Messages

21

General Mach Discussion / More Z-axis difficulties...

« on: April 14, 2012, 01:23:41 PM »

It's been an interesting week. The computer I was using to run Mach3 and my
HobbyCNC driver board had a motherboard and power supply failure. Was able to
get a used HP COMPAQ DC7 in its place... Everything computer-wise seems to be
back in order.
HOWEVER I am running into Z-axis slippage(?) that I can't seem to troubleshoot:
My foam patterns take roughly 5-1/2 hours with both primary rough and secondary
finish cuts.
The primary always seems to run fine, but at variable places along the secondary
finish cut, the Z-axis looses its place and plunges the cutter twice as deep
into the pattern.
I did notice a 'stall' on the Z-axis when I did a fast move with Page UP and
Shift keys just now...
This may be indicating an intermittent problem with the motor itself?
I've already lowered my motor tuning lower than earlier working speeds.
In fact I recently had to replace my X-axis motor (425oz bipolar) for slippage
problems...
But I thought these motors were supposed to be pretty hardy...
More info...
I did a REF HOME for machine coordinates before starting the pattern.
I found my start point on the pattern and zero'd the X, Y, & Z coordinates, but
then went to the Machine Coord to see what that reading was: X .4133, Y .3504
and Z -0.6799
After the rough cut, the machine was supposed to relocate to the original X 0, Y
0 start point with the Z being at 1.5 for the tool change...
But when I brought the Z axis down to 0 to check the Machine Coord now read
-2.0334, instead of -0.6799
So is it motor slippage, or something else going on?
Not sure how to proceed...
So I decided to try just the finish cuts and eliminate the tool change.
But even that failed... each X-axis pass had the Z-axis plunging deeper...
(Yes, the Z-axis is rigid to the motor and table...)
Thanks for any insights...

22

General Mach Discussion / Re: Computer Catastrophe... Best Solution?

« on: April 13, 2012, 05:24:02 PM »

Thanks for info, Guys!
The original computer had a fried motherboard and power supply.
The good news, the hard drive was OK.
Able to go to a local computer repair and get a used HP COMPAQ DC7 mini-tower loaded with XP Professional for a reasonable price.
They also had a small cabinet for the old hard drive so I could access the contents on the new computer.
Did a Mach3 re-install and was able to retrieve my XML files.
Took an hour or so, but everything is up and running again!
Life is good!  ; - )

23

General Mach Discussion / Computer Catastrophe... Best Solution?

« on: April 06, 2012, 05:20:16 PM »

It's been an interesting couple of days...
This morning I discovered that my desktop XP computer was still trying to turn itself off from the previous day's CNC router work.
The drive light would periodically flash, but there was no way to get any keyboard control.
I did a hard restart, but there was no restart...
The drive light would simply light up, but the computer never initialized...
Today it won't start at all...
Sooooo....
Now I must consider my options:
Using my alternate Laptop using Windows 7 would require a CNC motion controller board according to Mach3 recommendations...
But these boards appear to be plug-ins requiring their own power supply.
Plus they are a tad pricey!!!
Alternately, buy a cheap new desktop and get a USB to printer port converter to drive the HobbyCNC driver board...
I'd love to retrieve the custom Mach3 settings I'd had on my old computer, but no, I did not back them up to a different storage medium... (sigh...)
I'm pretty sure I've got them written down somewhere, but where...
I need a pretty quick solution to this problem, as my business is now shut down.
What would you do?
Besides having backed up your critical files on a different storage medium...
Chet

24

General Mach Discussion / Re: Strange shift in Z-axis during machining

« on: April 06, 2012, 09:24:11 AM »

Once again, guys, thanks for the feedback.
The capacitors were installed awhile back.
And I think I'd rather live with a 'random event' than turn off the shop vac and have all that foam dust hitting the air...
Should the event happen again, I'll have to switch over the machine coordinates and see what the z-axis says...
Good thought, there...

25

General Mach Discussion / Re: Strange shift in Z-axis during machining

« on: April 05, 2012, 10:04:54 AM »

Thanks to all for their thoughts!
I use 3/8-12 Acme threaded rods and nuts for my drive systems and a high-temp lithium axle grease.
The CNC router is in the basement, so weather conditions tend to be standard.  ; - )
Motor Tuning Acc & Vel are actually set below maximum already.
So the random Act of God may be the best explanation...
However, I did discover another artifact that may, or may not, have some bearing on the operation...
In the Config File, I typically have the program switch off (Enable command) my router and vac at the end of run or M30.
Because of other surprises in the past I also checked the Emergency E-stop as another Enable trigger.
During one run, the E-Stop was activated by a single line of code, yet the router was in a safe area!
And it would only happen at that line of code...
Nothing mysterious, just numbers for the X, Y and Z axis motors.
Turned off the E-Stop notification, and everything ran correctly.
Perhaps an exorcism is more appropriate...

26

General Mach Discussion / Re: Strange shift in Z-axis during machining

« on: April 05, 2012, 07:55:53 AM »

Thanks, Hood, sounds like a reasonable analysis.
But why would this effect only happen intermittently?
I can have hours of correct machining before this anomaly presents itself...
Chet

27

General Mach Discussion / Strange shift in Z-axis during machining

« on: April 04, 2012, 08:47:07 PM »

About 4 hours into a 5-1/2 cut, the Z-Axis shifted an additional 0.1875 inches down.
This was not mechanical slippage, as the pattern continued to be cut correctly, just at a deeper depth.
It sounds like the zero Machine Coordinates for the Z-axis somehow shifted to my depth of cut - 0.1875
A 2nd attempt to cut the pattern turned out without any problems.
Anybody have a thought on this?
Especially on how to avoid this anomaly in the future?
(I tried to include a photo, but can't seem to figure out the system here.  Yes, the photo was small enough in size...)

28

General Mach Discussion / Mach3 momentarily losing its place...

« on: December 06, 2011, 03:13:17 PM »

I've run into a new problem with my Mach3 which is running my CNC router.
For a period of 15 minutes or so, the cut became totally distorted with all X, Y, and Z axis movement shifted...
But it then resumed cutting correctly!!!!
The only variable I can think of was the use of a nearby portable electric drill...
I'm going to try and attach a photo of the problem.
Any insight will be appreciated!
Chet

29

General Mach Discussion / Mach3 mentioned in SEP 2011 'Wired' magazine!!!

« on: August 27, 2011, 02:12:34 PM »

Page 62... Article on Pro Fabbing.
Reviews Tormach PCNC770 as a desktop work station.
The Tormach gets a rating of OK for hobbyiest use as it doesn't seem to hold tight tolerances.
However, quoting, "...which comes prefigured with the industry-standard Artsoft Mach3 software...
Cool!
Chet

30

General Mach Discussion / Re: Adding audible alarm to Mach 3 thru HobbyCNC board...

« on: August 27, 2011, 01:35:36 PM »

Success!!!!!
The C-37 single relay board from cnc4pc.com is an excellent little unit.
No 10k pull-up was necessary!
Pulled 5 v off the HobbyCNC board to power it, and attached the input to pin 14.
Wired the vac in on the NO pins of the relay.
Didn't need an extra in-line switch as the vac already has one!
Sweet!!!!!
Thanks to every for their suggestions!
The idea of turning something off as an alarm was a stroke of genius!
Many thanks to all who participated!