Messages

21

G-Code, CAD, and CAM discussions / Peculiar Z movement

« on: April 30, 2006, 05:12:27 PM »

I am getting a peculiar Z movement from mach3 (lockdown version) when running this code which is at the beginning of a job:

N60 G00 G20 G17 G90 G40 G49 G80
N70 G00 Z1.0
N80 X0.0 Y0.0 Z1.5
N90 M06 T1 G43 H1  ( Slot Drill )
N100 G94 S1000 M03
N110 X0.4375 Y0.1875 Z1.5
N120 X0.4375 Y0.1875 Z0.1181
N130 G01 X0.4375 Y0.1875 Z-0.015 F1.5
N140 X0.4375 Y0.2095 Z-0.015 F2.0
N150 X0.1655 Y0.2095 Z-0.015
............................

The Z axis initially drives to 0.5 inches  then drives up to 1.5"

Watching the DRO it ramps up to 1.5" and immediatly resest to 0.5" so the z movement reflects the DRO setting in its final position but does not get the chance to move to 1.5".

I have also noticed that a 1" Z error sometimes occurs in that the Z axis drives to 1.5" and then drives up another 1" so on the way down it is cutting air. On these occasions the DRO indicates 1" when it should be down to 0.

The common factor tseems to be this mysterious 1" that occurs.

Any ideas around that might account for this behaviour?

Alan

22

General Mach Discussion / Re: Odd Z movement

« on: April 07, 2006, 04:40:04 PM »

That would be very welcomed indeed.

23

General Mach Discussion / Re: Sony laptop

« on: April 07, 2006, 04:27:52 PM »

I am running Mach3 on a "Toshiba satellite" laptop 1.7Gh processor, 512Mb RAM, Windows XP, using single parallel port output/input via a CNC4PC parallel breakout board.
No Antivirus software running.
Seems OK so far.

24

General Mach Discussion / Re: Odd Z movement

« on: April 07, 2006, 09:10:44 AM »

Now I have started this hare running I get more questions than answers!

Looking at the Mach3 Offset page I see the Z offset as 1.000 but the button to toggle the offset on/off does not seem to have any affect.... the LED's remaon permanently lit.  Why?

I then started to think why was the G43 command there anyway as I had not specified any Z offset to be used. The tool definition has its length set to 1.000" but that is all. So where is the Z offset figure generated from?

Perhaps I do not understand the significance of the tool length definition?

When I set the machine up I jog the Z axis down to get the tip of the tool touching the work surface ( zero plane) and set Z to zero. Set the X and Y up and set them to zero, regen the tool path and the work cuts at the correct plane. So I seem to be doing it OK but now I am unsure I understand what I am doing! ..... in respect of the Z axis and the tool length and offset.

Anybody care to give an idiots guide?

25

General Mach Discussion / Re: Odd Z movement

« on: April 07, 2006, 08:00:08 AM »

It's always the way isn't it ....... make a post and then see the answer!!

Its the G43 tool length offset that seems to be doing it .... but why I see it sometimes and not others is a bit confusing.

26

General Mach Discussion / Odd Z movement

« on: April 07, 2006, 07:50:51 AM »

I am experiencing an odd Z movement with the code posted below. The code is only the begining few blocks of a profiled surface.

The peculiar Z movement seems to occur after line 70 having driven to 1.9685 (I know its a funny number but it is a function bug in Dolphin CAM I think)
then for some reason Z goes to 1" until the next Z command occurs

Stepping the blocks one at a time shows this up. But it is not consistant as sometimes it does not occur.

I have run the prgram on two different PC's with the same result.

Any advice on what might be happening?

Code:
 Produced       :- 10:28:57  Friday, April 07, 2006 )
( CNC File       :- joggle1 )
( Post Processor :- M_MACH_3 )
( Part Number ID :-  )
(Program Number :- O100  )
N60 G00 G20 G17 G90 G40 G49 G80
N70 G00 Z1.9685
N80 X0.0 Y0.0 Z2.0
N90 M06 T2 G43 H2  ( End Mill )
N100 G94 S1000 M03
N110 M08
N120 X0.0 Y-0.125 Z2.0
N130 X0.0 Y-0.125 Z0.0625
N140 G01 X0.0 Y-0.125 Z-0.0024 F2.0
N150 X0.0 Y-0.3576 Z-0.0024
N160 X0.0 Y-0.3676 Z-0.0024

27

General Mach Discussion / Re: Screen 4

« on: March 30, 2006, 10:49:36 AM »

Many thanks, ........ having sorted the LED out I find that when mach3 starts the LED does not show. When the button is pressed to which the LED relates then it does show and subsequent presses will make it turn off and on correctly.

So why does it not show on initial screen load do you think?

The Led is associated with the jog on/off button being placed on a new screen.

28

General Mach Discussion / Screen 4

« on: March 29, 2006, 11:29:46 AM »

How do you delete an item in screen 4?

Having wrongly placed a LED on screen I cannot find a delete facility. The Cut button is greyed out.

29

General Mach Discussion / keyboard jog control

« on: March 28, 2006, 11:43:49 AM »

Why is it that with some screen displays on Mach3 the keyboard jog controls work and on others they do not?

I have not changed the Mach3 screens or anything else from the latest lockdown download version.

30

General Mach Discussion / Re: Mach3 and mill set up

« on: March 21, 2006, 10:31:50 AM »

I guess that is exactly what I have ...... the cross hairs represent the tool travelling to the work and match the direction of the arrow keys.

providing you do not look at the table when jogging then confusion is unlikely, but if the attention in the brain cell goes absent then instinct pushes the arrow button for the direction you want the table to travel.

I suppose with a gantry machine where the work is stationary and the tool moves it works fine but for an engineering mill where the tables move beneath a fixed position quill then the spatial difference can become a headache!

Thanks for the response anyway.

Alan