dayaan
Posts: 3
Joined: Sat May 12, 2018 3:12 pm

filament length calculation wrong with retraction

Sat May 12, 2018 3:14 pm

When using retraction the filament length calculation adds that retraction length per line each time, resulting in wildly overestimated lengths with long retraction settings.. can be tested easily by disabling and enabling retraction or changing the retraction length.

User avatar
DarthRevan
Posts: 466
Joined: Wed Feb 18, 2015 8:29 am

Re: filament length calculation wrong with retraction

Tue May 15, 2018 9:46 am

There are a lot of options for retractions. Can you post your factory file so we can look at the exact setup that may be causing such reporting of the extruded length? :geek:

dayaan
Posts: 3
Joined: Sat May 12, 2018 3:12 pm

Re: filament length calculation wrong with retraction

Tue May 15, 2018 10:02 am

there is no point in me sending you files.. copyright.. just put any 3d object (preferably something that needs a lot of retraction) to print and test with enabling retraction with different retraction lengths.. the retraction lengths get ADDED to the calculated length of total filament used instead of being ignored.. retraction itself does not make a difference in filament used (NOT talking about extra distances(+/-mm) or coasting (-mm))..

just try the SAME print with retraction ON (let's say 3mm - the more you put, the more it ADDs up) and OFF (or put it on 0mm).. as i've said before.. no extra distances or coasting.. wiping doesn't matter (does not affect filament lengths)..

horst.w
Posts: 797
Joined: Fri Oct 17, 2014 5:00 pm

Re: filament length calculation wrong with retraction

Tue May 15, 2018 3:51 pm

Sorry, but my example shows me the contrary:

Without retracts 2271.9 mm

With retracts 2255.7 mm

I print 2 identical objects with really a lot of retracts for each and additional the changes of position of the printhead between them.
I think my difference is resulting by the setting of negativ restart of -0.13 mm and indeed for the whole print the extruder works a little bit less than printing without retracts.

The difference of 16 mm is not worthwhile to speak about.

H.

User avatar
DarthRevan
Posts: 466
Joined: Wed Feb 18, 2015 8:29 am

Re: filament length calculation wrong with retraction

Tue May 15, 2018 4:15 pm

horst.w wrote:
Tue May 15, 2018 3:51 pm
Sorry, but my example shows me the contrary:

Without retracts 2271.9 mm

With retracts 2255.7 mm

I print 2 identical objects with really a lot of retracts for each and additional the changes of position of the printhead between them.
I think my difference is resulting by the setting of negativ restart of -0.13 mm and indeed for the whole print the extruder works a little bit less than printing without retracts.

The difference of 16 mm is not worthwhile to speak about.

H.

Good point! Negative extra restart would cause this type of reporting as the retracted amount and the primed amount in this case wouldn't be equal and would therefore shorten the total amount extruded. Just how positive extra restart would increase the amount of filament extruded and factored into the total for the print.

Return to “Troubleshooting and Bug Reports”