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Topics - gumbyrulesyou

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1
General Mach Discussion / MPG jog rate - Unresolved or not?
« on: August 26, 2015, 01:42:01 PM »
This issue was posted...maybe in 2008 I think? Was this ever addressed or resolved? The thread digressed in to trade show scheduling rather rapidly...

I just dusted off my mill after a couple of years, downloaded the latest MACH3 and started to test to make sure everything was OK.  I have an MPG pendent that I built which has two rotary switches. These go into a keyboard emulator (IPAC) then into KeyGrabber (utility software) to pass the appropriate keystrokes to MACH3.  I modified the 1024 standard screen set as follows:

Note:  I'm set to Imperial units

MPG X axis    <ALT X>    OEM Code 259
MPG Y axis    <ALT Y>    OEM Code 260
MPG Z axis    <ALT Z>    OEM Code 261
MPG OFF       <ALT T>    OEM Code 276 (Which I use to turn MPG on/off)

All of the above work, so the scheme is fine
Now the problem is with the rosolution:
.01           <ALT U>    OEM Code 267
.001          <ALT V>    OEM Code 268
.0001         <ALT W>    OEM Code 269

The above values were taken from the standard settings (or at least how I interpeted them) from MACH3 default configuration.

The MPG is calibrated to 4 clicks per detent

The problem:
Regardless of the setting I choose for the resolution, I seem to get about .0014" movement of an axis for each click of the MPG.  I also have a joystick set up and I get the same result from the joystick on step mode (actually, the joystick sometimes steps and sometime not, the MPG always steps.  When the joystick does step it's the same about .0014".

I have not been auditing the group for a while, so if this was addressed before, I appologize.

Any ideas about what's going on and how to fix the problem would be appreciated.

Jeff


Andy

2
So I have an MPG going in to a USB Smoothstepper in Mach3, and everything is grand, more or less. Electrically, all functions are working - - MPG jogging, X/Y/Z/A/OFF select, and when I TAB out to the MPG mode window, selecting the .001 / .01 / .1 changes the 'Cycle Jog Step' number to what it's supposed to be, and the encoder isn't dropping steps or anything funny. It's a differential drive going in to Smoothstepper's special inputs and it's clean as a whistle.

Problem is..

Changing that scale dial does nothing to change the MPG resolution. I once had this working on an AJAX-CNC system and it worked pretty much as I thought it should, and I THINK I had it once working right on Smoothstepper, but right now, it's doing squat. Also, the step distance per tick seems to be rather arbitrary. My current count/unit is at 4, which is technically "right" for my MPG.

I have the MPG mode set to Step/Velocity. I can set it to MultiStep and it sort of works, but it shakes the crap out of the machine.

Now, I'd be happy to change the BRAIN associated with it to adjust the COUNTS/UNIT for the MPG in question, but I can't find a code for that.  I know this question has been floated around the forums before, but never really answered that well. Is there an OEM code to change this? There are codes to change the motor pulses per unit, this one seems like it should have a code too?

I'm running Mach 3.043.062 and USB Smoothstepper V17FD

I'm running Mach 062 on the recommendation of Warp9TD - http://www.warp9td.com/index.php/sw/software-mach#MachThree
Apparently it's more stable?

Anybody have any thoughts?

Thanks,
Andy

Andy

3
Hello,

So I'm wondering what other people's thoughts are on the dspMC/IP system. I currently have an Ajax / Centroid system in my CNC router, and I sort of regret putting it in there, mostly because it's badly supported, look-ahead and constant contouring don't seem to really work right, it's a horrible slow manual process to tune the PID loops, and forget using the auto-tune. In fact, I think I've been running my servos completely out of whack for 2 years now. You have to shut down mach AND the machine and restart the CNC and Mach just to TRY your PID settings. Totally convenient. Just like my Apple II/e. I know they're short handed there, but it's really just been a nightmare. They tell me to buy their Centroid software, but punching in all those unlock codes to even attempt to get autotune going in the Centroid software always ends in getting locked out .... Do I really want to give them another thousand bucks to have a system that still runs like crap? I'm  not really sure. The reason I sort of like the idea of the dspMC/IP is because it runs in MACH and in CNC Linux / EMC and probably some of DSps software too. Is it better supported? Can I do auto-tune ( I have 1KW AC servos with +/- 10V control) Is it stable? Does it have analog spindle control?  What about my MPG - Currently putting out differential quadrature, should work, right? My servos output differential quadrature too. Do I have to restart to try new PID settings? It homes to Index pulses, right? And the MPG connects to the unit directly, right?

What are people's thoughts? I currently have a machine that works and is making money, but isn't without it's fairly major problems, most of which I attribute to the Ajax/Centroid brain in the cabinet.

4
Works in progress / Any screens that DON'T use bitmaps?!@!?
« on: February 25, 2010, 01:50:41 PM »
Are there ANY screens out there that don't use bitmaps? I know I'm free to make my own, and I'll do it, but I don't want to if they already exist.  I personally find that most of the screens out there are hard to read and are all go overboard with drop-shadow, emboss, gradients and silly fonts, etc, all of which has got to be sucking up RAM and CPU resources. Does such a thing exist?

Andy

5
OK - I'm having a little trouble with these routines, particularly the "Destroy Probe" setting, which is activated by showing "machine coordinates" and attempting a "Set Tool Length" probe. Somehow, the behavior changes if the DRO is set either to machine or work coordinates. In machine mode, the tool goes down, touches the setter, pauses, then goes down another inch or so, ignoring the probe and smashing it....except in my case, because I was using a wooden dowel and had my hand on the E-stop.  Other times it probes UP. yes, UP. I touch the setter, it pauses, then does an upwards retract of 0.1 or whatever. Then there's a whole thing with the tool setter height, work offset, etc. Seems pretty complicated, which is where I see some numbers getting swapped around. I'm not going to go in to the button script and rip it up just yet, but for this project, I just want to keep the setter in one place, fixtured to the machine. As long as the offsets of the tools are all correct in respect to each other, and you load one tool and set it's length right, and zero it off the part, then for every other tool you load and probe, it shouldn't matter WHAT the sensor height is, or what the current work coordinate is.  I dunno. I don't get it, except that I don't trust the machine and the setter, and I don't really want to put the setter on the work, since, well then it's not fixed, and what if I set a zero to the material top then carve it all away. I know I should set it to the bottom, but sometimes it just makes sense.  I just need a tool setter routine that I can jog over to the setter position, change the tool, and press "GO" and it plops a number in to the tool table. After all, when I measure with a height gauge on a granite plate, I don't have any reference to the thickness of the TTS tool holder measuring block, or the workpiece zero or any of that, it's just a Z height offset for the tool, and as long as that number is 1.000 different for a tool that's 1" longer, that's all that matters.  Can somebody let me in on whatever secret there is?

Sorry... i'm just really frustrated right now.

Andy

6
SmoothStepper USB / Smoothstepper disconnect safety concerns
« on: December 09, 2008, 03:12:30 PM »
 :D :D

So I tried to report the fact that a smoothstepper will continue to output a pulse train on the charge pump even in the event of an error in Mach...even in the event of a serious system crash, even in the event that I tear the power cord from the computer. Not only that, it will also continue to jog the machine into oblivion if you happen to be jogging when this happens - Power failure, cord ripped out, the extremely unlikely scenario of windows crashing, etc.

I reported this on the Warp9 forum, and all I get is flack.

As you can see, my machine isn't a sherline with stepper motors scavenged out of floppy drives. If I had not set up the limit switches directly in to the servo amp, which by the way folks, don't EVER forget to do this if you can, but if I had not, it would have slammed 1KW/3KW peak of power in to pure bashing, crushing excitement.

With a working charge pump, this would never have happened.  If I had powered the smoothstepper from the PC, true, in the event of a power failure, this would never have happened either. but then again, with all the other boards, MPGs, analog spindle controls, etc, I have to use an external 5V supply for them all, so no smartie pants telling me that USB power is the solution to my problem.

My system is set up seriously. All my amps have and use "Servo Enable" inputs from one line out of Mach. They have logic and motor power input. Logic is always on. On top of servo enable, the motor power input wires, all three phases, go through a contactor on yet another enable line.  The spindle has a contactor AND a VFD, each on their own I/O lines, and all of this goes through my E-stops AND charge pump enable.  The servo fault lines and spindle fault lines all go in to an external e-stop input on the PLC. This is a big, dangerous machine, and I can't afford to drop $10K on a new Fagor controller.



7
General Mach Discussion / A definitive answer on dual processors...
« on: October 08, 2008, 01:03:33 PM »
A definitive answer on dual processors...

I'd like to know the following... this would probably be a question directly for Art. I looked around on the forum and haven't found much on this.


IF I have a dual processor system, IS there a process, specifically the pulsing engine or whatever, that I can select, and give high priority and affinity to one processor, so as to avoid hiccups when I do something rash like zoom in on a tool path or change screens while the machine is running?

Any thoughts?

Andy Baker


8
Video P*r*o*b*i*n*g / More Lasers = A Better Scan
« on: September 16, 2008, 03:42:22 PM »
Hello -

So I've yet to hook up the laser scanner just yet, but I have some thoughts and past experience I'd like to share.

Once upon a time I built my own laser scanner. It was awesome, and it used two laser beams.. Well, actually one laser, split in to two beams and then broken out in to lines.  The lines came in from either side of the camera and intersected at zero. Here's why - Any sloping surface greater than whatever the laser angle is will effectively mean an undercut that can't get scanned. This was bad for what I was doing. I didn't need dimensional accuracy as much as I needed an accurate visual representation.  Anyway, I didn't use an XYZ gantry, I used a turntable. It was just better for what I was doing, and anyway, I had one on hand. Here's some pictures. Sorry for the high resolution.



Here's the rig in the flesh.



I had a little layout breadboard table I made out of ply. Good for this sort of thing. All the optics were affixed to the various stands. The laser was a big fat 50mW 650nm red - Plenty of power to go through all those lenses and still be seen by the camera. I photoshopped the beam a little bit to make it show up in the foreground.

Here's an animated GIF of the single line version. gotta start somewhere!



and here's the resulting point cloud, complete with noise.



After some processing in crappy VB programs written a long time ago by me, you get this.



next up shots of the second scan.  I ended up taking the brightness of the laser and assigning it to the brightness of the point (in the cloud) This kind of let me weight them visually - After all, I was just drawing these on sheets of styrofoam to cut with a jig saw.  You can see on the left that there are purple and yellow points. these represented either laser. Both lines were scanned at the same time. Processing was done from center to left for one laser, and center to right for the other laser. This was NOT two scans, as in scan once, set up again, scan again, overlay.

This one is big - Scroll sideways. Sorry - Screen capturing from dual monitors makes messes like this.



For another part of the scan (for the sole of this shoe) you can really see where two lasers comes in handy. Blue and green represent left and right laser beams.




Now you guys can pick apart my lack of signal processing, inattention to detail, mathematical flaws, geometric laws bent and broken, but the results were pretty spectacular. After all, I was only going to render the scans by sharpie and jigsaw, so why blow weeks on software when I had foam to turn to dust?




Anyway, a little food for thought for producing the next generation of video scanner plug in software.



Also, a question - Can the plugin scan multiple strips and knit them in to one cloud? Solidworks 08 seems to be able to make sense of the mechanical probe-generated point clouds fairly well, and I've got an enormous machine, and it would be good to be able to scan big things.



Andy


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