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1

Show"N"Tell ( What you have made with your CNC machine.) / Re: "Magic Cubes" for Mach and How to

« on: August 09, 2007, 11:31:29 PM »

Careful, acetone acts as a solvent for some plastics. 
Put a drop inside where you can't see it easily, and wait to see if the plastic get soft or tacky before you go wetting the whole outside surface with it.

2

General Mach Discussion / Re: HELP pleeeeeese Z axis problem !!!!

« on: August 08, 2007, 09:42:40 PM »

Dougie said that when he swapped the y and z axis cables from the controller to the stepper motors, the problem shifted to the y-axis. 
That implies the driver electronics or software config -  pulse widths, pulse polarity and edge detection.
Or did I mis-read the thread somewhere?

If not there seems little point investigating the mechanics of his machine Z axis when now the movement of the Y-axis begins exhibiting the same problems.  Any problems with tight leadscrews/nuts or excessive weight of the Z axis machine head etc are not relevant if the Y axis suddenly starts doing it too.

He also said it did it when jogging around, so the heating affect ought to be minimal.

3

General Mach Discussion / Re: HELP pleeeeeese Z axis problem !!!!

« on: August 07, 2007, 04:44:08 AM »

I took the y drive plug out of the controller and swapped it with the Z plug on the front of the control box and then jogged z using what would normally be the y quick keys. problem didnt occur in z but does now appear in y. I didnt physically shift any wires inside

This proves that the motors were working correctly for both axes, so no need to upgrade those.
The problem occurs between the computer and the controller output.
Based on this it could be the controller board, PC port, or the software (including a software configuration error).

The fact that they state their preferred software works is significant - they probably also provide a config file which sets all the correct software config states up for their machine to operate

x axis is active low, other 2 arent.

X axis pin 2 direction   5v
X axis pin 3 step         5v

Y axis pin 4 direction   5v
Y axis pin 5 step         5v

Z axis pin 6 direction   5v
Z axis pin 7 step         0v ??

Very confusing.
I am wondering if you have mistyped something, and that x & y are active low, and z isn't. 
That would make more sense.
If that is the case, try changing the sense for the z axis step control.

Other thing from left field, is the PC doing something after 5 or 10 mins?
eg maybe a memory cleanup 'garbage collection' cycle or swap file flush etc.

I had a similar problem when I first set up my machine.
Trying to mill a test piece it would skip on the z axis at about the same place everytime (the 3D face test file, doing the fine cut about 5 mm into the side about level with the nose)
I finally fixed this by removing the ACPI chip driver and replacing it with the 'Standard PC' driver.
I presume some long delay interrupt triggers or similar, and windows gets sidetracked too long to drive the motors properly.
Now I have replaced the drivers, the machine has never skipped since.

4

FAQs / Re: System Requirements

« on: August 06, 2007, 11:52:11 PM »

Well, I am relatively new to this, I tried to get my new mill set up with Mach3 last week and had no end of problems.

The officially advised spec was 1Ghz P4 with 512M RAM, and then as many ports as you need to drive your hardware - in my case a single parallel port is all I require. Most systems seem to get away with this but some may need multiple parallel and/or serial ports, otheres may need USB devices or even a custom adapter card. 

Using a fresh install of XP on the machine, it didn't work at all. 
No movement on the steppers.  In fact they were not even energised to hold them still.
Finally discovered that Windows was translating the hardware port address.
After aligning the BIOS address with the windows system driver resource entry and the configuration of Mach3, that was sorted out, but not until after I did a complete power cycle - a standard reboot did not do it!

After I got it moving, I then had problems with the motors 'skipping' while jogging. 
You could hear little interruptions to the tone of the motor.  A bit of 'motor tuning' seemed to fix that, but after a random period of time milling, there would be little 'skips' occurring in the z axis usually that ruined all the pieces I tried to cut.  I could only cut at 50% of the maximum rate - most unsatisfactory.

So I went through and turned of all the services I could find that did not cripple the machine (watch out for the security account manager service ... ) and tried again. 
Marginally better, but still failed.

I decided it must be a lack of processor horsepower, so I threw in a 2.8Ghz AMD machine with a nvidia graphics card, 1Gb of DDR RAM and ... IT MADE NO DIFFERENCE!!!   
I could not believe it.

After another few days of frustration I came across a recommendation on the net that I had overlooked, and it fixed it immediately!
In fact, now that the root problem is resolved I have turned on all the services again, including Antivirus updates, MSN messenger, I run MS Outlook all the time, and the machine is part of an AD domain with the overheads that brings.
Now I often have Rhino 4, LazyCam and Mach3 running all at the same time, with the mill cutting a piece at it's maximum rate at the same time as I'm editting a Rhino drawing and confering online with my colleague via MSN.

The secret is .... disable the ACPI driver! 
Open the device manager and find the 'Computer' icon.
Click on the plus next to that and you will see something like Advanced Configuration and Power Interface (ACPI) computer.  Chose the 'update driver' option and select 'Standard PC' as a replacement.
Windows demands a reboot after this, and a lot of the hardware had to be 'rediscovered' and reinstalled (all used drivers it knew about already, so was painless), another reboot for good measure and now it works flawlessly.

I tried to put the original machine back in, with the the ACPI driver removed, but it still has the occasional hiccup so I think the minimum spec needs to be >1Ghz with 512M, but mine is plainly overpowered now with all the usual windows stuff running without affecting the milling operations at all.