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Hi Friends, 

I am pulling my hair out trying to determine how many steps it take for my angular C axis to make one full revolution. I recently had to redesign the tangential cutting head so while I had it off the machine I wanted to tune it as much as possible with the tools i had available  (scale, min max jog speed, etc) 

So i set out to determine how many steps it would take the motor to rotate the output shaft one full revolution. After a few days of doing what I thought was simple calculations to little to no success I tried to go bottom up. That is, hard coding the number of steps and adjusting based on behavior. this took like 5 minutes to get it pretty close.. However, its not perfect and I'd like it to be close i don't understand why it is the number it is. I don't think i understand the 'Pulse/rev' table on the driver. 

The bottom up number i got for steps per revolution was around 540. 

Current settings:
Pulse/rev (dip switches) 1600
Motor Step Angle 1.8
Pulley Ratio :3.12

No matter how i combine those numbers i cannot seem to get anywhere close to the 540, the number that actually produces somewhat close to a full revolution. 

Any help or explanation is greatly appreciated. My end goal is a precise calculated steps per revolution. 

Ps. i am ignoring that this is a servo motor and capable of closed loop control, not sure if this logic holds but i would like it the be as close to correct as possible then use the PID controls to correct error and not lean on it due to sloppy setup work. 

If its just a flash issue, ( normal Ethernet comms  are reliable )
It may possibly be a a compatibility issue or perhaps signal
integrity or some other flash EEPROM connection issue.

In all honesty if the kernel gives no issues I wouldn't bother upgrading, from memory there isn't much of a difference in performance.

The first issue I run into is that my gear track is 5 TPI The shaft diameter to the motor is 18mm does anyone build gears with metric bores and imperial gear pitch? buy a 5/8 bore pinion chuck it up in the lathe and bore it out to 18mm? hand file to broach out the keyway? a 20 T pinion should get me to about 600 ipm if my calculations are correct. which is honestly to fast but I am worried a 10t will not have enough contact and skip or slop.

I have a spindle that has motor pulley belt pulley
after has a geartrain with 2 positions-speeds.
I want to mount encoder to second pulley shaft before geartrain.
Iam confused how to set ini file values
max_speed min_speed encoder_scale output_scale etc


 

  This is the very end of the message

 Hi, I updated from Linux CNC 2.8.2 to 2.9 and get the following errors when I try and open Linux CNC      

Can anyone help Please
Thanks

The IP address is a 32 bit number internally, so you should be able to pass it as an unsigned long parameter. you would need to convert 192.168.1.1 to 4 bytes in hex, then use setp

I could need a little help. I compiled my kinematics with halcompile --install. And i used the vismach xyzbc-trt-kins (switchkins) demo. I tried to replace the original Kinematics with my custom kinematics and after some commenting out i got this error message. Would be glad for some input to guide me in the right direction.

I continued a little bit and now its this:

Note: Using POSIX realtime
motmod: dlopen: /usr/lib/linuxcnc/modules/motmod.so: undefined symbol: kinematicsSwitch
././xyzbc-trt_cmds.hal:38: waitpid failed /usr/bin/rtapi_app motmod
././xyzbc-trt_cmds.hal:38: /usr/bin/rtapi_app exited without becoming ready
././xyzbc-trt_cmds.hal:38: insmod for motmod failed, returned -1
20961
Stopping realtime threads
Unloading hal components
Note: Using POSIX realtime

Because there are no cutting forces, there is no need for closed loop motors on a plasma machine. The only time I saw missed steps was when the motors overheated which is a result of motor voltage too high and/or velocity or accelleration is too high when deliberately pushing the limits...

Raspberry Pi 4 Model B Rev 1.2
Mesa 7c81
Debian GNU/Linux 12 (bookworm) 6.1.54-rt15 #1_RT Fri Nov 17 17:02:27 AEST 2023 aarch64

I installed LinuxCNC 2.9.3 from the linuxcnc ISO image a couple of years ago, and upgraded to 2.9.4 yesterday by:
$ sudo apt update  && sudo apt full-upgrade

I now have:
rick@raspi4:~$ dpkg -l | grep linux-image
ii  linux-image-bcm2711-rpi-4            6.1.54-rt15-1                           arm64        Linux kernel, version 6.1.54-rt15
rick@raspi4:~$ dpkg -l | grep linuxcnc
ii  linuxcnc-doc-en                      1:2.9.4                                 all          motion controller for CNC machines and robots (English documentation)
ii  linuxcnc-uspace                      1:2.9.4                                 arm64        motion controller for CNC machines and robots
ii  linuxcnc-uspace-dev                  1:2.9.4                                 arm64        PC based motion controller for real-time Linux

rick@raspi4:~$ uname -a
Linux raspi4 6.1.54-rt15 #1 SMP PREEMPT_RT Fri Nov 17 17:02:27 AEST 2023 aarch64 GNU/Linux

Is there a newer RT kernel then the one from 2023 ?
If so, how can I upgrade the kernel without having to reload the entire system from the latest ISO image ?

TIA,
Rick
 

Hi Andy,
Thanks for the response. One idea I was playing around with was making a raw-module API for the HM2 driver where user-provided HAL components can just hook into that to get HM2 module lifecycle notifications and make raw reads and writes to the FPGA (see  hostmot2-module.h ).

Unfortunately I haven't had time to complete that as I eventually went with just creating a HAL component that pokes the GPIO lines which were adequate for my needs. As for the device I'm trying to control, it's for the Emco Concept Mill55 ACC backplane that has a bus-multiplexor device to read and write slow I/O signals. I'm trying to do a minimal conversion where only the (old, broken) computer is replaced with a 7i80HDT, that interfaces directly with the ACC backplane board. Eventually I'll try to do a write-up of my conversion, but for now, I'm still trying to get everything working.
 

I loaded the table up with as much baking soda as we could buy from walgreens. Man did they give me a funny look when I bought them out of baking soda.... My freind came by and dropped off the motors all brand new. He says next month they may have some larger brother motors coming in close to a 1000w he thinks. These ones are 120w with a 20-1 gear ratio. Brushless stepper motors. What do you guys think, do you think its enough to power the gantry two of them for the Y direction? or should I hold off and wait for the larger motors or buy some new ones. I dont need crazy rapid speeds but being able to cut 16 g would be nice. 

         

Here are some of my designs do you have any recomendations?I am planing to use 7i96,Kind regards

Hi All,
Since some time I'm the proud owner of a 1994 Fadal VMC15, still in working condition.
However as it's equipped with the Baldor SWEO drive, known to die at a certain moment in time, with that same risk on the other electronics, I want to be prepared for a retrofit.
Searching this forum, I found lots of bits & pieces but not a complete 'how to retrofit guide' yet, also due so many different options / choices available for a retrofit.

My Fadal is currently equipped with DC servo motors and "Glentek GA377F-5" analog DC servo drives, the 7500RPM spindel and Baldor SWEO spindel drive and the 21 tools umbrella tool changer.
My initial plan is to keep the DC servo setup including the original resolvers and drives, replace the Baldor SWO by a modern VFD and hook up the machine to MESA cards under LinuxCNC control.

According to some experts, active at this forum, such setup should be very well doable as others did this trick already in the past.
Therefore I'm looking for advice on which MESA cards make best sense, how to hookup the servo's, how to deal with the VFD replacement and finally the tool changer setup.

Your thoughts, ideas and advice are deeply appreciated.

Thanks