Messages

4631

Mach4 General Discussion / Re: Was just given an Ethernet Smooth Stepper

« on: May 07, 2018, 01:02:02 AM »

Hi Reinhard,
I bash the Chinese because they make and sell s***t and then don't even bother to help or answer their emails.
If they want to avoid the criticism then they need to support the customers....simple!

You pose an interesting question re NFS and their regard, or lack of, for their Hobby customers. Bryanna, an
NFS employee has stated in a number of posts that  NFS DO value hobby customers.

My own opinion is not so much that they don't value 'us' but they value Industrial and OEM customers that much
more. Given the business imperative I don't blame them, but like you perceive that 'our' input is not reflected
later builds. Notwithstanding that difference of opinion NFS DO respond to their customers, all of them, and they maintain
and host this website for their customers benefit, the Chinese don't.

Warp9 have one full-time employee whom is dedicated to their forum for their customers. You show me a website
maintained/hosted by a Chinese manufacturer for their CNC controller.

I would agree that my comment does cast ALL Chinese people as ripoffs and you are quite correct to call me on it,
I should not do it.

it or us for buying it?

You may have noted I also took a pretty broad shot at all the idiots who buy cheap and nasty and then whinge that is doesn't
work. I have from time to time done the same, that is, bought cheap and nasty Chinese only to be disappointed.
That makes me  a bloody idiot also!

Craig

4632

General Mach Discussion / Re: MACH3 spindle behaviour

« on: May 06, 2018, 06:45:46 PM »

Hi,
my experience which I doubt is unique was that I spent a lot of time getting speed just right,
FWD/REV etc only to find that I don't really need it.

Do you have any LH mill tools or drills for instance? When using my high speed spindle for routing (24000 rpm)
I just set to max speed and leave it there. If I could make it go faster I would.

Occasionally when doing aluminium I'll drop it to 15000 rpm, give or take...its not that critical.

When I'm doing steel or stainless I use my high torque spindle. Its based on a kick arse AC servo. I've got great
control over it but again I don't need it most of the time, within 10-20% is good enough.

My recommendation is don't get to hung up on spindle speed unless you have to for some reason. You may find
as you spend more time making chips that other matters become more important. In my case its coolant
for steel and stainless, much more important than spindle speed.

Craig

4633

General Mach Discussion / Re: Newbie Question - Redcam CNC won't run with Mach 3

« on: May 06, 2018, 04:36:06 PM »

Hi,
kool, we'll work through the questions one by one.

Need to determine if the parallel port driver is working well, run DriverTest.exe

Craig

4634

Mach4 General Discussion / Re: Spindle at Speed

« on: May 06, 2018, 10:45:04 AM »

Hi,
Machs developers made available a sophisticated spindle index sensing suite including a very accurate speed measurement and live DRO reporting with delays until up to a percentage of
commanded speed. Is there a reason that you didn't use the facility that was provided?

Craig

4635

General Mach Discussion / Re: MACH3 spindle behaviour

« on: May 06, 2018, 10:37:38 AM »

Hi,
many inductive sensors have a low bandwidth, 50-100 Hz and such sensors are not adequate for index signaling. Hall sensors are appropriate.

Is there a particular reason you need really accurate speed? In most cases you just set the speed, often as fast as it will go, and leave it there. Who really
cares what speed it is?

Craig

4636

Mach4 General Discussion / Re: Spindle at Speed

« on: May 06, 2018, 10:24:44 AM »

Hi,

Like hakan said, it's a bug/or unfinished software.

Rubbish. The Signal is defined its Action is not....you the machine integrator have to decide what action is correct and code it accordingly. Mach4 IS NOT LIKE Mach3, its not
plug and play.

Craig

4637

Mach4 General Discussion / Re: Was just given an Ethernet Smooth Stepper

« on: May 06, 2018, 10:02:12 AM »

Hi,
the only thing Chinese I buy is chop suey!

It nots that bad actually, I like Delta servos and VFDs for instance but they produce some absolute s*********t ones as well, the price usually gives them away. We, or at
least some of us, buy them and whinge when they don't work. Who's being stupid here....the Chinese for making and selling it or us for buying it? Remember the Chinese
have our money already so they're not that silly....and do they care whether we're happy on not? No.

Craig

4638

Mach4 General Discussion / Re: Spindle at Speed

« on: May 06, 2018, 09:17:47 AM »

Hi,
I was heavily involved in a conversation about exactly this matter some time ago:

http://www.machsupport.com/forum/index.php/topic,35694.0.html

Craig

4639

Mach4 General Discussion / Re: Was just given an Ethernet Smooth Stepper

« on: May 06, 2018, 02:35:26 AM »

Hi,

I did some work for a fellow to get his new CNC up and running and was given an Ethernet Smooth Stepper in thanks.

You can tell this rooster I'll help....electronics...CNC.....mechanical....babysitting...anything!. I need a set of 400W AC servos...LOL

4640

General Mach Discussion / Re: Setting up limit switches, Mach3

« on: May 06, 2018, 01:46:20 AM »

Hi,
some background to the choices....

Industrial machines have both limit switches AND home switches.

Industrial machines usually have powerful servos through reduction gears driving the axes and have a great deal of thrust and momentum. It is vital that limit switches
protect the machine and operator in the event of an overlimit excursion.

In Mach3 its common that a limit event will cause Mach to issue an Estop command and therefore stop all motion. This relies on the computer to recognize a signal and shut the machine
down. An industrial machine cannot rely on a computer, its just too dangerous. Consequently the limit switches are hooked into the power supply. If a limit event occurs the main contactor
drops out and the machine de-powers....no ifs....no buts. This will often result in damage to the workpiece and will certainly require considerable time before the machine can be reset and put back
in service. For an industrial machine to hit its limits is a bad bad thing, the limits  are there as a last resort and probably legally mandated that they work in an absolutely certain way and so you try
to avoid overlimit excursions by all means possible.

There are those on the forum whom advocate that our hobby machines should operate the same way. I did not bother with my mill and lots of other hobbyists ignore that advice as I have. I suppose
it depends on your machine, if you had an axis powered by a hydraulic ram you'd certainly have to think about it!

One means of preventing overlimit events is 'Soft Limits' It means essentially that Mach keeps track of where the spindle is and if you create a move one meter to the right say, and it knows the
X boundary is only 500mm in that direction it will not do the move. This relies on Mach being able to keep track of the machines position. Mach does a very good job of this  except under fault
conditions. When you first start Mach though it has no idea where the machine is, you have to tell it or 'Reference' it. This is where home switches come into play. An axis, lets say X, will drive
at a slow (you nominate how fast) speed towards the X axis home switch. When the switch activates it backs up until the switch deactivates again and Mach 'declares...we are at X 0' and sets the
machine coordinates of the X axis to zero. It will then home the next axis in your nominated home order. Once all three axes have completed homing the machine is now at 0,0,0.

The Home Direction, Home Order, Home Speed are part of the data you will be required to populate the Home/Limits page. You will also tell Mach where the boundaries of your machine are relative
to the 0,0,0 point. They are known as the Soft Limits. If for instance you had you X home switch 100 mm in from the right hand most end of the X axis and the axis had 1000mm of travel the the soft
limits would be -900mm and 100mm.

Because Mach relies on the numbers you have supplied to protect both the machine and you its important that the home switches reliably and very repeatibly  signal the 0,0,0 location. I use quality
Honeywell Roller Plunger microswitches with activation ramps which allow good repeatability. I get 0.02mm which I am happy with. I can for instance be doing a job and stop it part way through, turn the
machine off and come back the next day, re-reference my machine and start from where I left off yesterday within 0.02mm without having to reset or re-measure anything.

I operated my mill without home switches for about 9 months and had a few crashes, especially as I was learning. Then I got around to fitting home switches and I've had one crash in the four years
since, and that was because I was doing something oddball and forgot to home the machine before I hit Cycle Start......dummy!!! All in all good home switches have done more to improve my mill
than any other modification.  I highly recommend you fit good home switches.

You may have noted that the home switch DOES NOT HAVE TO BE at one end, its common but not actually required. Sometimes its much easier to mount a switch somewhere inside the ends. Limit
switches on the other hand have to be mounted so that they operate and the ends of travel. That brings us to the next point. In the early days of Mach when everyone use a single parallel port
which has only five inputs it was necessary to economise on inputs and try to combine both home and limit switches. Many people still do but I think its a mistake. If you use one or more of your limit
switches as a home switch as well when homing Mach treats it as a home switch. If the machine cocks up it will sail past the home switch....remember while homing it ignores limits and you crash. Whereas if
you have separate home and limit switches then Mach will ALLWAYS treat a limit switch as a limit event and Estop, even and especially when homing. If you are going to have a cock-up whats the bet
it will happen when you are trying to sneak up on a switch, particularly if that switch is right at the end, a few mm more and CRASH!!!

I think that your controller has plenty of inputs and so you can arrange homes an limits for best performance rather than be limited by available inputs. I would have three separate home switches,
each with its own input pin. All the normally closed contacts of your limit switches (six of them) can ALL be connected in series to one pin for limit protection. You probably have enough inputs to
have each limit switch on its own pin, a modest advantage only.

A few ideas to think about!

Craig