G92 threading cycle

[paul]

Hi
when trying the G92 example from the help files it only does 1 threading pass then just steps in one line at a time for each X value without making a cutting pass. The example looks right so could it be a bug perhaps?
Cheers
Paul

NØØ5Ø GØØ X16.25 Z5.Ø ;
NØØ6Ø G92 X15.6 Z-4Ø.Ø F2.Ø ;
NØØ7Ø X15.2 ;
NØØ8Ø X14.8 ;
NØØ9Ø X14.5 ;
NØ1ØØ X14.2 ;
NØ11Ø X13.9 ;
NØ12Ø X13.9 ;
NØ13Ø X13.546 ;
NØ14Ø X13.546 ;

[jaycnc]

G92, X,Y and F values need to be specified in each line.


G92 X?? Y?? F??
G92 X?? Y?? F??

[Denford Admin]

You're right - the example seems to be suggesting G92 is modal - ie, all subsequent lines will carry out a G92 until another G code (eg G0/G1) is programmed

I'll report it as either an error in the example, or a bug in the software.

[dubstar_04]

You're right - the example seems to be suggesting G92 is modal - ie, all subsequent lines will carry out a G92 until another G code (eg G0/G1) is programmed

I'll report it as either an error in the example, or a bug in the software.

I'm having issues with this at the moment. Did this ever get fixed?

[bpmsl]

Hi folks, more threading weirdness.

With the DOS control software my novaturn threaded perfectly, in VRTurning it seems to cut the threads compressed in z.

I discovered that for my 1999 novaturn the steps per mm were different from the default machine setup in the latest VRTurning so I had to change them from 160 to 200 (I also changed the steps per F setting). Are the number of encoder pulses different too? (viewtopic.php?f=42&t=3515)

Also the following block of code runs well on its own (apart from the threads being compressed in Z):-

(THREAD1)
M1
T0101
M06 T0101
G99
G50 S3500
G96 S548 M3
G0 X33.6 Z5.542
G0 Z7.242

G92 X8.938 Z-4.458 F1.5
G92 X8.498 Z-4.458 F1.5
G92 X8.16 Z-4.458 F1.5

G0 X33.6 Z5.542
G28 U0.

But if the above is executed in the whole programme (file attached) after the T0101 tool change and one if not both of the G0 moves the lathe sends the cross slide up to max x and then slowly descends and would crash the tool If i don't stop the programme.

The code is from a fettled Fusion 360 FANUC lathe post.

Any thoughts would be much appreciated.

Cheers
BPM

[bpmsl]

Hi folks, more threading weirdness.

With the DOS control software my novaturn threaded perfectly, in VRTurning it seems to cut the threads compressed in z.

I discovered that for my 1999 novaturn the steps per mm were different from the default machine setup in the latest VRTurning so I had to change them from 160 to 200 (I also changed the steps per F setting). Are the number of encoder pulses different too? (viewtopic.php?f=42&t=3515)

...

Any thoughts would be much appreciated.

Cheers
BPM

Further info my Novaturn Encoder is marked as PPR 2000.

The default VR Turning spindle "encoder count" for the novamill in teh latest software is 4000, should I change this to 2000 to match my encoder? Or is there some gearing to consider?

Any thoughts would be much appreciated.

Cheers
BPM

[TDIPower]

Would love to be able to help, I'm yet to get my lathe changed over from DOS to VR, interested in where/how you got the Fusion post processor. I could only find one for milling which works well.

I would give it a go on changing the value though, if it works great, if not just change it back!

Pete

[bpmsl]

Hi Pete,
I've been working with the post developed here
https://groups.google.com/forum/m/#!msg ... 14WNt0AQAJ

It's a work in progress. I'll upload a fettled version when I'm happy it's working relatively well.

I'm going to optical tachometer the spindle and see if the speeds are right. I'm beginning to think the reason for the spindle getting warm might be because its been running at double speed so maxing out at 7000 rpm. If so I hope I haven't damaged the bearings.

We will see! Will post an update when I know more .

Cheers
Barry M

[TDIPower]

Cheers for that Barry, I had seen something about the Nottingham hack space a while ago, I think I even dload a file but couldn't get fusion to 'see' the postprocessor file. Really hope you can sort the issue out on yours and the Fusion processor too.

My lath conversion is well on the back burner yet again, I had set myself the task of rebuilding the axles on my Landrover this week, it's gone a bit mad and a chassis is now on order! Mind you that job has been on the back burner for 13yrs!

Pete

[dpslwk]

I'm currently trying to rewrite the Fusion 360 Post processor to correct drilling and threading cycles

Just trying to get G92 working and need to file a BUG in VR Turning, seen in v1.33 and v1.51
I'm only doing this in the simulator / virtual machine right now as I'm not near the our Novaturn.

Using the correct modal format and Setup->View Cycle Expansion shows the issue/

line N645 G92 X11.434 Z-21. F1. runs correct
but in the following line N650 X11.034 its is correctly trying to expand the cycle to G32 but has a Z10004 (way off the scale), and not correctly remembered from the previous Z-21

Screenshot 2020-01-26 at 14.33.13.png (33.32 KiB) Viewed 19668 times

Code: Select all

O1003
(MACHINE)
(  VENDOR DENFORD)
(  MODEL NOVATURN)
(  DESCRIPTION DENFORD NOVATURN LATHE)
(T0505 NR=0. - ZMIN=4. - THREAD TURNING)
N10 G21
[BILLET X12. Y12. Z60.
N15 G98
N20 G50 S6000
N25 G28 U0. W0.

(THREAD2)
N610 M01
N615 T0505
N620 G54
N625 G99
N630 G97 S400 M03
N635 G00 X40. Z5.
N640 G00 Z4.
(LATHE DRILLING ONCYCLEPOINT- THREAD-TURNING)
N645 G92 X11.434 Z-21. F1.
N650 X11.034
N655 X10.633
N660 X10.233
N665 X9.833
(LATHE DRILLING ONCYCLEEND- THREAD-TURNING)
N670 G00 X40. Z5.

N675 G28 U0. W0.
N680 M30
%