Messages

1

General Mach Discussion / Simple, Simple question about home.

« on: April 27, 2011, 04:39:46 PM »

I lost the config to my machine, and I'm recreating it. This is my last challenge:

How can I tell Mach3 to start somewhere other than 0,0? I have limit switches that set home, but I have a fixture mounted an inch or so away, and want it to always start from there. I'm sure I'm missing something obvious, but the more I play with it, the more frustrated I get, and I'm not getting any closer.

2

General Mach Discussion / Re: Parallel Port woes - need advice

« on: April 13, 2011, 03:06:04 PM »

Well, after lots of fiddling, uninstalling, reinstalling, rebooting, etc, I got it working with the PCI card. I'm tempted to see if I can get it working with the on-board Parallel port, but you know what they say when something's not broken...

Thanks everyone!

3

General Mach Discussion / Re: Parallel Port woes - need advice

« on: April 13, 2011, 09:33:08 AM »

Wow, thanks for the replies! Man, I'm a dope. I just realized that, if I install a new Parallel port, I actually have to plug my CNC machine into that parallel port! Anyway, things are partially working now. Motors move, Charge Pump works (Basically all outputs), but limit switches and estop doesn't. My new parallel port looks kinda wonky in the setup. Most, if not all parallel ports I've seen have two ranges, and a DMA. Mine only has one (D880), and an IRQ if I set it. From a vague memory, I think the second port is basically for input. I'd think it's not in EPP mode, but I don't see where to change that. So, my question turns to... Has anyone set up a PCI Parallel port card using a MCS9865? I've seen mention of this chip elsewhere on here, and selected this card as at least somebody seems to have got it to work. I used the latest drivers from Moschip's website.  Thanks again!

4

General Mach Discussion / Parallel Port woes - need advice

« on: April 13, 2011, 01:16:52 AM »

I had Mach3 installed on a touch screen computer using a via chipset and CPU, running Windows 2000, and it worked great other than being slow. I bought a Pentium 4 based touch screen computer, installed a fresh Windows XP, Mach3, copied over the config, and hooked it up to my existing CNC. It seemed like the parallel port was completely dead. No heartbeat to turn on my G540, no limit switches detected, nothing. I uninstalled and reinstalled Mach3, and tried to set it up manually. I thought maybe the new port couldn't supply enough voltage or current to the G540, so I got a C26 buffer board from cnc4pc.com. Nothing. On the BIOS, it was set as EPP, but I try ECP and Bi-Directional as well, with the same results. I disabled the parallel port on the Motherboard, and installed a Moschip MCS9865 based PCI Parallel card. Same result (Although there weren't any port address settings in the driver, I selected LPT1, LPT2, and LPT3.) I suspect nobody will know exactly what's wrong in my particular situation (I still welcome advice!), but I'm hoping someone could suggest some tools for troubleshooting the parallel port. My bag of tricks is empty.

5

General Mach Discussion / Re: Weird problem with Mach3 and tool paths

« on: March 21, 2011, 10:35:18 AM »

Actually, the small radius was put in to hopefully work around the Mach3 bug. It didn't fix it completely, but I used to make usable parts. Then I dropped the whole project for a year or so, and when I started with the latest Mach3, it didn't work anymore.
Well, hopefully they figure it out. Thankfully, Graham's code works perfect for me, so I now do cutter compensation with D2NC. It just gets me nervous that code that I believe should need to be rock solid has had known bugs for years.

6

General Mach Discussion / Weird problem with Mach3 and tool paths

« on: February 12, 2011, 02:27:05 AM »

Using D2NC, I generated the code below. Two really weird things happen in Mach3. First, while the part shows up fine, the tool path around it is crooked in places!. Second, if I click run, it doesn't even follow the tool path, but makes first a circle about 1/4 smaller than the part, then traces the circle again. Once in test, the second circle was MUCH bigger. The author of D2NC seems familiar with this problem, but I really hate bugging him to work around a Mach3 problem.  Can anyone help with this?

(D2nc generated code)
 
G17  (set xy plane)
G90  (absolute mode)
G40  (cancel cutter radius comp)
G49  (cancel tool len offset)
G80  (cancel canned cycle)
G50  (reset scale 1:1)
G91.1 (IJ relative arcs)
G20  (inch mode)
 
(Tool diameter: 0.01 )
M05  (stop spindle)
M06 T0 (tool change)
M03 S1000 (spindle on)
 
G00 Z1
G00 X0 Y0
G00 X-.0150 Y-.0625
G42 P.0050
G00 Z.1000
G01 Z-.0100 F0.5
G01 X-.0075 Y-.0625 F1
G02 X.0000 Y-.0700 I.0000 J-.0075
G01 X.0000 Y-.1400
G01 X.0000 Y-.1400
G01 X.0000 Y-.2800
G01 X.0250 Y-.4400
G01 X.0250 Y-.2800
G01 X.0500 Y-.2800
G01 X.0500 Y-.4400
G01 X.0800 Y-.2800
G01 X.0800 Y-.1400
G01 X.0800 Y.0000
G01 X.0000 Y.0000
G01 X.0000 Y-.0700
G02 X-.0075 Y-.0775 I-.0075 J.0000
G40  (cancel cutter radius comp)
G01 X-.0150 Y-.0775
G00 Z1
 
M05  (stop spindle)
M09  (all coolant off)
G00 X0 Y0
 
M30  (end with rewind)

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General Mach Discussion / Re: Y Axis Issues

« on: January 07, 2011, 04:26:47 PM »

Thanks for the responses. I think I didn't have my coffee before my last post. My CNC is set up like an engraver. If home is in the lower left, the tool will be in the way, and I'll have to always jog the cutter out of the way to access the work area. Since this is my first homemade engraver-type of CNC, I was going on my experience with an old New Hermes CNC engraver I used years ago, where 0,0 was upper left.

My G-Code is made by a script in D2NC. It was originally putting the output in the upper right quadrant, but I modified it to put it in the lower right quadrant.

I don't want to go down the wrong path, and cripple myself later with things like the toolpath not showing correctly. It's not too late for me to change the fixture, or my G-Code. What's the accepted way of handling this situation?

8

General Mach Discussion / Re: Y Axis Issues

« on: January 07, 2011, 10:09:20 AM »

Well, I have a fixture for cutting plexiglas sheets, and to hold it in the fixture, I push it into the upper left corner, with hold downs around the bottom and right edges.

9

General Mach Discussion / Y Axis Issues

« on: January 07, 2011, 01:16:25 AM »

I'm setting up my new machine (A Zen Toolworks Plastic-frame CNC), and I wanted to set up 0,0 in the upper left corner, and have what's displayed in the preview window cut out with the same orientation. However, I'm having a nightmare trying to set up the Y axis. I've tried every combination of 'Dir Low Active', and on the motor home/soft limits screen, 'Reversed', and 'Home Neg', and I haven't been able to configure it right. What I want to do is have it home right, move properly when I jog it (Yes, the Y will move opposite, but correct relative to the cutter), and have the DRO numbers move in the positive direction when moving away from 0,0. Is there a setting I'm missing? Am I going about all this wrong?

10

General Mach Discussion / Re: Continuing a job after an event stops it

« on: October 12, 2008, 07:05:48 PM »

I want to thank everyone for their responses. I've got limit switches, and they are prone to vibration (Used to be able to trigger a stop by lightly banging on one with a screwdriver handle), but I upped the MS it takes to register, and has just about eliminated all bounce. If I recall right, this was an ESTOP, which hasn't happened on it's own before. My material is just a few square inches of plexiglas, so I think I'll just start over if it happens again. I'm very new to CNC, and I was just curious if there was a reliable, established way to restart things, but for me I don't think I'll try. If it happens more regularly, I'll address it from the prevention point of view.