[HawkJET]

THANKS Sam!

YES! I agree! Thanks Sam.

[chester88]

Hawkjet:

I wonder if you could list the 5 most important things you wanted to know that you could not easily find out. Maybe we could improve this.

Chris M

[HawkJET]

I wonder if you could list the 5 most important things you wanted to know that you could not easily find out.

Thanks Chris. I don't know if I can remember everything at this point since I have moved past it by now, but I'll give it a shot.

... Okay, I remember being quite confused by all the jargon. It would be great to have a glossary or something (there may already be one but it isn't in the "storefront" if ya know what I mean). It could include an overview of the entire system with explanations of HAL, GIT, Kubuntu, Xubuntu, and why I care (or not) about them (or the other acronyms I don't remember)....

I could never get an explanation of how to have EMC2 open in a maximized window. What I did get is some links to discussions about it being a bug or something and how different versions are different (this leads me to wonder if it is really a mature package).

It would be great to know more about what programs have an effect on the speed/reliability of EMC2 operation. After an hour or so of reading, I stumbled upon something that indicated that the ability for the computer to turn itself off was disabled for these reasons. But it's crazy to me that a lot of other useless stuff seemed to be loaded on boot up that appear to use resources for no real reason... it just seems inconsistent and kind of penny wise and pound foolish (this also leads me to wonder if it is really a mature package).

For some reason the latency test said I can get 33 kHz in EMC2 but Mach3 indicates 100 kHz will work fine. This pretty much tells me there is no advantage to EMC2 since speed and stability were supposedly its selling points.

Oh yeah, some explanation of IRC and mailing lists and how to use them. These are examples (at least to me) as how finding information and help is off the beaten path. Until a few days ago I didn't even know how to spell IRC, let alone what it stands for or how to use it (I still don't because I got some arcane error message when I tried).


That's all I remember right off the bat. I hope that helps.

Cris

[MrWild]

For some reason the latency test said I can get 33 kHz in EMC2 but Mach3 indicates 100 kHz will work fine. This pretty much tells me there is no advantage to EMC2 since speed and stability were supposedly its selling points.

What computer and vid card are you using? On board video has an affect on latency. I'm running Dell Dimension with 2.0 ghz processor, 1gb RAM and a 32mb Invidia video card and my latency is well below 9000. 180ipm with 1/2-10 lead screws, steppers, and a G540. While it smokes in rapids, I need to slow it down to 45ipm for cuts due to stepper power losses at higher rpm. I'm trying to learn all i can with the JGRO, and then plan on finishing a MESA 5i20 build with servos and analog drives. Baby steps.

[dond3]

Just a couple of comments about EMC2. When you run EMC2, you are using a patched kernel. This kernel supports a Real Time Operating System (RTOS). A lot of the bells and whistles have been removed to improve performance. You have things like Firefox so you can update online. You can download the update on another computer and burn the files on a CD, DVD or flash drive and install from there.

From what I have read, the automatic "turn off" ability doesn't work because of the stripped down nature of the Ubuntu supplied Operating System. Same with the ability to start "full Screen". I could be wrong.

There is a ton of information on the LinuxCNC wiki. It's just spread out all over the place. You just have to follow the links.

There is a good mailing list where some of the developers hang out. If you are interested, I will hunt down the URL.

I hope this helps.

Don

[HawkJET]

Just a couple of comments about EMC2.

To be sure this wasn't missed from an earlier post, I am now using Mach3. My recent posts are in response to questions as to what my issues (with EMC2) were and the posters are looking at what could be done to help future EMC2 newbies.

There is a ton of information on the LinuxCNC wiki. It's just spread out all over the place. You just have to follow the links.

This illustrates part of the reason I am now using Mach3 - the information is spread out all over the place. It was taking forever to find some basic information so I switched over.

There is a good mailing list where some of the developers hang out. If you are interested, I will hunt down the URL.

Thanks Don, I already have it somewhere.

[cyclestart]

Same with the ability to start "full Screen". I could be wrong.

afaik that has to do with some some quirk in the Gnome desktop and is not kernel related. No biggie although some users have found ways around that behavior. The fixes mentioned may or may not still be valid.

I can empathize somewhat with HawkJet but will add the documentation is much, MUCH better than it was when I started with emc (yes emc, not emc2). The software is constantly improving also. Thank you to everyone who contributes to this project.

[JoeBean]

The problem I ran into was that even with a serious effort (at least I thought it was), I still had very basic questions that would have me seem as though there was no serious effort.

There is still something I don't understand. When I look at Art and Mach3, there were a lot of people that offered help with tutorials and manuals when Art was busy writing code. These people were also volunteers and were enthusiastic and really wanted to contribute. And this was years ago when Art was working on Mach2. What is so different in the EMC community?

I may not have worded it correctly above, but yes, it basically has to do with what you'd call the "mentality". People in the OSS communities are just as susceptible to groupthink as any other group, of course, and unfortunately many/most OSS projects perpetuate the idea that users are lusers, and headaches. Thus people tend to assume that with every person to come along. RTFM (Read The [we'll pretend it's Fine] Manual) is a common retort.

Interestingly, some projects actively adopt a different attitude, starting with the project leads and trickling down to the other developers. FreeBSD is one outstanding example in that, IMO. Very user-friendly. Ubuntu seems to have much the same spirit as well. EMC, unfortunately, isn't so much like that.

[HawkJET]

EMC, unfortunately, isn't so much like that.

Great explanation Joe! I can see that I had expected something different. You seem to have a great perspective on the overall context (and a very mature attitude). I guess if I knew more about what I was in for, I could have approached things differently and gotten different results.

This community here seems to have a helpful attitude. Maybe this thread (along with those like chester88) can help make it a little easier for newbies tthat follow.

[JoeBean]

... Okay, I remember being quite confused by all the jargon. It would be great to have a glossary or something (there may already be one but it isn't in the "storefront" if ya know what I mean). It could include an overview of the entire system with explanations of HAL, GIT, Kubuntu, Xubuntu, and why I care (or not) about them (or the other acronyms I don't remember)....

These are largely Linux related and/or Ubuntu-specific terms. That's likely why there's no explanation - it's viewed as a waste of effort when people are expected to be familiar with these things. I agree that it's not user-friendly. It's often suggested that Linux/OSS suffers from a gloat of programmers and a drought of technical writers. Unfortunately that's often because what a tech writer would view as critical, such as a useful manual, is shrugged off as unnecessary.

I could never get an explanation of how to have EMC2 open in a maximized window. What I did get is some links to discussions about it being a bug or something and how different versions are different (this leads me to wonder if it is really a mature package).

This is a bug in gnome. Like so many other OSS projects with poorly defined leadership, it seems that they'd rather b*tch about it, blame others, and then spend time writing 400 bloated additions or completely rewriting the codebase rather than address the problem. Some supposed workarounds:
http://www.extremetech.com/article2/...2140149,00.asp
http://wiki.ubuntuforums.org/showthread.php?t=1455308

It would be great to know more about what programs have an effect on the speed/reliability of EMC2 operation. After an hour or so of reading, I stumbled upon something that indicated that the ability for the computer to turn itself off was disabled for these reasons. But it's crazy to me that a lot of other useless stuff seemed to be loaded on boot up that appear to use resources for no real reason... it just seems inconsistent and kind of penny wise and pound foolish (this also leads me to wonder if it is really a mature package).

This is another generic *nix issue that I guess they figured everybody ought to have RTFM'd and figured out themselves.
From the command line/terminal "ps auxw" should give you a list of all running processes with the CPU usage %. "top" will give you this info as well, albeit it can be a PITA to see everything. moded versions exist that will,like atop, but you need to install them.

When you find a process you think you can do without you can type:
"kill -9 {processid}" where {processid} is the # of the process listed in the command before, such as 429. If you don't know they PID but you know the name you can also type:
"pidof {ProcessName}"
To get the PID. Yes, complicated. There's a graphical program called QPS that you can download and use to do this though. I don't believe it's installed by default.

For some reason the latency test said I can get 33 kHz in EMC2 but Mach3 indicates 100 kHz will work fine. This pretty much tells me there is no advantage to EMC2 since speed and stability were supposedly its selling points.

To be sure EMC does have a number of advantages. For instance, Mach3 still can't control hexapods or robot arms. It just requires a lot of knowledge to begin with.

If you're a reader you'd get a kick out of the Unix Haters Handbook. Very apropos. And you'll probably learn a fair bit about how *nix works and why it does things they way it does.

[HawkJET]

If you're a reader you'd get a kick out of the Unix Haters Handbook. Very apropos. And you'll probably learn a fair bit about how *nix works and why it does things they way it does.

I just read a few pages and it cracked me up!

I really appreciate your wisdom Joe! You and others have helped me get to the point that, if I switched back to EMC2, I could probably get it to work fairly quickly now.

But now that I know some of its quirks, I find that it doesn't appear to fulfill my needs as well as Mach3 seems to. Basically, it looks like I first have to learn more about Linux to get past the minor bugs, but what I want to do is get my CNC running. EMC2 looks like the longer path.

[samco]

Sorry to hear about your emc2 experiences.

Can I ask what mach is doing for you that emc cannot? (other than the 'finding info')

thanks
sam

[HawkJET]

Can I ask what mach is doing for you that emc cannot? (other than the 'finding info')

1. For some reason, Mach3 says I can get 100kHz whereas EMC2 says 33kHz. This surprises me since one of the main reasons I went to EMC2 to begin with was because I thought it would be faster and more stable.

2. I can easily configure everything to boot up with Mach3 running and its window maximized. Plus, when I shut down, the computer will turn itself off.

3. The display screens are easily created and/or customized with Mach's Screen4 program. Scripts and macros are easily done. A video camera can be easily used to find zero.

I'm sure items 2 and 3 can also be done in EMC2, but Mach3 is VERY user friendly, whereas my experience with EMC2 is that it's user hostile. Basically, the path from "nothing" to "CNC working" (all tricked out) is much shorter.

4. Whether or not it's actually true, my experience is that with Mach3 it is easier to get support, and quickly.

5. Mach3 will work with SmoothStepper if I need even more speed (although SmoothStepper is no panacea).

That's what comes to mind quickly.

[samco]

1. For some reason, Mach3 says I can get 100kHz whereas EMC2 says 33kHz. This surprises me since one of the main reasons I went to EMC2 to begin with was because I thought it would be faster and more stable.

I have never seen anything higher than about 50khz personally from emc - others have gotten higher. I have never used mach but have only heard from converts. They say that emc outputs a much better pulse train. If I where to need anything more than that - mesa or pico systems have hardware step genterator hardware that will go into the mhz. The mesa hardware can be had for under $100 (48 i/o) that runs off a printer port - or $200 pci (72 i/o). (no usb interfaces - read below.) Have you tried running mach at 100khz?

2. I can easily configure everything to boot up with Mach3 running and its window maximized. Plus, when I shut down, the computer will turn itself off.

I don't have a comment for the windows maximized issue. Shut down issue has to do with the rtai kernel. For the kernel to work with the most computer hardware - acpi (power management) is disabled. This makes it so linux cannot shut off the computer by itself. The newer kernel for the latest version of ubuntu may have this enabled. time will tell.

3. The display screens are easily created and/or customized with Mach's Screen4 program. Scripts and macros are easily done. A video camera can be easily used to find zero.

This comes up quite often. The answer is - no one has made a screen editor yet. Anyone could if they wanted to. There is actually a german group that is creating a gui (I think it is called moca) that you can build screens with a xml file. I don't know how far along it is. So maybe in the future. If I need any extra buttons or such - I just build a pyvcp pannel with the extra buttons and indicators. like this - (right side of the axis gui) http://www.linuxcnc.org/docs/2.4/html/gs2_panel.png

I'm sure items 2 and 3 can also be done in EMC2, but Mach3 is VERY user friendly, whereas my experience with EMC2 is that it's user hostile. Basically, the path from "nothing" to "CNC working" (all tricked out) is much shorter.

cannot comment on this.

4. Whether or not it's actually true, my experience is that with Mach3 it is easier to get support, and quickly.

I have always had my questions answered very quickly - most of the time as I am taking with other users or developers on irc within minutes.

5. Mach3 will work with SmoothStepper if I need even more speed (although SmoothStepper is no panacea).

Emc will probably never use usb. emc want to be in control - true closed loop. even steppers are closed loop - just the loop is internal to EMC. USB isn't realtime enough. Smooth stepper moves the motion outside of mach. Anything that moves motion outside of emc - isn't a good match. In my opinion - the hardware options for emc are much more flexable. You can do open loop, closed loop, steppers, servos all in the same machine.

That's what comes to mind quickly.

[HawkJET]

They say that emc outputs a much better pulse train... Have you tried running mach at 100khz?

Yeah, I've heard the pulse train is better too. I haven't run the motors yet so I am not confident in the 100kHz either.

I have always had my questions answered very quickly - most of the time as I am taking with other users or developers on irc within minutes.

That's the thing... IRC, I've never used it. When I tried, I got an error message I didn't understand. The place to get answers is off the beaten path. Everything is nonstandard (or at least it seem like that to me). It seems like there is some sense of pride in being "different". As if it is more important to be different than it is to be useful... frustrating....

Plus, a lot of the answers/help I have received has just gone over my head. I am REALLY ignorant in regard to Linux/EMC... REALLY ignorant. You have no idea how basic some of your answers need to be so I can follow them. I don't even know most of the basics that you take for granted everyone knows. As a result, I probably ask a lot of stupid questions.

It is similar to telling me that A^2 + B^2 = C^2, but then I am supposed to know what A, B, and C are... BUT I DON'T! I'm not stupid, just ignorant.

In my opinion - the hardware options for emc are much more flexable.

I don't doubt that. I am clear there are advantages to EMC. I just found too many frustrations.

[Dropout]

Currently I am helping someone with even less programming nounce than me write a custom kinematics module to automatically compensate for kerf angle on a waterjet.

Maybe this ought to be in another thread, but what all was involved in running a waterjet with emc2?

Is it using a 4th axis for the kerf compensation?

How did you handle the deceleration and acceleration for the corners?

[MrWild]

ohhhhhhhh, One question on speeds. Have you read the emc2 manual at all? Not a snide question at all so don't take it as one. If you are just playing with EMC2 and haven't wired your steppers or used the config wizard except to get a feel, I'm wondering if you used the latency test yet.

At the bottom of the first page in the config wizard, the one where you can name the machine at the top, there is a button for "test latency" (or something like that, I'm new too). Once you've an idea what your computer's latency is, you can fill in the base us period. Here's the thing. UNLESS YOU SET A DIFFERENT AMOUNT, EMC2 WILL USE THE GENERIC BASE PERIOD. It isn't that EMC2 won't go faster, it's that the set up when installed, is set at a speed even slow PIII machines will handle. I bet Mach has a pie in the sky new install speed that is just plain unrealistic without a new computer and guess what? The new super fast computers don't have parallel ports.

I doubt it isn't what Mach can actually do in the real world, it's how the program loads when new, but MOST Mach users need to set it MUCH slower and many don't go over 45,000.

ADDENDUM

I just checked my JGRO Dell Dimension 240 PIV 2.0ghz, and see my speed is 50000 hz. I've had it up to 70000 hz and the axis tested fine, but I slowed it down because I learned long ago everything doesn't need to be lead footed to the extreme. Even with 50000 hz, I can still rapid at 180ipm using 1/2-10 lead screws and a G540. I rapid at 90 though, because after all this is just a JGRO. Just how fast do water jets cut? I honestly don't think Mach will out shoot EMC2 when it comes to speed, just because Windows adds it's own glitchyness to the stew.

[HawkJET]

Here's the thing. UNLESS YOU SET A DIFFERENT AMOUNT, EMC2 WILL USE THE GENERIC BASE PERIOD. It isn't that EMC2 won't go faster, it's that the set up when installed

I did the latency test and replaced the default value with the result of that test.

I doubt it isn't what Mach can actually do in the real world, it's how the program loads when new, but MOST Mach users need to set it MUCH slower and many don't go over 45,000.

Mach3 loads with a default of 25kHz. I changed it to 100 and did a test (Mach3's equivalent to EMC2's latency).

I honestly don't think Mach will out shoot EMC2 when it comes to speed, just because Windows adds it's own glitchyness to the stew.

I am with you here. I don't know what was going on and I was quite surprised.

[lerman]

It seems that many of your complaints are related to an ignorance of linux. That isn't EMCs fault.

How easy do you think Mach would be to use if you had never seen windows before?

What is good for me (or you) isn't necessarily good for everyone.

Ken

[dertsap]

I honestly don't think Mach will out shoot EMC2 when it comes to speed, just because Windows adds it's own glitchyness to the stew.

i disagree , I used emc up to about 1 1/2 - 2 yrs ago , and when I built my last cnc emc couldn't push my motors anywhere near as fast as mach , I've had guys slam me and under assumption tell me that I didn't do things right . I knew exactly what i was doing and did a lot of reading and research , but the bottom line is the speeds that I was easily able to get thru mach would crash and freeze emc and the operating system .