One at a time setting in Cura

[zoev89 73]

If I print with multiple objects I usually use "All at once" setting Cura. But I was printing a small object and I only needed 6 of them so I could print with "One at a time" setting. Using "One at a time" offered much better print quality since the amount of retractions was reduced by a large factor. No inner model retractions. However while printing the 3th object the printer stalled before going to the 4th object. So it left a large blob of material at the top and the wall was melted in (so basically failing that part). So I inspected the gcode but could not find anything strange. Second time printing it happened again but I knew now the print will continue so it just ruined one object. Today I made some modifications of the printed object and printed 7 of them (in the knowledge that probably 1 will fail so I ended up with the 6 that I needed). This time it stalled at going from the 2nd to the 3th, however I was able to see what was happening it was heating the bed and just waiting until the right temperature was reached (1 degree delta) so basically it could happen each time going from 1 part to the other. Now isn't there a setting in Cura that can control this behavior. Like first remove the nozzle from the printed part then set the bed temperature again (since that is in the startup profile of the part) and then start the next part. By first moving the nozzle away and then set the bed temperature would allow the printer to halt to warm-up the bed if needed.

 

My bottom layer bed temperature is the same as for the rest just imaging what would happen if the bed temperature would be higher for the first layer...

I use an ultimaker original with a home made heated bed and used Cura 2.7.1 on ubuntu.

 

 

[yellowshark 153]

That is an interesting problem; I use "print one at a time" all the time and have never seen the problem you describe. I will assume you use an Ultimaker as you do not say otherwise; I do not use an Ultimaker. Also I use Repetier Host to control the printer and this allows me to override some of the gcode settings at any time during the print, including bed temp. ( come back to that in a moment). I had always thought that setting the bed temp. and waiting for the printer to arrive at that temp. was a one off initialisation step in the start gcode. What you are saying seems to suggest that Cura builds the gcode seeing each of the models on the bed as being a new print and so goes through this initialisation step for each model. I have never looked at the gcode for multiple models so I do not know if this is the case or not. No doubt one of the Cura programmers like @nallath could confirm one way or the other.

 

Can you control the bed temp. direct from your printer? You could set a lower temp. in Cura but override it which I am thinking would remove your problem.

[zoev89 73]

Even if you control the temperature from the printer the gcode contains the

M190 S60

for every model start so even if you change the temperature it would at the start of each model reset the temperature to the one in the gcode. The M190 code specifies set to temperature and wait....

Actually Cura should not put this part of the startup code in for each model but only for the first. Or move the a save location (home) and then start the new model with all its settings. But that is thinking in solutions and I might be wrong.

 

 

[yellowshark 153]

Sure but if you override and do the print at say 65 then the code will not need to wait for the printer to warm up to 60 on new model start; then just override to 65 again ready for the next model change. Not ideal maybe but at least a workaround for now. Best to note that what I am saying is an educated presumption because I have not had to do this myself.

[yellowshark 153]

Yes I agree with you, I see no good reason for Cura to do this. A subsequent model print will occur immediately following the previous model so no need to change anything. BUT of course there is the "issue" that if you use a warmer bed temp. for the 1st layer then there is a logic in what Cura is doing. Do you use the same bed temp. through the entire print? I do when I am printing "one at a time". If  you do not then maybe that is why it is happening to you.

 

My view is that as long as the initial temps are the same as the subsequent print temps then everything is as wanted at model change so there is no need for Cura to repeat the initialisation process.

[zoev89 73]

My print the bed temperature remains the same. 

Your hack to change to 65 for each model I guess will work but you do have to baby sit it. 

I would rather in that case remove the M190 commands (except the first one) from the gcode in an editor that would be less error prone...

 

Edited December 29, 2017 by zoev89

[Nuttavoot 0]

Is this problem solved ? I am having the same problem with Cura 3.2.

[nocturnalit 0]

I am chasing a solution for the exact same thing! It still does this behaviour in 3.6

 

At the moment I manually edit the gcode.

[PuterPro 0]

This is a bit of an old post, don't know if it's still a problem (we're up to Cura 4.6.1 currently) but it occurs to me that this can be easily solved with the Post Processing Plugin. There's a setting in there that allows you to search and replace in the G-Code, so you could use it to remove the extra M190 commands.

 

Note that I think this would remove the FIRST M190, obviously not a good thing ... 🙂 But you could fix that by adding another command to the post processing - ChangeAtZ. Put it AFTER the search and replace command, change "Height" to "Layers", choose Layer 1, then set your desired print temp. Voila, you have one M190 command, starting at layer 1.

 

Now, I haven't tried this, never been a problem for me, just offering a possible workaround ... Don't know what this would do to any "Initial Printing Temp" or "Final Printing Temp", I suspect it would strip those too.

If you can live with one temp for the whole print, this might be a solution.

[ietz 0]

I just faced the same problem and threw together a quick post-processing script that removes any redundant "Set Bed Temperature" and "Wait for Bed Temperature" commands: RemoveReheat.py

Just save the py file in your Cura scripts Folder (on Windows %AppData%/cura/<version>/scripts), restart Cura, and enable the "Remove Reheat" by going to Extensions -> Post-Processing -> Modify G-Code -> Add a script.

The script removes the waits only if the target bed temp did not change.