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

Hi Sean, List,

Just looked at the pix, and the dynapath display is perhaps a little
more in line. Looks a little like the one Fred posted of his machine.
It would still be a tough road to make a generalized
controller/interface for a machine like this.

There certainly is a great deal to be learned from a machine like this!
Again, $6K, and the size hold me back (otherwise, fools rush in...),
yeah and my wife!

All these extra controls, jog, feed rate override, doors, jaws,
spindles, lube oil, air, etc. Seems this is a "control" in it's self!
Possibly this is a project to it's self!

the levers and jog wheels could be a "pendant" project, and added to a
controller.
The D/A could be worked in as well.

Tach? I have Dan's tach, but it has LED's, not a computer interface.
These and DRO encoders could also be a separate project (they kinda
are).

I'll get to a driver and controller for my RF-31 eventually, It could be
a candidate for a more "complete control" as you describe. Then one
would be practically designing an entire control! Something I'd want to
take in stages. The mill's big enough, so that I wouldn't mind having a
19" rack mount controller sitting next to it (I've got a control panel
from something, lottsa switches and an E-STOP switch). Too much to put
next to or DO to the little Sherline!

And if a sufficiently complete controller is built, perhaps it could
apply to some retrofits as well!

Thanks for the ideas and pix!

Alan KM6VV


audiomaker2000 wrote:

>
> Alan,
> I suspect you are correct that hobby controls wont reach this
> complexity. I used this VMC as a model of what semi-modern CNC
> controls look like. Keep in mind though that 90 percent of those are
> buttons that a standard PC keyboard would take care of. If you wanted
> to be really trick, there are flat programmable keypads for point of
> sale that you could mount directly to the face of a pendant for
> around 150 bux (you print out a top cover that goes over the whole
> keypad, laminated it and program the buttons below your symbols or
> custom printed keys) I have two of these I hope to incorporate into a
> custom control. There are probably 8 or so actual contact type
> buttons on that machine and a few of those could go the the PC as
> well. The major input devices that should be physical are the jog
> wheel (remember that most of the controls have this and it would be
> best to make it reusable in the new control), feed rate overide, and
> the number one....toolchanger (which actually isn't a button but a
> series of I/O events).
> There are so many different configurations and therefore it has to be
> up to the individual to create their own circuits and control panels
> to suit their machine and how complex they wish to get, but $100
> worth of Radio Shack switchs, pots, and relays would go a long way.
>
> So I'll probably forget a couple but...
>
> coolant (1)relay
> Mist (1)relay
> doors (1)switch
> Spindle enable (1) relay
> Machine start (1) relay
> E-stop (1)switch
> Toolchanger (2, possible stepper, possible servo, posible encoder).
> Jog wheel (encoder....possibly mouse encoder adaptable but true jog
> wheels index or "click" to represent 1 step of the jog increment)
> Handwheel (for manual style milling from a CNC) possible use of a
> mouse style encoder for this
> Powerfeeds (also for manual milling on a CNC). There exists a very
> cool Knee mill called a Bridgeport R1 C3 which is similar to a BOSS
> but has a Heidenhein control and both a handwheel and levers that act
> as powerfeeds. You simply dial in the feedrate for the levers and
> when you push it in the direction you want, the table moves that way.
> There are two levers. One is on the Quill housing and moves only up
> and down, the other is on the front of the table and moves up and
> down for Y and left/right for X axis travel. Each lever has a button
> on the top which you press for rapid travel over-ride of the feedrate.
> This is a VERY cool machine. The only thing it lacks is actual
> physical feedback (resistance) on the handwheel, but otherwise
> combines great manual features with great CNC features. Not including
> the rapid buttons, this would entail 6 switches somehow rigged or
> built into two levers or joysticks. (unlike joysticks however, you
> cannot move X and Y simultaineously (as it should be for powerfeeds).
>
> Air pressure switch (1) switch. This is dire for machines that use
> air pressure as a counter balance for the spindle. Severe damage can
> result if the spindle drops (actually the whole axis drops).
>
> Spindle speed control (1) DAC
>
> Tachometer (not sure) Camtronics advertises an optical tach for about
> 60 bux. Some older machines use air to drive varispeed pulleys to
> change the spindle speed. That actual activator is electric though.
> (electric switch activates air solenoid to physically reposition
> pulleys) The Bridgeport BOSS works like this. Others use electrically
> operated mechanisms to accomplish the same thing. Both could be
> controlled via two relays if the program could accept tachometer
> feedback to know when to stop. That's more down the electronic wiz
> road then I care to go, but would be an inexpensive alterative to a
> spindle drive or VFD to accomplish constant surface speed without
> standing there changing speeds manually. (Remember, the same tool can
> do a lot of different stuff before you have to change it...some of
> those things require different speeds)
>
> Ok, that seems like a bunch but a kind soul from this board pointed
> me at this...
> http://www.bsof.com/r101prod.htm
> Which should be enough for your relays. Switches could be handled (I
> guess) by an additional LPT or a motion control board with more I/O.
> That bsof.com site has some neat rigs.
> dac could also be handled by a motion card.
>
> If you had enough relays and you wanted to get really trick you could
> also do things like hook up the flashing warning lights that go on
> when you start a cycle...etc.
>
> Although covered in many apps, tool offsets and compensation become
> more important when you have a toolchanger. The program has to know
> what tool is in each position and operate the cycle.
> The toolchanger is perhaps the most complicated of all of this. I
> will get into one and see if I can get back to you on the internal
> workings of it.
> Still, it seems like the hard part has been done. All of this merely
> amounts to a very flexible I/O and some custom macro ability added to
> what is already out there. We're not talking about pre-fab stuff
> here, just the ability for people to wire this switch, or that relay
> into their system and have it do something. Basically the easiest
> part of what the hobbiests already do ( I mean they are making custom
> mounts for their servo's and linear slide tables already, they could
> handle some basic wiring). In reality, you tear apart a CNC and it's
> really a whole bunch of switches (mostly magnetic), but for sure
> there's more than 4 to consider.
>
> Here is an example of an outdated controller (which obviously was
> pulled)
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1703765502
>
> and some machines that could be retrofit candidates...
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1703318626
>
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?
> ViewItem&item=1701057038&r=0&t=0&showTutorial=0&ed=1013482363&indexURL
> =0&rd=1
>
> The two mills I pointed to could probably be well served by the basic
> 3 axis motion control and 4 inputs, although spindle speed control,
> and the handwheel/powerfeed levers would greatly increase their
> usefulness over even their factory new state by providing manual
> control. Especially because many people don't have the space for a
> manual machine and a CNC machine.
> If you keep an eye out on that eBay page (search for CNC) you will
> see a miriad of older machines that could be born again with the
> right control.
>
> Sean
>
>
> -- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > 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?