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For the tangential knife application, at the moment there is only a rotational value output available, wich
can be used in hal to connect to a motor or device.
There is no additional logic in the planner for the tangential knife.

I understand the concerns off DauntlessA regarding the use of the tangential knife when there is no additional
logic included.

I see basicly 2 solutions at the moment.

Solution 1 Basic :
Use the hal rotational value from the planner, connect the tangential motor in hal.
Then be sure your gcode uses ramp in path's so that the direction vector is always in the right direction.
In my perspective it's better to avoid straight z moves, but always a z move containing some xy changes, wich will
direct the tangential rotation in the path direction.

Solution 2 Advanched :
The planner has at the moment 4 build-in, you can call it "post processors". overview link
These are used to verify the planners behaviour at runtime. And they are used as fallback option and as a template layout.

We can easely add more post processors for special applications.

That's why the infrastructure in the planner is build up this way.
You just need to copy one off the current post processor .h header files, and edit it your way.

Then for example, we copy the "file_path_clothoid" to a new path algo: "file_path_clothoid_tangential_knife".

Then when doing the tpAddLine or tpAddCircle, we can add rotational start-, end values for a-axis, wich can be used for the
tangential knife device.

From the moment the a-axis has rotational tangential knife values.
It's part of the motion control system.

During the tpAddline & tpAddCircle we also look if a-axis has only motion, and xyz has motion or xyza has motion.
This makes difference in calculating speeds & trajectory length's.

So in fact a lot can be customized here. The planner has a clean modular infrastructure. And the oversight is not that hard to
follow.

I have build a cnc with tangential knife device years ago. It was sold to a shoe company to cut shoes from leather.



 

Yes you are doing it as PCW does it in man hm2_eth
Untested but you could try adding this to /etc/network/interfacesthen restart
You can check if enabled with

@Eneias_eringer,

To install it on different lcnc versions, you need to patch the original lcnc version first.
If you use a tool like :https://www.diffchecker.com/text-compare/
you can compare the files to path, with your current file. And see the difference between them.
This example shows how to patch the current lcnc git clone.

The path includes replacing 4 files, and needs at least 3 to be replaced or modified :

1. motion.c
2. tp.c
3. tp.h

In general : add the blue code after the existing green code.

1. motion.c
~Line 242 :

    tpMotData(emcmotStatus
             ,emcmotConfig
             );
    tpMotExtraData(emcmotCommand,
                   emcmot_hal_data
                   );

2. tp.c
~Line 64

static emcmot_status_t *emcmotStatus;
static emcmot_config_t *emcmotConfig;

emcmot_status_t *emcmotStatus;
emcmot_config_t *emcmotConfig;
emcmot_command_t *emcmotCommand;
emcmot_hal_data_t *emcmot_hal_data;

Note : in latest lcnc version some dev now used "static emcmot_status_t *emcmotStatus;".
We don't use that.

3. tp.h
~Line 20
#include "tcq.h"
#include "mot_priv.h"

~Line 85
               ,emcmot_config_t *
               );

// Forward decleration.
void tpMotExtraData(emcmot_command_t *
               ,emcmot_hal_data_t *
               );

Then i just tested a git clone and a patch by :

This worked.

When above is working, the last thing to do is install the scurve code.

We need google's ceres solver to be installed :sudo apt-get install libceres-dev
Then to install the scurve, you can invoke the ./build_cmake command from within the /cmake directory.
This then builds & installs the scurve component, clothoid lib, scurve lib etc.
 

I have 8 ST link V2 and they are all 128kb. How can I put the remora-rt1052-3.1.3.bin firmware on them when they are 350kb?

Doesn't work. The i226 uses the igc driver.
Neither igc.EEE=on or igc.EEE=off does work, entered just by chance.
As it turns out, eee is disabled by default on the new i226 card so all is good there.

Coalesce is set like thiswhich is perhaps how it always have been done. No need for any tx-usecs, that was the point. In fact, that is an error to add tx-usecs.

 

The flat control cable from the driver's controller has 16 pins, I shouldn't try it because I'm afraid that there will be some ``smoke signal''

the end of the shaft snaped off. i just pulled it apart to see what i could find. that's pretty odd

machinedude wrote:

 my x was a bit under powered, so this is reason to bump up a little since i can get a 3 Nm with the same frame and shaft size.

Great to see adoption of real engineering units in an imperial world! 

it did seem odd to me too but i did a quick search on google on mechanical failures with steppers and it said gears stripping? i never tore one apart before but i might on this one just to see the inside. when you spin it by hand it feels wrong. usually, you can feel the 1.8-degree full steps.it turns under power but it has no torque.

i got a bigger one this time of the same brand because i can have it later today. my x was a bit under powered, so this is reason to bump up a little since i can get a 3 Nm with the same frame and shaft size.

Thats unusual. Usually, they overheat and loose steps if you push them too far and eventually stop. There isn't anything to strip really. But the temperature could exceed the safe limit and melt the insulation in the windings. What happens if you swap stepper drives?

There is something to be said for using quality motors. Try Moons Industries who you are in US. 

 

I think there is more to consider when commanding a tangential knife. eg when do you lift it on a sharp corner? When do you have to overrun and reposition on a corner? I don't know anything about tangential knives but I am guessing the  motion for the knife that a supplier of mine uses to  cut my parts from rubber sheet is a bit different to a circular saw a stone mason uses.

One issue with external offsets is that you need to allocate a percentage of velocity and acceleration of the axis to the offsets. In some applications (eg plasma cutting) motion and offsets are mutually exclusive so you can allocate 100% of motion to the offsets by doubling the velocity and acceleration and using a offset ratio of 0.5

I've never experimented with anything but wouldn't you be able to to use joint.N.motor-pos-fb to align the knife?

well i have my first real issue with this build. the X axis stepper tapped out on me today. to be fair i was giving it a workout as usual
the funny part is i made a video and got thought the first one fine but only made it halfway through the next one

I'm pretty sure i stripped something out on the internal parts of the motor which is a first for me. i guess if you mess around with this stuff long enough you run into just about everything

i installed new version 2.9.4 and have problem, old 2.8.4 working well and no problems, now i have big problems, if i try open new G-code in ro linuxcnc "open code", then search file location windows go all time black screen and go back to login site. same than has boot all computer, why. same this doing if i try open code come black screen and then go back to open file location first 1-2 time and 3 time go main login screen and has closed all linuxcnc and computer.
but if i open g:code  not search rows what file and were have what open, only click open no problem and open code and run cnc good, but if open search rows were file have come all time black screen and go back to main login site again and all softwares has closed, 
sorry my english not can tell better what is problem. same if open linuxcnc sometime screen stay blinking wrong and any buttons not can use, need end linuxcnc software and open again then no blinkink screen and can use normal. blinking mean all pictures blink some have normal some black and display blink ad shake.