofit.
> So here you are... you just bought an older pro machine for 4K and
> you are either stuck with playing with a mouse and losing half of the
> capability that it even had 2 decades ago, or spending more than half
> of the machine's value on a pro level retrofit.

> Now, don't get the wrong idea. I'm not saying the hobbiest controls
> are toys. In fact, I'm saying quite the opposite. The features found
> in some of the more evolved hobbiest's controls surpass the abilities
> of the original controls, and that's the rub. If the developers would
> recognise how close they are to controlling older pro level CNC's
> just by adding flexible I/O, then a lot of these high potiential
> older machines wouldn't be stuck between losing capability and
> costing more to retrofit than they are worth.

What I/O do you want available? An example? But the "control panel"
couldn't be custom, in order to be able to sell it.

> Some developer who is willing to create a true control, that will at
> least integrate with the machine as much as the original, and offer
> easy shop floor interaction with the operator, is going to hit the
> nail on the head and every Joe with a garage is going to start
> building really great machines from this excessive late 70's/80's
> supply. Based on the cost of these machines, the retrofit has to come
> in between 1k and 1.5k including motion control cards and computer
> which puts the software cost at about 500. This is 5 times the cost
> of some sofware out there and I think many would pay it to get
> control over a "real" machine. I know I would.
> Perhaps adding this flexible I/O to some current software is a
> monumental task. I'm not a developer so I don't know.
> What I do know is that there is a market.

I'd like to see an example of a simpler machine, and the I/O needed.
Perhaps I can get a better feel for a "real machine"

>
> Sean

Thanks for your comments,

Alan KM6VV

>
> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Carlos,
> >
> > Speaking as "one of the programmers" of a hobbyist application,
> Yeah,
> > that's about how it starts. Move some axis, first linear, then
> circular
> > and helical, add in some Mcodes, then a "plot" screen to show the
> tool
> > paths without cutting metal.
> >
> > Speaking for myself (and no doubt others), I've never seen a "Real
> CNC
> > mill" (well, maybe just a little at a trade show), so TRUE, I don't
> know
> > what it looks like and how it operates. But then, I haven't been
> > trying to "duplicate" an old mill controller (perhaps we should??)!
> >
> > And yes, I have a pendant, again, I'm sure it's not the same as on
> an
> > old mill. You mention touch screens, do the old machines have
> that?
> > For hand held computers in automotive shops anyway, the current
> thinking
> > (ours) is that you'd quickly mess up the screen! And a machine shop
> > would be a harsher environment.
> >
> > Yes, a D/A board could be added to control the spindle speed. I've
> been
> > thinking of doing that if I ever get a new Sherline mill w/ DC speed
> > control.
> >
> > What other devices ("other then S/D") were you wanting? Hard for me
> > (us) to visualize all the big guys toys! Perhaps if we could study
> a
> > machine/manual... might help!
> >
> > Thanks for your thoughts!
> >
> > Alan KM6VV
> > Central coast California
> >
> > P.S. Anybody wanna LOAN me an old machine to study?
> >
> >
>
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