Yes, you do need a special PC. This means a PC you use for Linux CNC and
not the one already on your desk.
Why would I want to run them from my main desktop machine? My CNC
machines are out in the workshop where they belong. They are big, dirty,
smelly and noisy. I don't want them in them same room with me when I'm
doing other stuff. If I really want to monitor what they are doing VNC
does a good job. I personally don't bother because I very seldom run
multi-hour programs.
Linux is comes with the normal productivity tools so there is no reason
why you can't run them on your LinuxCNC computer. For example my mill
and plasma both have CAD, CAM, browser etc. Basically all of the
functionality I need to go from thoughts in my head to finished parts.
If I wanted to I could build a desktop PC with full office functionality
and use it to run a desktop CNC router as well. Of course to fit on a
desktop that router would be too small and light for nearly all of the
work I do so it would just sit gathering dust. Speaking of dust, a
machine that spews wood dust into the work space is a very bad idea.
I've been exposed to wood dust in the work place for many years and am
now paying the price. Yes, I could add extraction to the router but that
adds to the noise and sucks the heat outside. My nice quiet warm office
now becomes a noisy freezer.
Again think of the normal ink-jet
printer. Do you connect it to a special "printer PC" that is only used to
drive inkjet printers? No. In most cases, the inkjet (or laser)
printer is just on WiFi and can print from any iPhone of PC that is also on
the same WiFi.
What market are you aiming at? Machine shops want a machine that they
can start up in the morning and just keeps spitting out parts until it
runs out of stock. They /really /don't want just anyone being able to
send files to it and mess with it. Nearly all machining centers have
network connectivity so loading in a new job is just a case of pulling
the files from a shared drive. The operator looks at his job sheet, sets
the machine up with the appropriate fixtures, cutters etc then loads the
code from a local or shared drive and presses go. There's no point being
able to push the programs to the machine if you still have to be there
in person to set it up.
A hobbyist just starting out may want something they can 'just print' to
but realistically that is only practical for something like a laser or
maybe very basic work on a small format desktop router. For anything
else you are never going to get to something like a printer where you
conceive a design and the machine cuts it out with next to no user
input. There are just too many variables. To print a page pretty much
the only options you have are orientation, page size and maybe selecting
color or black and white. With machining there are millions of possible
variations of what you can do. Are you starting from a blank, raw stock
or maybe a pre-machined part? What cutters are you using? What outlines
do you actually want to machine? What fixturing do you need? CAM has
improved a lot over the years and will get better but if you really want
a 'feed raw stock in one end and any part you want comes out the other'
the only way you'll get it is with 3D printing. 3D printing has a very
long way to go before it becomes practical for general production parts.
This is a common thing. Users typically get used to what they have and ask
for only tiny, incremental changes.
Over time, tiny incremental changes have a big effect. Lets' face it the
only difference between humans and fish is a series of incremental
changes over time. CNC machines have been around for quite some time and
have ended up looking as they do now for very good reasons.
That said, disruptive change is really hard to do as it takes a change of
mind-set. You have to kick the problem around for a long time before you
see a completely different solution.
You also need to have a deep understanding of the problem. Look at the
thousands of startups out there that have 'revolutionary' ideas that
fail spectacularly because they didn't really understand the problem.
How much experience do you have with operating CNC machines?
In any case, that CNC machine does not have or need a PC computer with
modern GUI interface connected directly to run it. That's why I
started this discussion. X-windows is waste of resources, it's another
thing that needs to be maintained and updated in some instances. Too
many things to go bad in what's supposed to be a relatively simple
embedded system.
Look at any modern machining center. They have a honking big display
that lets you know at a glance if everything is working correctly and
lets you set the machine up quickly and efficiently. I've used machines
with 2 line LCD displays and the menus are painful to use. The only time
they work is if you are doing really simple stuff that needs little
setup. For instance if you're routing signs out of sheet materials. Your
machine has pretty much one setup and you just feed different outlines
to it. This is pretty much the only case where your 'printer' approach
really works in real life. Early cnc machines started of with minimal
displays and as they have become more sophisticated the displays have
become bigger and easier to use. If those early displays were such a
good idea why are they almost never seen on modern machines?
When I designed the E-Leadscrew Electronic Lead Screw controller the feedback
from the non-CNC people was that they wanted something more than just
electronic gearing (now commonly also called an ELS) but not something as
extensive as full CNC.
I am afraid I never really understood that mindset. ELS has some
advantages over manual but where going from full manual to ELS is a step
forward, going from ELS to CNC is a leap forward in capability, for not
much difference in cost. You already have the drivers, motors,
mechanical parts etc. The only real difference in hardware is the
controller. Is CNC harder to learn than ELS? Yes, but not that much. I
mainly make one-off parts and after switching from manual to CNC many
years ago there is no way on earth I'd go back. If I'm making a very
simple part I use the hand wheels and have a DRO on steroids. Maybe I
need to drill a hole at a specific position. Type in G0 x.. y.. then
grab the handwheel to drill the hole. How about rounding off the end of
a flat bar? I could do a rough job with a grinder but a bit of manual
positioning and one line of g-code gives me a perfectly rounded end in
less time. The basics of g-code are pretty simple. You only need to
learn half a dozen commands for basic mixed manual/cnc work as I just
described. For anything more complex CAM does a great job and you don't
even need to know anything about g-code.
Les
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
