Kisslicer 1.4.4.8 Cubex & seam

[giovanni...@gmail.com]

I've made just a few tests with a 0.2mm layer thickness and the new 1.4.4.8 but I've not been able to find the right M227/228 settings, the seam has always a lack of material at the beginning of the loop.

With the older Kisslicer the seam was better.

Did someone improve the seam quality with the 1.4.4.8 on the Cubex ?

[Scott]

I've been having the same problem for a while now. It only seems to happen when going from short segments (less than a few mm) of sparse infill to a loop. If it completes a long infill segment then goes to a loop, the loop will have enough material. When I started using 1.4.4.8 I had trouble getting enough material when sparse infilling, so I did a lot of test prints and got that fixed, but now the low material at the beginning of loops is the problem. Maybe it has something to do with M228 S&P? I cant seem to narrow down what those settings are doing, and when I change them it always seems to make it worse. Giovanni, have any luck with this problem?  I read on here a few weeks ago someone else had the same problem. 

Today, this problem lead to filament flow failures....It needs solved! 

[giovanni...@gmail.com]

M227/228 is not related to Flow Failure.

Flow failure are caused by filament diameter too big or too small.

To avoid Flow Failures use only filaments 1.75mm +/- 0.05 ( measure with a good caliper the diameter of the filament when you have a "Flow failure" because the filament doesn't have the same diameter along the coil ).

Feed directly the extruders, don't use the feeding tubes.

Increase the voltage of your extruder like described here ( but be careful, check you motor, it doesn't heat )  : 

https://groups.google.com/forum/?hl=it#!topic/kisslicer-refugee-camp/cenVYBGtew0

I've used a PVA filament that was mainly 1.75-1.8mm, but every 10-15 meters of filament the diameter rose to 1.82-1.84 producing the "Flow Failure".  Now by feeding directly the extruder and having increased the voltage to 1.5V this filament works good.

[PenskeGuy]

On Tuesday, July 29, 2014 12:21:00 PM UTC-7, Scott wrote:

I've been having the same problem for a while now. It only seems to happen when going from short segments (less than a few mm) of sparse infill to a loop. If it completes a long infill segment then goes to a loop, the loop will have enough material. When I started using 1.4.4.8 I had trouble getting enough material when sparse infilling, so I did a lot of test prints and got that fixed, but now the low material at the beginning of loops is the problem.

This seems due to hysteresis build-up in the material feed transport system. Think of it as a form of inertia. With a long run prior to a jump, extra stock will be present at the next path start, as the pressure inside the nozzle is high from a prolonged feed. With a short previous segment, the pressure hasn't enough time to build up, so the suck function pulls more than it did at the end of the long path. Combine that function with the "gap" Loops in v1.4.4.8 and you have a nozzle starve at Loop path start following a short path. Previous versions would close the Loop by coming back to the start point, instead of just short of it, but too much material was being deposited there all the time.

Unsure of how this should be addressed. Perhaps adjust the Prime/Suck values to see if that helps. If it does, a dynamic Prime/Suck proportional to path length might be a solution. IOW, higher Prime/Suck at the end of a long path prior to a Jump—lower Prime/Suck at the end of a short path.

I really like the parts I've been getting with the Gap Loops, so don't want that messed with if it screws the overall quality.

[giovanni...@gmail.com]

Le mardi 29 juillet 2014 21:21:00 UTC+2, Scott a écrit :

I've been having the same problem for a while now. It only seems to happen when going from short segments (less than a few mm) of sparse infill to a loop. If it completes a long infill segment then goes to a loop, the loop will have enough material. When I started using 1.4.4.8 I had trouble getting enough material when sparse infilling, so I did a lot of test prints and got that fixed, but now the low material at the beginning of loops is the problem. Maybe it has something to do with M228 S&P? I cant seem to narrow down what those settings are doing, and when I change them it always seems to make it worse. Giovanni, have any luck with this problem?  I read on here a few weeks ago someone else had the same problem. 

I usually print the parts with at least 2 loops and loops go from inside to outside, by that way the distance prior the beginning of the external loop will always be the same ( = from end of internal loop to beginning of external loop) and once you've found the right M227/M228 the seam will always look the same independently from what was printed before.