Backlash not working anymore in LinuxCNC v2.9.x

Build my own laser CNC machine about 4 years ago, which worked fine with LinuxCNC 2.8.2.
Using an RPi 3B+, laser and 2 x L293D controllers and 28BYJ-48 steppenmotors.

After trying to update Debian to trixie the SD-card would not boot anymore, so build new one (back to Bookworm).
(Although i can get the old data from LinuxCNC of the card.)
Debian Trixie is not that RT compatible as written all over, still need an RT version to run LinuxCNC on RPI 3B+.
Pitty there is no complete RPi 3 (only 4 and 5) version of LinuxCNC available anymore?

After installing LinuxCNC v2.9.6 (on Debian Bookworm) I could not get the machine working as it did with v2.8.2.
I also changed X-axis steppenmotor with a spindle drive to make it more accurate, this works fine (backlash between 0.1 - 0.3),
but after this I still have trouble with the Y-axis (on which i did not changed anything).
Before (v2.8.2) the Y-axis had a backlash of 1.315, but now I can not get it right anymore.
It looks like the backlash is now only working in 1 direction and I do not see the backlash correction back on the motor movement.
Even if I make the backlash much bigger, just to see if is really done by the motor.
It only draws (i.e. circles) bigger, but the error stays (see IMG_4618a.JPG with BL of 1, 2 and 3)

My question is what has been changed in v2.9.x according the backlash, as I only find 'improved'.
In my case it is not improved but getting worse.
Maybe the new changes do not work with my controllers (L293D)?
And how to solve this weird issue.

Reagrds, DG 

 

Juergen
Very well done and extremely inspiring!!!
Thanks for sharing. I happen to have one of these gampads trailing around somewhere. Off searching
Greez
chris

Hi all, can someone help me with "setp cia402.x.pos-scale xxxx" value?
I've this type of motor with the same encoder: EMMB-ST-87-M-SM (X), EMMB-ST-87-M-SMB (Z1,Z2,Y1,Y2).
Z1, Z2 5mm/rev; X, Y1, Y2 180mm/rev but I don't know the correct pos-scale value.

Unser Plasmaschneider Hevy-Metal hat diese Jahr gute Dienste und schöne Ergebnisse geliefert....
Des halb haben wir uns entschlossen das THC nach zurüsten....
Erste Frage da wir damals die falsche Firmware genommen ( 7I96S_7I74 )haben gibt es ein Chaos wenn wir auf 7I96S-dpl gehen ?
Frage zum THCAD2 High isolation A-
10 V Full Scale
Wiederstände sind ok
Da der Plasmaschneider etwa 103 V beim Schneiden abgiebt was sich mit den Typenschild decktist die frage kann ich auf 150 V gehen für die Wiederstands berechnung oder sollte man auf 200 V gehen ?
Output Frequency ??Mode F/32 oder weiche für die 7I96S ?
Die Eingänge auf der 7I96S Endcoder-Stecker immer die beiden unteren wie in Beitrag 
MESA THCAD-2 - couple quick questions ?

Das war es fürs erste.

---

Our Heavy-Metal plasma cutter has served us well this year and delivered great results.... Therefore, we've decided to upgrade to the THC....
First question: Since we used the wrong firmware (7I96S_7I74) back then, will there be any problems if we switch to 7I96S-dpl?
Question regarding the THCAD2 High Isolation A-D
10V Full Scale
Resistors are OK Since the plasma cutter outputs about 103V during cutting, which matches the nameplate, the question is: Can I use 150V for the resistor calculation, or should I use 200V?
Output Frequency? Mode F/32 in the THCad 2 for the 7I96S?
The inputs on the 7I96S encoder connector are always the two lower ones, as in the post "MESA THCAD-2 - couple quick questions" ?
That's all for now.

king regard e Juergen

Thanks, I'm on the way to a solution for the drivers, what's left of the cables is clear to me, and the rest are: analog +-10v signals, one 25pin input cable, which are partly connected as soon as the machine is turned on, and partly I realized which ones are for homing and for inductive sensors from the tool. and this 25 pin output cable remains, there are a total of about 10 outputs, my plan is to activate them all manually, together, by hand out of 7i77card, to see what will happen on the other side of the machine where this TB3 (see schematic) terminal block is. the cable from the pendant remained, that is, the one  from external buttons to the controller, I mean jog, feed override, spindle override, axis select, step select, estop. I will have to find a way to activate the K1 switch, it turns on the drivers, but also to connect the estop to turn it off. My question is, do I need analog inputs for the pendant later, or could a configuration be made using buttons and potentiometers that would support mpg, potentiometers and buttons with digital inputs?

Hallo Hermann,

bin knapp bei Wien - Deutsch-Wagram

Ich bin mit der Raspberry + Parallel Port Adapter Lösung sehr zufrieden.
Zwei 3-Stunden Jobs liefen am Wochenende problemlos durch:
 

In der Hobby Werkstatt ist mir das Tempo relativ egal, zumindest solange es im Wasserbad läuft und somit keine Absaugung daneben plärrt.

Hi, 

I'm a new user of LinuxCNC, and want to try the qtdragon interface.
I made a recent LinuxCNC installation using the downloadable image.

The problem is that the interface crash when I try to translate the 3d viewer.
In addition :

• Only the qtdragon and qtdragon_hd seems to have the problem, all the other interfaces I tried (provided with linuxcnc) are working normally.
• Only the translation (left mouse + drag) crash. Sometime immediately, sometime after 1-2 move.
• Zoom and rotation works normally.

ThanksTraceback (most recent call last):File "/usr/lib/python3/dist-packages/qt5_graphics.py", line 1057, in mouseMoveEventself.translateOrRotate(event.pos().x(), event.pos().y())File "/usr/lib/python3/dist-packages/glnav.py", line 374, in translateOrRotateself.translate(x, y)File "/usr/lib/python3/dist-packages/glnav.py", line 319, in translatewin = gluProject( obj_c[0], obj_c[1], obj_c[2])^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^File "/usr/lib/python3/dist-packages/OpenGL/latebind.py", line 63, in __call__return self.wrapperFunction( self.baseFunction, *args, **named )^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^File "/usr/lib/python3/dist-packages/OpenGL/GLU/projection.py", line 34, in gluProjectraise ValueError( """Projection failed!""" )ValueError: Projection failed!

sorry for the misunderstanding. i'm using hardware with mesa 7i98 and 2 stepper motors with Axis UI. and like i said before, i can't do homing properly after doing it for the second time. when homing for the first time, the x and z axes are going back to the 0 position. but when i try to home again, only x axis goes to 0, the z axis doesn't move at all.

Problem:
Linuxcnc menus appear in a couple of menu categories.

Why:
The desktop files have multiple entries in the "Category key", which causes the issue above

Fix:
Download the 2 files attached
cd into the folder where the files are
This sets up the package manager to run when apt, apt-get or dpkg is run.
To run this manually, for the first time You may have to log out or not to see the changes in the menu.