Print speed, hot end air flow direction, unstopped bed heating June 14, 2014 04:11PM |
Registered: 8 years ago Posts: 21 |
Re: Print speed, hot end air flow direction, unstopped bed heating June 14, 2014 04:38PM |
Registered: 9 years ago Posts: 14,639 |
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paflviet
Print speed : using Pronterface, whenever I load a G-code file I can read in the output log a pessimist estimation of the print duration. The actual duration is always much longer than the estimation by a factor from 2 to 5 (20mn in place of 11mn, 2h45 in place of 45mn, ...). I've tried changing the speeds in Slic3r and regenerating the G-code file from the STL file, the speed is always the same. What can I do to change the printing speed ?
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paflviet
Hot end air flow direction : which direction should the air flow ? toward the hot end (blowing) or away from the hot end (aspiring) ? Mine is aspiring, I find it strange as I've often read about the importance of hot end cooling and blowing seems to me more efficient. I've checked a few times the wiring, it seems ok. Of course I can try to wire it reversed but I'd prefer an advice before changing it.
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paflviet
Bed heating : the post-printing commands automatically added by Slic3r to the G-code file (G1... for parking, M1 for halting) seems there to stop the hot end and bed heaters. My hot end actually stops heating, but not the bed. Is this normal ? probably not ;-) I've tried with different post-commands (M104 S0 and M140 S0), same issue no matter the order of the commands (M104 then M140 or M140 then M104).
Re: Print speed, hot end air flow direction, unstopped bed heating June 14, 2014 05:38PM |
Registered: 8 years ago Posts: 21 |
My real concern is about changing the printing speed : as long as I understand the print time is directly related to the speed for print moves, and the speed influences the print quality as a side effect.Quote
dc42
I don't know what's happening there because I use the web interface to control the printer instead. The web interface provides 3 different estimates of print end time, or 4 if you use my variant of the firmware and web interface. The last one (based on filament consumption) is usually quite accurate.
For the moment, I'm learning how my printer works before beginning to modify it, I keep your suggestion for the fan inlet duct replacement somewhere in my mind.Quote
dc42
There is a lot of backwash from the fan unless you fit an inlet duct, so it is easy to think the fan is blowing the wrong way. If you search this forum, you will find a number of designs for fan inlet ducts. The one I use is here [github.com]. It's designed for screw fixing, so you need a couple of long (50mm AFAIR) M3 countersunk screws to fit it.
Ok, I've found the M190 command, it's the bed temperature setting at the very beginning of the G-code file generated by Slic3r. I'll try with your M190 S0 command.Quote
dc42
That's probably because you (or slic3r) are using the M190 command somewhere to set the bed temperature, and there is a bug in the firmware. A workaround is to put M190 S0 before the M1 command.
Re: Print speed, hot end air flow direction, unstopped bed heating June 15, 2014 06:34AM |
Registered: 9 years ago Posts: 105 |
Re: Print speed, hot end air flow direction, unstopped bed heating June 15, 2014 03:06PM |
Registered: 9 years ago Posts: 377 |
Re: Print speed, hot end air flow direction, unstopped bed heating June 15, 2014 03:50PM |
Registered: 9 years ago Posts: 14,639 |
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paflviet
Ok, I've found the M190 command, it's the bed temperature setting at the very beginning of the G-code file generated by Slic3r. I'll try with your M190 S0 command.Quote
dc42
That's probably because you (or slic3r) are using the M190 command somewhere to set the bed temperature, and there is a bug in the firmware. A workaround is to put M190 S0 before the M1 command.
Re: Print speed, hot end air flow direction, unstopped bed heating June 16, 2014 09:29AM |
Registered: 9 years ago Posts: 2,472 |
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paflviet
My real concern is about changing the printing speed : as long as I understand the print time is directly related to the speed for print moves, and the speed influences the print quality as a side effect.
Slic3r has a print tab with a speed sub-tab, I've tried to modify the settings one after another to check carefully (and learn) which parameter had which effect, nothing changed. I also read quite all the topics from this forum, every topic about speed directed me to this Print/Speed tab.
I did a diff on different versions of the generated G-code file (same STL source file, only one parameter changed at a time, ...), they seem to incorporate various speed settings but the print time remains constant no matter the change I test.
Re: Print speed, hot end air flow direction, unstopped bed heating June 16, 2014 05:44PM |
Registered: 8 years ago Posts: 21 |
You were right, inserting a M190 S0 before M1 solved my issue.Quote
dc42
That's probably because you (or slic3r) are using the M190 command somewhere to set the bed temperature, and there is a bug in the firmware. A workaround is to put M190 S0 before the M1 command.
Actually I'm a Unix system engineer and used to these procedures, changing things slowly and one after anotherQuote
MrCrispi
Welcome to the forum and don't worry - we've all been on the journey you are on and it will come right. My advice would be to try and get some basic prints working (like snowman and coathook) using standard settings before adjusting too much - that can come later. In case it is useful to you, I have attached my standard Slic3r setting which you can just import (one each for printer, print and filament - these are based on all the good advice I got when I started and give me rock-solid results every time - I go back to these whenever I get in a tangle and I know for certain that they work fine with @DC's firmware and web interface. They will give you a baseline that you can rely on the for the slicing, allowing you to concentrate on what the printer itself is doing- good luck and stick with it
I checked once again my wiring and it seemed right. As I always tested the air flow with the feelings on my handQuote
jstck
Regarding the fan, there is always one correct direction for it to rotate. The blades are slightly curved, and the "inside" of that curve is always in the direction of the airflow. Some fans have an arrow on the housing pointing in the airflow direction as well (and sometimes also one showing the direction of rotation).
If it is turning the other way it is probably wired wrong, and having like that will make it significantly less efficient in moving air. There are aerodynamical reasons for having the blades curved like that, and having them go the other way is rather counterproductive.
I checked your 0.65g-dc42 firmware and posted a message in that other thread after a lot of tests. Bad news, I found some issues. Or I've totally missed something, do not hesitate to show me where I'm wrong.Quote
dc42
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paflviet
Ok, I've found the M190 command, it's the bed temperature setting at the very beginning of the G-code file generated by Slic3r. I'll try with your M190 S0 command.
Btw that bug is now fixed in my latest firmware, 0.65g-dc42 described in another thread.
Thanks for your commands. I tried them, the printer seemed to move faster but the overall time remained quite the same. I understand that moving faster can generate quality issues, that's not a problem for the moment, I want to check for the limits. Later on I'll certainly use at least two configurations : one for rapid prototyping where quality is not mandatory but speed is, a second one for the definitive printings.Quote
dmould
You are possibly running up against the quite low default max speed. Use the M203 command to change
Re: Print speed, hot end air flow direction, unstopped bed heating June 17, 2014 08:58AM |
Registered: 9 years ago Posts: 2,472 |
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paflviet
Thanks for your commands. I tried them, the printer seemed to move faster but the overall time remained quite the same. I understand that moving faster can generate quality issues, that's not a problem for the moment, I want to check for the limits. Later on I'll certainly use at least two configurations : one for rapid prototyping where quality is not mandatory but speed is, a second one for the definitive printings.Quote
dmould
You are possibly running up against the quite low default max speed. Use the M203 command to change
As I spent some time testing dc42 latest firmwares I didn't performed all the tests I intented to do with your configuration but I'll study it more thoroughly later.
Once again, thanks to all.
Patrice
Re: Print speed, hot end air flow direction, unstopped bed heating June 20, 2014 03:06PM |
Registered: 8 years ago Posts: 21 |
Re: Print speed, hot end air flow direction, unstopped bed heating July 03, 2014 05:33AM |
Registered: 8 years ago Posts: 138 |
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dmould
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paflviet
My real concern is about changing the printing speed : as long as I understand the print time is directly related to the speed for print moves, and the speed influences the print quality as a side effect.
Slic3r has a print tab with a speed sub-tab, I've tried to modify the settings one after another to check carefully (and learn) which parameter had which effect, nothing changed. I also read quite all the topics from this forum, every topic about speed directed me to this Print/Speed tab.
I did a diff on different versions of the generated G-code file (same STL source file, only one parameter changed at a time, ...), they seem to incorporate various speed settings but the print time remains constant no matter the change I test.
You are possibly running up against the quite low default max speed. Use the M203 command to change (see below).
I print with 65mm/s for print moves and 100mm/s non-printing moves (which could probably be increased if I also increase the max s[peed setting). At higher print speeds you will run up against the maximum extrusion limit - the extruder cannot push plastic through the nozzle fast enough and so the extruder motor starts skipping. You should however also increase the stepper currents in your config file otherwise you will get steppers skipping prematurely. Increasing to 1000mA is safe enough.
My config.g file (on the SD card) has the following:
M203 X6000 Y6000 Z500 E6000 ;set max feedrates - divide by 60 for mm/s
M201 X1500 Y1500 Z30 E500 ;set accels
M906 X1000 Y1000 Z1000 E1250 ;set currents
The time estimation calculated by the slicing program will be calculating based on the set speeds rather than the speed the machine actually prints at if it is limited by the max speed, and in addition may well not take into account either acceleration or extruder retraction delays, and so will tend to be overly optimistic. For short moves (such as infilling narrow areas) the print speed is constrained by the acceleration to be a *lot* slower than the speed set.
Dave
(#106)
Re: Print speed, hot end air flow direction, unstopped bed heating July 03, 2014 05:49AM |
Registered: 9 years ago Posts: 14,639 |
Re: Print speed, hot end air flow direction, unstopped bed heating July 03, 2014 08:19AM |
Registered: 8 years ago Posts: 138 |