Slow down before endstop?

fcwilt

@thekm said in Slow down before endstop?:

@fcwilt I get that once you know where the machine is, you can tell it basically anything about the machine and workspace from there... but if it's triggering at 275... how does it happily cut a job at 285 and have the sensors work as endstops by leaving the machine alone unless it goes to cross 300?... this is what I mean about losing that area of workspace. If something goes wrong, bad feeds and speeds loses steps, endstops should shut it all down at 300.

Endstops don't work for normal G1 moves as used during printing.

I know of nothing in the current firmware that can do what you mentioned - short of using a trigger to activate an external relay to kill power.

But I now understand what you were talking about in earlier posts.

Thanks.

Frederick

theKM

@fcwilt ...at the moment I just use duet's ability to reset with an endstop hit, which stops the spindle and everything else. But is also why endstop hits are so annoying at the moment and would be nice to have the machine measure itself out when turned on (as it will prevent moves outside its bounds, etc etc)

fcwilt

@thekm said in Slow down before endstop?:

@fcwilt ...at the moment I just use duet's ability to reset with an endstop hit,

How is that done?

Thanks.

Frederick

theKM

@fcwilt CNC mode?... my endstop line is just "M574 X1 Y1 A1 B1 S1"... but there's no doubt that it reboots

fcwilt

@thekm said in Slow down before endstop?:

@fcwilt CNC mode?... my endstop line is just "M574 X1 Y1 A1 B1 S1"... but there's no doubt that it reboots

Thanks.

CNC mode must work differently but I see nothing in the M574 docs that allows for your syntax or suggests that the behavior changes in CNC mode.

Do you have a link to some CNC specific docs?

Perhaps I am just missing something.

Frederick

Phaedrux

@thekm said in Slow down before endstop?:

@fcwilt CNC mode?... my endstop line is just "M574 X1 Y1 A1 B1 S1"... but there's no doubt that it reboots

You must still be using RRF2?

theKM

@phaedrux I was... and just updated to RRF3.3 to try the probe thing mentioned above... and now I am quite sad, as now the spindle control isn't working... so now I have to wade through all the nonsense of figuring it all out again for the new firmware....

...backwards compatibility, it used to be a thing

¯\_ (ツ)_/¯

fcwilt

@thekm said in Slow down before endstop?:

@phaedrux I was... and just updated to RRF3.3 to try the probe thing mentioned above... and now I am quite sad, as now the spindle control isn't working... so now I have to wade through all the nonsense of figuring it all out again for the new firmware....

...backwards compatibility, it used to be a thing

¯\_ (ツ)_/¯

Well your v2 vs my v3 clarifies things.

If you figure out how to get endstops to act the way you want please let us know as I would like know as well.

Frederick

theKM

@fcwilt I have a spare duet that I'm about to play with the probe and a breadboard to see if a voltage divider will do what I want

fcwilt

@thekm said in Slow down before endstop?:

@fcwilt I have a spare duet that I'm about to play with the probe and a breadboard to see if a voltage divider will do what I want

Interesting. Hope it works.

Frederick

Phaedrux

@thekm said in Slow down before endstop?:

the nonsense of figuring it all out again for the new firmware....

This is the usual spiel I give for users doing the upgrade.

If you still have access to DWC. Upload these 3 zip files, one at a time in the system tab. Don't extract them first. Reboot after each. Use M115 in the gcode console to verify the firmware has been applied.
https://github.com/Duet3D/RepRapFirmware/releases/download/2.05.1/Duet2Firmware-2.05.1.zip
https://github.com/Duet3D/RepRapFirmware/releases/download/3.0/Duet2and3Firmware-3.0.zip
https://github.com/Duet3D/RepRapFirmware/releases/download/3.3/Duet2and3Firmware-3.3.zip
That will get your firmware and DWC up to date.

You can see the change logs here:
https://github.com/Duet3D/RepRapFirmware/wiki/Changelog-RRF-3.x

For your config, might be a good idea to run through the configurator tool and generate a fresh set for RRF3.
https://configtool.reprapfirmware.org/Start

Backup your existing config files in the sys folder in case you want to switch back to RRF2. It’s easy to switch back and forth, just upload the zip file for the version you want and then upload your config files.

These documents will come in handy during the conversion.
https://duet3d.dozuki.com/Wiki/RepRapFirmware_3_overview
https://duet3d.dozuki.com/Wiki/Gcode

theKM

@phaedrux the firmware is updated, got through that. The machine moves, spindle and such isn't working, which went through a huge change in RRF it seems... spindles and external stepper drivers aren't covered in the config tool, I just have to go through it all line by line again. There's scattered config examples around, I should be able to get through it.

Phaedrux

There is this https://duet3d.dozuki.com/Wiki/Configuring_RepRapFirmware_for_a_CNC_machine but I'm not sure how up to date it is. If you have any suggestions on improving that page while you go through it, please let me know and I can update it. I'm not a CNC user myself, so my understanding is limited.

theKM

@fcwilt ...voltage divider works in so much as I get the 500 and 1000 levels through the zprobe input. Next is making the machine move and see what it does with G38.2

theKM

@sinned6915

So I've tried to chase down what straight probing can do for me...

I made a setup with a breadboard to emulate the analog signal, and confirmed that with buttons I could trigger a value of around 515, and 1000 (confirmed in DWC probe interface)... to correspond with the docco of what the IR probe does. Set the probe value with G31, also verified in the UI.

Regardless of what I send through 32.8, it only ever moves at the second feedrate from 558, nothing I tried got it to move at the initial faster rate.

The move itself accelerates and decelerates if not interrupted, and the stop is still a hard stop (it's only moving at the second slower feedrate, so I guess that's expected).

There is an ominous line in the gcode docco:

"When doing a plain G30 command, an additional probe will be done using the first speed to establish the approximate bed position, before one or more additional probes are done using the second speed. The first speed will not be used when probing at a defined point or when mesh bed probing.".

I've tried to find any config examples of something I may have missed to get it to honor the initial feedrate, but, not finding any.

M558 P1 C"zprobe.in" H0 F10000:300 T500
G31 P500 X0 Y0 Z0

; following line is actually pretty handy
G38.2 X{move.axes[0].userPosition-25}

Phaedrux

@thekm said in Slow down before endstop?:

There is an ominous line in the gcode docco:

"When doing a plain G30 command, an additional probe will be done using the first speed to establish the approximate bed position, before one or more additional probes are done using the second speed. The first speed will not be used when probing at a defined point or when mesh bed probing.".

This refers to using the A parameter to do multiple probings. That's when the second probe speed is used.

theKM

@phaedrux ...I don't know what's left to try then, I'm not setting any "A" parameter anywhere and it's only ever moving at the slower feedrate.

The M558 and G31 lines above configure the probe, when the G38.2 runs the probe input certainly stops the move, but nothing I've tried gets the probe to move at the initial 1000 to allow it to slow to the second feedrate.

M558's P1 sets the analog input, and G31 sets that threshold, and it does indeed trigger based on G31's P value

Phaedrux

You're trying to use two different features together.

The M558 P1 analog input allows for the slow down as part of the ir probe functionality. I'm not sure if that will actually work with a non-ir probe at all.

And defining the two speed probing is only used when A is set. If you set A2, the first probe would be fast, it would then trigger, back off to the dive height, and then probe again at the slower speed.

theKM

@phaedrux

I'm not sure if that will actually work with a non-ir probe at all.

...the IR probe just sets a voltage on the input pin for however close it thinks something is. I've replicated the voltage with a couple of resistors as a voltage divider, the controller thinks it's an IR probe. The DWC UI says its emulation of analog probing is working fine.

And defining the two speed probing is only used when A is set. If you set A2, the first probe would be fast, it would then trigger, back off to the dive height, and then probe again at the slower speed.

Yup, certainly seems that way.

Annnnnyways... would be nice if there was an option for G1 to receive an interrupt in order to slow down ahead of an end stop.

fcwilt

@thekm said in Slow down before endstop?:

And defining the two speed probing is only used when A is set. If you set A2, the first probe would be fast, it would then trigger, back off to the dive height, and then probe again at the slower speed.

So even having two speeds doesn't solve the problem of the abrupt stop?

Frederick