Wrong G81 Z retract

More
23 Aug 2011 11:22 - 23 Aug 2011 11:25 #12666 by ArcEye
Replied by ArcEye on topic Re:Wrong G81 Z retract
andypugh wrote:

I wonder if the % at the beginning is cancelling a modal G98 code somehow?


I thought that G99 was the default behaviour unless you specifically programmed a G98?

There is no G98 or G99 in plasdoms code and my simulator shows G99 as the active G-Code.
The movement I saw coincides with that retraction model.

However I think I have solved the mystery.

The code does not start anywhere, just jumps straight into G81.

If you place Z at 2" before calling G98, the program retracts to Z2 every time after drilling a hole

regards

eg

g17 g20 g40 g49 g54 g80 g90 g94

G0 Z2
G98

g81 f8 x.225 y-.125 r.08 z-.02
Last edit: 23 Aug 2011 11:25 by ArcEye.

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 11:33 - 23 Aug 2011 11:33 #12667 by piasdom
Replied by piasdom on topic Re:Wrong G81 Z retract
Cool, but this is an old file i use many times. never changed anything
til it went coco:). i added the below to the start. retracts to where it
should but plot is wrong on bottom holes. shows z0, but runs at z-.75.
added g99 to below and plot shows correct path.

g17 g20 g40 g49 g54 g80 g90 g94 g92.1
(C-Drilling)
m6 t5
g0 x.1 y.1
z.2
g81 f8 x.225 y-.125 r.08 z-.02

p.s. i have no % in file
Last edit: 23 Aug 2011 11:33 by piasdom.

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 11:47 #12668 by piasdom
Replied by piasdom on topic Re:Wrong G81 Z retract
i tried g98 below and the plot changed back to wrong retract on
bottom holes. and all holes retract to 2". if g98-99 are for z retract,
what is the 'r' for in g81? used g81 for two years now, first time
all goes coco:)

g17 g20 g40 g49 g54 g80 g90 g94

G0 Z2
G98

g81 f8 x.225 y-.125 r.08 z-.02

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 11:54 #12669 by piasdom
Replied by piasdom on topic Re:Wrong G81 Z retract
ran dmesg and found below. this could be my trouble ?




[ 195.229143] RTAPI: ERROR: Unexpected realtime delay on task 1
[ 195.229163] This Message will only display once per session.
[ 195.229164] Run the Latency Test and resolve before continuing.
[ 676.316260] PNPBIOS fault.. attempting recovery.
[ 676.316263] PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue
[ 676.316265] PnPBIOS: You may need to reboot with the "pnpbios=off" option to operate stably
[ 676.316267] PnPBIOS: Check with your vendor for an updated BIOS
[ 676.316270] PnPBIOS: set_dev_node: unexpected status 0x3a
[ 676.316272] probe_parport 00:0b: disable failed
[ 676.396251] RTAI[math]: unloaded.


File Attachment:

File Name: dmesg.txt
File Size:44 KB
Attachments:

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 12:51 #12670 by ArcEye
Replied by ArcEye on topic Re:Wrong G81 Z retract
Another thing to sort out, but I can't see how, not going to change how G81 picks up the Z axis position.

What I found goes back to what Andy said at the beginning

My impression was that it would always retract to the last G1 Z position, not anywhere jogged to. I didn't check G0.


It looks like G81 uses the last linear move to a position for Z and does not read it's actual position.
It would anticipate a move like G0 X0 Y0 Z2 as a precursor to any G81 canned cycle

If you move to a location by jogging and then run G81, as effectively your program does, it has no Z position set by a move and it acts as observed.

regards

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 13:09 - 23 Aug 2011 13:12 #12671 by piasdom
Replied by piasdom on topic Re:Wrong G81 Z retract
just wondering if the developers changed something or if something
changed on my comp i don't know about. if i use below, file runs as should.
doesn't use .2" as retract.. uses .08"

g17 g20 g40 g49 g54 g80 g90 g94 g92.1 g99
(C-Drilling)
m6 t5
g0 z.2

g81 f8 x.225 y-.125 r.08 z-.02


and i seen epp somewhere and saw it today in the bios.

selections;
normal
bi-directional
ecp
epp
ecp & app

set at bi-dir.. does this matter to emc or is this
for printers ?

Thanks
kenneth
Last edit: 23 Aug 2011 13:12 by piasdom.

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 13:36 #12673 by BigJohnT
Replied by BigJohnT on topic Re:Wrong G81 Z retract
Kenneth,

I ran the file on the 2.4.2 Axis sim and got the expected retract points... I'll go down to the beer cave and see what 2.5.x does.

John

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 13:44 - 23 Aug 2011 13:45 #12674 by piasdom
Replied by piasdom on topic Re:Wrong G81 Z retract
Thanks John,
maybe i should go back to 2.4 ?



kenneth

p.s. got 2.5 to use glade, but somein rong.
don't really need now.
Last edit: 23 Aug 2011 13:45 by piasdom.

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 13:49 #12675 by BigJohnT
Replied by BigJohnT on topic Re:Wrong G81 Z retract
Nope, runs fine on 2.5 too.

On the DRO tab do you have a leftover G92 offset that was not cleared by some other program that you ran?

John

Please Log in or Create an account to join the conversation.

More
23 Aug 2011 13:57 #12676 by ArcEye
Replied by ArcEye on topic Re:Wrong G81 Z retract

and i seen epp somewhere and saw it today in the bios... set at bi-dir.. does this matter to emc or is this for printers ?


BIOS should set the parport as EPP for emc

Bi-directional is for older printers and devices to be able to report back ink levels, confirm ready for next data packet etc. as far as I am aware.
Was overtaken by IEEE 1284 ECP for most new printers.

Whilst EPP is bi-directional, there is a different protocol.

regards

Please Log in or Create an account to join the conversation.

Time to create page: 0.329 seconds
Powered by Kunena Forum