Increase work coordinates precision

Catalin_RO · 28 Mar 2018, 06:57

Firmware 1.21 reports workplace coordinates with single decimal, and so does DWC. When doing precise workpiece alignments, better precision is needed. The screw driven WorkBee has 8mm per stepper revolution. With a 200 steps/rev stepper, that gives 25 steps/mm -> 0.04mm/step. With microstepping it gets well below 0.01mm/pulse.

Also it would be great if DWC would allow jogging with 0.01 step!

dc42 · 28 Mar 2018, 09:02

Added to the list!

dc42 · 30 Mar 2018, 19:34

When you say "Firmware 1.21 reports workplace coordinates with single decimal", which report are you referring to? G10 P# reports to 2dp already, but I can change that to 3dp if you like. The coordinates reported to DWC and by the M114 and M408 commands are to 3dp.

Catalin_RO · 30 Mar 2018, 20:16

Very simple to replicate… Power up machine and home. Then manually issue "G0X25.55Y34.56". DWC will announce as head position 25.6 for X and 34.6 for Y.

Realistically, 2 decimals are more than enough. Beyond that we are discussing of precision that comes only with really high price tags!

dc42 · 30 Mar 2018, 23:02

OK, it's a DWC issue. I suggest you raise it in the DWC wishlist section of the forum.

Danal · 31 Mar 2018, 00:56

This ultimately needs to be a "Pull" request in Github to the DWC repository. If you want a temporary fix for yourself, do the following:

Put the SD card from the Duet in a PC, Mac, or Linux box (whichever YOU like).
Find the /www/js directory.
Find the file dwc.js.gz
The exact next step depends on what tools you wish to use to deal with "G-Zip" compressed files. If you are on Windows, I'd recommend 7-Zip.
Open the dwc.js.gz file and find the dwc.js file inside it. Use a text editor that will not screw up Unix line ends to edit this file.
Find the exact string [c]toFixed(axisNames _== 'Z' ? 2 : 1)[/c]
Note: there will be other parentheses, etc. Be sure you change ONLY the above. As a double check, this will be around line 803 (as of R1.21).
Change it to [c]toFixed(2)[/c]
Save the edited dwc,js file. Put it back in the dwc.js.gz file, and put that file back in the SD card /www/js directory.

Return the card to the Duet, power up, and give it a try. You MAY have to do a "Ctrl-Shift-R" refresh, or otherwise clear your browser cache, to see the change. Also, if it just doesn't seem to change, somehow the dwc.js did not get back into the dwc.js.gz. This can be a bit awkward on windows._

Danal · 31 Mar 2018, 00:57

If that breaks anything, put the DWC files from github back on the card.