Jerk Limits Using Incorrect Units for RepRapFirmware

[bradvaughan]

Version

2.3.56.8

Operating system type + version

Windows 10 Pro

Behavior

The "Jerk limits" in the "Machine limits" section on the "Printer Settings" tab indicates the units are in "mm/s". However, RepRapFirmware uses mm/min for this setting. This is an issue for both the time estimates as well as the "Safeguard" and "limit" options.

The resulting M566 command in the generate G-code simply copies the value from the screen, so it's off by a factor of 60x. Thankfully, this is in the direction of being slower than intended, but a bug nonetheless.

Additionally, this causes issues for the time estimates, because you need to put in the correct mm/min values to get the appropriate G-code, so the time estimates end up artificially low. Again, this isn't a huge issue given jerk's relatively minor impact on overall print time in comparison to feed rates and acceleration.

Is this a new feature request?
No

Project File (.3MF) where problem occurs

N/A. It occurs on all G-Code exports for RepRapFirmware that I've tried.

[supermerill]

I though I made it, but maybe I forgot to merge...
#632 #440

[supermerill]

Additionally, this causes issues for the time estimates, because you need to put in the correct mm/min values to get the appropriate G-code, so the time estimates end up artificially low. Again, this isn't a huge issue given jerk's relatively minor impact on overall print time in comparison to feed rates and acceleration.

That shouldn't happens, it's converted from mm/min to mm/sec. Maybe it's the feedrate unit that is creating some problems...
Can you post your project where the time estimate is problematicaly slow ?

[bradvaughan]

Will do this evening. I appreciate the responsiveness.

…

On Mon, Aug 23, 2021, 5:53 AM Merill ***@***.***> wrote: Additionally, this causes issues for the time estimates, because you need to put in the correct mm/min values to get the appropriate G-code, so the time estimates end up artificially low. Again, this isn't a huge issue given jerk's relatively minor impact on overall print time in comparison to feed rates and acceleration. That shouldn't happens, it's converted from mm/min to mm/sec. Maybe it's the feedrate unit that is creating some problems... Can you post your project where the time estimate is problematicaly slow ? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1500 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANNCBMPPGUUNCPPXTYUFUWTT6ILAVANCNFSM5CTS3A4Q> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .

[bradvaughan]

For me, the values are copied directly and not being converted from mm/s to mm/min. [image: image.png] [image: image.png]

…

On Mon, Aug 23, 2021 at 5:56 AM Brad Vaughan ***@***.***> wrote: Will do this evening. I appreciate the responsiveness. On Mon, Aug 23, 2021, 5:53 AM Merill ***@***.***> wrote: > Additionally, this causes issues for the time estimates, because you need > to put in the correct mm/min values to get the appropriate G-code, so the > time estimates end up artificially low. Again, this isn't a huge issue > given jerk's relatively minor impact on overall print time in comparison to > feed rates and acceleration. > > That shouldn't happens, it's converted from mm/min to mm/sec. Maybe it's > the feedrate unit that is creating some problems... > Can you post your project where the time estimate is problematicaly slow ? > > — > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub > <#1500 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ANNCBMPPGUUNCPPXTYUFUWTT6ILAVANCNFSM5CTS3A4Q> > . > Triage notifications on the go with GitHub Mobile for iOS > <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> > or Android > <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> > . >

[supermerill]

There's a problem? I don't see any image and I can't download your project file.

[bradvaughan]

I tried to do it via email. I'll do it directly on GitHub tonight.

…

On Tue, Aug 24, 2021, 12:52 PM Merill ***@***.***> wrote: I don't see any image and I can't download your project file. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1500 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANNCBMN6TIBR24ZEVD3P23DT6PE3XANCNFSM5CTS3A4Q> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email> .

[bradvaughan]

M566 X1200.00 Y1200.00 Z1200.00 E40.00 ; sets the jerk limits, mm/sec

3DBenchy-jerk-test.zip