G53 - Wrong... direction?

Durahl · November 4, 2018, 5:12pm

As it just happens with every medium… Once you’ve worked long enough with the default stuff you long for less time-consuming methods which brings me to zeroing in the tool to your pieces Work Coordinate System.

Usually, I’d fix the piece to the waste board, set the travel distance to something between 50-100mm and start jogging away until I’d close in then finish it off in 5-10mm steps followed by 0.1-1mm ones.
Needless to say… It’s getting old REALLY fast which brings me to utilizing G53 - The Machines WCS.

Ideally, I’d be able to use the X-Carves silkscreen on the waste board and in UGS-P just enter G53 X150 Y70 Z40 for a 40mm tall piece who’s bottom front left corner touches the silkscreens X-15cm Y-7cm mark buuuuuut that’s apparently not how it works - At least not on my X-Carve as it’d come up with an error due to entering positive values.

To fix that not only would I have to enter it in negative space like G53 X-150 Y-70 Z-40 - But I’d ALSO have to use my machines total travel distance MINUS the desired value so in my machine’s case, with a total travel distance of a X760mm / Y805mm / Z110mm, it would have to be entered like G53 X-610 Y-735 Z-70 which is a bit of a P.i.t.A. aswell…

Soo… Does anyone know of a setting how it would be possible to address G53 coordinates naturally without all that weird… crap?

Durahl · November 4, 2018, 8:23pm

Yea, this I was aware of.

The way it behaves is also why it lends itself to be used for what I want to use it for - Send it to a location that can easily be read by the user just by looking at the machine you’re working with - If it just wouldn’t work in negative space.

Durahl · November 4, 2018, 9:05pm

Not sure… Worth a try I guess? Any suggestions where to start looking for?

While preparing an account on OpenBuilds.com to ask the Developer himself ( he appears to have opened a Q&A thread there ) or the Community I came across the GRBL 0.9 ( I’m on 1.1 ) Patch Notes mentioning:

Updated Homing Routine: Sets workspace volume in all negative space regardless of limit switch position. Common on pro CNCs. But, the behavior may be changed by a compile-time option though. Now tied directly into the main planner and stepper modules to reduce flash space and allow maximum speeds during seeking.

Which appears to be the cause of my grief… If there were some information on how this could be changed =)

NeilFerreri1 · November 5, 2018, 5:06am

Assuming this is what Larry’s compiled version changed (reference for those not afraid to compile their own):

github.com

gnea/grbl/blob/master/grbl/config.h#L129


      
          
          // Enables single axis homing commands. $HX, $HY, and $HZ for X, Y, and Z-axis homing. The full homing 
          // cycle is still invoked by the $H command. This is disabled by default. It's here only to address
          // users that need to switch between a two-axis and three-axis machine. This is actually very rare.
          // If you have a two-axis machine, DON'T USE THIS. Instead, just alter the homing cycle for two-axes.
          // #define HOMING_SINGLE_AXIS_COMMANDS // Default disabled. Uncomment to enable.
          
          // After homing, Grbl will set by default the entire machine space into negative space, as is typical
          // for professional CNC machines, regardless of where the limit switches are located. Uncomment this
          // define to force Grbl to always set the machine origin at the homed location despite switch orientation.
          // #define HOMING_FORCE_SET_ORIGIN // Uncomment to enable.
          
          // Number of blocks Grbl executes upon startup. These blocks are stored in EEPROM, where the size
          // and addresses are defined in settings.h. With the current settings, up to 2 startup blocks may
          // be stored and executed in order. These startup blocks would typically be used to set the g-code
          // parser state depending on user preferences.
          #define N_STARTUP_LINE 2 // Integer (1-2)
          
          // Number of floating decimal points printed by Grbl for certain value types. These settings are
          // determined by realistic and commonly observed values in CNC machines. For example, position
          // values cannot be less than 0.001mm or 0.0001in, because machines can not be physically more

Durahl · November 5, 2018, 11:22am

Hmm… I’ll be having a look at the provided HEX file first before digging any deeper into making my own one.

I’ll be reporting back with my findings on if this solved my problem - Thanks to both of you for taking the time!

Durahl · November 8, 2018, 10:47am

Yesterday I tried making use of the .HEX file provided by @LarryM but soon had to realize that I couldn’t find any reliable information on how to actually use it. From my understanding .HEX files appear to require a different software than the Arduino IDE that’s normally being used and the most suggested one ( Xloader? ) is kind of a hit/miss thing - Especially on Win10 where it doesn’t work?

Anyway… Picking up @NeilFerreri1’s post it appears that the same result could be achieved by downloading the most recent version of GRBL ( not the worst idea anyway as there appears to be a critical FIX ), edit the marked line ( 129 ) in config.h and then simply upload it to the X-Controller using the Arduino IDE like how it’s being described in the Inventables Support section?

Durahl · November 8, 2018, 5:34pm

What critical fix?

The ones mentioned in the GRBL releases section.

Your files date stamp appears to be ~4 months older than the latest release so it would make sense to go with the newer one including all sorts of fixes.

What are you looking for?

How to actually load a HEX onto the Controller without relying on Xloader as it appears not be doing its job on Win10.
Once an upload was started it only ever tells me it’s Uploading… without apparently finishing and freezing up.
Testing the X-Controller after that won’t reveal any change in behaviour when using G53… It still aborts the command for as long as it’s not written in negative space.

Windows 10 is crap.

I did not provide that information for an “opinion”.