Dumb question about configuration

I have duet electronics which I inherited with my RepRapPro Mendel 3 kit. I'm toying with the idea of building another printer, possibly corexy and it will most definitely use Duet electronics with dc42s excellent firmware and chrisshams excellent web interface. Now I've changed various things in my config.g such as tool definitions, extruder steps per mm etc and I note that there are also settings for reversing motor directions, using a modulated bed probe, setting motor currents, maximum speeds and accelerations etc. But for the life of me, I can't find anything anywhere which defines steps per mm for x y and z axes. The chances are high that my "TBA" printer will have different pulley sizes or threaded rods so how would I go about telling Duet what these are?

Use the M92 command in config.g to set the steps/mm. See [reprap.org].

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

All of the settings for your duet are in config.g in the form of various g codes. Have a look at the file and then compare what you see there to the wiki page on g code commands here. You can figure out what each code does and learn a lot. Of course Dave is correct with m92, but you may want to look into what some other stuff is as well, might discover something useful you didn't even know exists for your new machine.

Yes, for RRF specific G-Codes, here : [reprap.org]

Edited 1 time(s). Last edit at 04/29/2016 04:43PM by PRZ.

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

Quote
Koko76
All of the settings for your duet are in config.g in the form of various g codes. Have a look at the file and then compare what you see there to the wiki page on g code commands here. You can figure out what each code does and learn a lot. Of course Dave is correct with m92, but you may want to look into what some other stuff is as well, might discover something useful you didn't even know exists for your new machine.

Yes, I've spent a lot of time looking at the config.g file and I understand what all the commands are and what they do. So that's what's confusing me. There is nothing in my config.g that defines the steps per mm for the x,y and z motors, only the extruders (which I've calibrated by the way). So not all the settings for my duet are in the config.g. The settings for the x,y and z steps per mm must be elsewhere.

My guess is that RepRapPro didn't want anyone playing around with these so they are hard coded somewhere??

RepRapPro wrote the original version of RepRapFirmware, so the default steps/mm is correct for the MXL belts and pulleys that their kits used

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
deckingman

My guess is that RepRapPro didn't want anyone playing around with these so they are hard coded somewhere??

RRP had no interest in such protection, and did nothing but encourage people to play around with the settings.

Just looked in the config.g for my Mendel 3 and your correct whilst there is a M92 in there for setting the extruder steps per MM, but none for the XYZ axes, which leads me to conclude that there is probably a default value in the firmware, and the Mendel 3 axes configuration matches that default value.... since the Mendel 3 axes configuration is one of the most common configuration there is for a reprap this would make sense.

The M92 just serves to overwrite the default values, you can test this theory yourself by adding a M92 to change the steps per mm value and see if it makes a difference

Edited 1 time(s). Last edit at 04/30/2016 05:11AM by bgkdavis.

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis

Quote
deckingman

My guess is that RepRapPro didn't want anyone playing around with these so they are hard coded somewhere??

RRP had no interest in such protection, and did nothing but encourage people to play around with the settings.

Just looked in the config.g for my Mendel 3 and your correct whilst there is a M92 in there for setting the extruder steps per MM, but none for the XYZ axes, which leads me to conclude that there is probably a default value in the firmware, and the Mendel 3 axes configuration matches that default value.... since the Mendel 3 axes configuration is one of the most common configuration there is for a reprap this would make sense.

The M92 just serves to overwrite the default values, you can test this theory yourself by adding a M92 to change the steps per mm value and see if it makes a difference

Yes I'm sure M92 will work because I've done it for the extruder motors. I understand that M92 will overwrite the default values (sorry "hard coded" was a bad expression to use). There must also be default values for other stuff such as PID terms for heaters. So is there a list of what these default values are? It seems pointless to put gcode commands in config.g if all they do is mirror what is already set. Which is what I was trying to say in my original post but obviously didn't word it well.

Quote
dc42
RepRapPro wrote the original version of RepRapFirmware, so the default steps/mm is correct for the MXL belts and pulleys that their kits used

Ah, now it makes sense - wish I'd read this before I posted the last comment. So, is there any way of finding out what the default values are, as it seems pointless adding gcode commands to config.G if all they do is mirror what is set by default?

Quote
deckingman

Quote
dc42
RepRapPro wrote the original version of RepRapFirmware, so the default steps/mm is correct for the MXL belts and pulleys that their kits used

Ah, now it makes sense - wish I'd read this before I posted the last comment. So, is there any way of finding out what the default values are, as it seems pointless adding gcode commands to config.G if all they do is mirror what is set by default?

Two ways to find the default values:

1. Look in the firmware source code. Most default values are defined in either Configuration.h or Platform.h.

2. For most parameters, you can find the existing values by entering the appropriate command without the parameter to set the value. For example, to find the default steps/mm, boot up a Duet with no M92 command in its config.g file, then run M92.

Edited 1 time(s). Last edit at 04/30/2016 07:19AM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
deckingman
It seems pointless to put gcode commands in config.g if all they do is mirror what is already set.

Absolutely not pointless, quite the opposite, its good practice, especially if you regularly update firmware....you got no idea what DC42 will fat finger in the next firmware release.

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
dc42

Quote
deckingman

Quote
dc42
RepRapPro wrote the original version of RepRapFirmware, so the default steps/mm is correct for the MXL belts and pulleys that their kits used

Ah, now it makes sense - wish I'd read this before I posted the last comment. So, is there any way of finding out what the default values are, as it seems pointless adding gcode commands to config.G if all they do is mirror what is set by default?

Two ways to find the default values:

1. Look in the firmware source code. Most default values are defined in either Configuration.h or Platform.h.

2. For most parameters, you can find the existing values by entering the appropriate command without the parameter to set the value. For example, to find the default steps/mm, boot up a Duet with no M92 command in its config.g file, then run M92.

Thankyou

Most defaults values added on the wiki here : [reprap.org]

---

Pierre

- Safety [reprap.org]
- Embedded help system for Duet and RepRap Firmware [forums.reprap.org]
- Enclosed delta printers Lily [rouzeau.net] and Lily Big [rouzeau.net]
- OpenScad delta printer simulator [github.com]
- 3D printing on my site [www.rouzeau.net]

Quote
PRZ
Most defaults values added on the wiki here : [reprap.org]

Brilliant !! Thank you.