Here is the file, you’re really kind! Thanks a lot. Cura is the slicer.
Hey @MattG ,
Thanks for your reply. I had this kind of imperfection in two different points of the printer, not on the same level: that’s the reason for which I’m really curious to understand the cause of the problem. Here is the Gcode if you want to take a look. In any case, I’ll check tomorrow but apparently the hotend is moving without any problem and it’s the first time that I have this kind of imperfection.
Fans were running at 100%. I cooled down the temperature manually after the first hour because I noticed that it might be a bit to high.
@federicogiacone
Frankly I sincerely doubt this is a cooling issue. I just doesn’t make sense. Before you risk your health, see my reply below.
There is a whole lot of guessing going on in this thread with very little information to go on. I’d be skeptical of any of these answers so far, even “slow the print down”. That one is used as a cure-all, but it isn’t always the right solution.
2 Likes
20% infill. The filament looks like really fine, so I won’t say that’s the cause of the imperfection.
Thanks, I’ll take a look at this and post some screenshots.
glad to help!
1 Like
Take all the time that you need, I’m not in a rush. It is just curiosity and willingness to learn
Hi @federico3 ,
Please check these 4 things:
1. Consistency of the filament diameter
3. Are you certain that your PTFE is still in good condition (no brown parts when you open the hot-end assembly on the white PTFE part)?
4. How well is your machine performing at this point mechanically? Are all the belts tightened etc?
I’m suspicious of option 1. and 3. but let’s see what you can tell us
1 Like
Hey Remcokatz,
Now I’m at home and tomorrow I’m not in the office, in any case, I’ll ask someone else to check it.
Thanks for your help
MattG
June 30, 2016, 5:53pm
19
Had a quick look at the gcode nothing glaringling obvious, the reason I was suggesting something mechanical rather than cooling or setting related is just because of the localisation of the problem, it doesn’t appear to be at the beginning or end of a tool path either. When you say this happened at two points, at different heights, were they in roughly the same location in x-y?
The hottend is moving freely… there’s nothing snagging, restricting the bowden tube at a certain point / extreme is there?
Curious to see the cause of this one!
Alright looking forward to the feedback!
Regarding point 1; Even cheap filament can look great but what you don’t see if it has diameter tolerance issues. Therefore you would have to measure it at several points on the spool with a caliper. So you can never say that filament is fine just by looking at it (even new spools). If you need help how to properly measure I can give some more info.
If you havent gotten any problems with the same spool and different prints then we can just move forward to solve your issue.
P.s. your retraction speed seems a bit aggressive but i’m not sure what the standard is for the 2+
MattG
June 30, 2016, 6:19pm
21
Seems unlikely to be a filament issue doesn’t it? What’s the odds on the filament having an issue at exactly the same section of the print for what must be about 100 layers? If I’ve had an under extrusion issue because of inconsistent filament is usually just drops a layer.
Oh it’s just an extra check to make sure that there’s no issues at all with the filament but I agree that this is not going to solve the issues alone :). I work in the filament industry so I kinda have a standard list of like 30 points that I work through group-wise to pin down where the issues are.
I think it is a problem of temperature.
This is an error in your retraction or pausing when you change layers. That is why it is occuring at the same area on the print, because that is where the zaxis is moving up. This is also why the error is occuring elsewhere on the print, but NOT in the same layers.
One of two things.
1. Your layer height retraction number is screwy. You are retracting so far that the head moves up, the next layer starts, but it takes awhile for the plastic to get out of the extruder.
2. Or more likely, you have a mechanical issue. The extruder pauses, the z axis moves up to the next layer, and when the extruder unpauses, it is slipping, jamming, etc. As more and more plastic is pushed into the extruder, it finally builds up enough push to continue printing.
3. This could also be caused by a worn, difigured, burned PTFE extruder lining, that it needs much pressure to get going after a pause, zaxis move.
All the other temperature, speed, gust of wind, etc. posts are simply not realistic.
I will bet you a candy bar that if you watch the print as it is happening, it will be exactly where you printer is changing layer height.
Perry
2 Likes
MattG
July 1, 2016, 3:14pm
25
Agree with everything here, but when I looked at the gcode for the area of the problem, the layer height appears to change at a different position for each layer???
In looking at the gcode, I am going to stay with my original analysis.
Hi Perry_1,
Thanks for your answer. On Monday, I’ll check if there is any mechanical issue with the printer but I’d say that the printer is working smoothly. I’ll also try to run again the same gcode file, in order to understand if the problem is due to an external factor or to a problem in the code/printer/material.
Federico
@remcokatz I’ve measured the filament in three random spots, the results are quite regular: 2.90, 2.87, 2.92 mm
The two imperfection are on two different points in two completely different positions on the x-y-z axis.
