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

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?


audiomaker2000 wrote:

>
> Thanks Carlos.
>
> I guess what really bites me is that the developers of these 100-300
> dollar apps get so darned close and then miss it.
> In addition to owning my own shop, I am a small machinery dealer and
> a buyer for a major machinery dealer.
> The trend right now is that you are finding tons (literally) of 70's
> and 80's CNC's being dumped by local shops and the government and
> really there's nothing wrong with them aside from broken or outdated
> control electronics.
> I'm sure I'll get into hot water for saying this, but this is my
> second investigation into retrofitting machines and what I am finding
> again is that there is this void that could be filled between free or
> shareware controllers and mega-bux professional retrofits.
> The sad part is that the "hobbyist" apps have reached a level that
> they could subsitute and surpass the original controls but don't
> allow the flexibilty to control "real" machines.
> It's like they start out to see if they can make some axes move and
> succeed and then go off on some tangent off playing with graphical
> toolpaths and other fun stuff without really ever completing a true
> controller. All one has to do is actually look at a physical CNC
> controller to get the idea. You don't need toolpath simulations and
> gimicks (these are normally done in people's CAM apps anyway) What is
> needed is a close-as-possible representation of a real controller on
> a PC.
> Since this usually negates the original physical pendant hardware,
> you have to make up for that somehow.
> This is probably best accomplished by the use of touchscreens and you
> would think that "controller" software would be designed around such
> devices since they lack any other tactical interactive hardware aside
> from a mouse and keyboard. You'd have DRO's you could read from 3
> feet away and big buttons you could push on a touchscreen.
> Basically "virtual hardware". The sofware would have to be able to
> control switches (which it can already), Step and direction (which it
> can already), and some sort of DAC (which most cant).
> Well, these low cost apps are very very close but still limited
> because they lack the configurability to interact with devices which
> can do more than S/D.
> Of course, there is CAMsoft. (camsoftcorp.com) They got it right. The
> software looks and acts like a controller and supposedly you can
> configure it to work with all sorts of I/O..including LPT. The
> problem is of course that their market is not the retrofitter who
> wants a nice CNC from a 3000 dollar 80's machine, it's production
> houses who want to get a 75,000 dollar machine back up and running
> because it's costing them a couple grand a day to be down.
> Hence the void.
> Of course everyone will jump up and say "you get what you pay for"
> and all that, and it's true unless what you are paying makes no sense
> for the machine you are fixing and it's uses.
> So that's the killer here...
> Again, these once "hobbyist" apps are sooooo very close to filling
> this void but they seem to fall just short (even though they keep
> improving the apps in other "fun" ways).
> Basically you need ...
> Step/Direction
> Rotary encoder input (for jog wheels and feedrate)...(this *could* be
> done with mouse encoders)
> Touchscreen minded GUI (which means at least the GUI will be windows
> based)
> Shop floor minded DRO (some do)
> Tool changer routine (configureable via "if-then" based on input
> signals"
> More than 4 switches and at least 1 DAC for VFD/spindle drive control.
> Multiple screens for multiple modes (like a real CNC. Why does
> everyone try to make everything fit on one screen?
>
> What does this do? It allows people to build real CNC's with modern
> controls inexpensively from endless amounts of "outdated"
> professional machines. Something above the MaxNC's and Sherlines, but
> perhaps not the Haas's, Fadals, and Mazaks that the big production
> houses need.
> Not free, and not 5 grand... maybe about 500-600 for the software and
> figure another 600-700 in hardware. Then you slap 1500 into your 3000
> used machine and have a nice setup for "semi-pro" use.
>
> Ok, there's my rant. It is a result of researching retrofits once and
> giving up only to return once again and find there is still a void.
> Of course, it's possible that this does exist, but so far I haven't
> found it.
>
> Apologies for the babbering.
> Sean