Cura settings for Mendel90

Thanks!
Nice example file! I'll try.
It also tests bridging.
Actually I need to enhance that too.
I tried a bridge of 100 mm, and it worked. But the first layer printed in thin air starts to hang down a bit when the second layer is printed on top of it.
Could it be that it expands by the heat fron the second layer?

I tried the Retract file you sent with Cura.
There is no stringing in the sense I showed from my very small print.
but on Retract2.jpg one can see on the shadow to the right that one bridging string got lost, I think when the second layer came on.
and in Retract2,jog one can see in the holes that there are small unveven nags along the edges.
Otherwise I am surprised it went quite well!

Since I have 185 degrees and I changed from green PLA to black, I expected to need a higher temp.
But I dont know how to detect the need of higher or lower temp, really.
How to tell over extrusion from too high temp?
I think it can be one of these two.

BR,
David

Edited 1 time(s). Last edit at 12/07/2014 03:44PM by dawa.

I have massive stringing issues with cura too. If I slice the same file with simplify3d, I get no stringing at all, but instead it messes up quite a few other things (mis-slicing surfaces, even placed 2 very thin surfaces into an open tube).

Hi Dave,

Check the retract settings, you retract waaaayy to far, must be 4,5mm like the default. Go to advaned and set it 0.5mm and 30...40mm/s like I said, the retract in this file is way to fast!

Ingo

Thanks a lot, minimales, I'll try!

I set the retract to 0.5 mm 40 mm/s as you suggested minimales, but the result is the same. Kind of "hairy".
Could it be over extrusion?
Doest it really matter what you enter as "E_STEPS_PER_MM"? in Cura? it is already in the firmware, what does cura do with it?

Yes it does matter but you simply set it to zero and the firmware value is used instead. I can post my ini after work as soon as I get home.

Its very hard to come by when it comes to stringing on such tiny objects. You really have to keep your extruder temperature low and on the other hand keep in mind how little the extruder has to transport. With the retract the gear grinds into the filament all the time and the almost same spot.

I got white filament from the same brand that never leads to ooze out and black filament where always a stroke from the ooze free start to the starting point appears. I had to lower the temperature for the black one even more but on large prints the edges tend to curl up.

One some filaments it might work but for most of the stuff there is no "one setting fits it all".

Ingo

Hello,
Thanks! Yes it would be great to try your settings to compare with mine.
The same filament doesnt string with skeinforge on the same print, so it is not the filemant's fault, when it somes to stringing.
I am starting to suspect my bed has lost the level adjustment, I have to recalibrate it to be sure.
I'll try calibrating by printing one layer near the plate's corners.

It is hard to guess what is the right temperature and extrusion. I might have measured the filament diamater wrongly.
My digital calipers have an error of 0.03 mm. How accurate does it have to be?

Hi Dawa,

Follow nopheads procedure, noone knows the Mendel90 better!

The caliper doesn't help you here. I've printed the holder for the dial gauge and moved the head with the pronter-interface around the bed for exact leveling at around +/- 0.05 as far as I remember. It depends on your first layer height. When its visible that the infill on one corner gets thin as the head is t0o close to the bed and on the other side the nozzle is not squashing the deposited filament its quit clear that the leveling is inaccurate for good results. Keep in mind the headbed might bend when you head it up. Maybe you head it up and check the leveling again

After remounting the printhead I used a piece of paper to check for the correct distance between printhead and surface. I got three layers of thin tape between the endstop and the x carriage for fine adjustment in case I need to adjust the height. I guess this happends every 8-12 weeks while printing 12h a day. Just dont move the printer around or tip it to one side.

I got two washers in the back and the rest was done by adjusting a spindle till the tilt of the x-axis matches the printbed.

Ingo

Edited 2 time(s). Last edit at 12/08/2014 09:57AM by minimales.

Hello,
I printed one layer near the edges of the plate, and it was fairly ok. within about 0.05 mm.
Then I tried to raise the temp to 200 degrees, and now it works much better!
But I still see that the ouline bends up a bit in its end, when the printhead moves away quickly in order to start the "real" print.
Is there a missing retract there?
I tried 205 degrees, but it started to get hairy in a corner of a small cube. Hmm. It si so difficult to know what parameter to change.

I try to make it work well with SF before I try with Cura.
Bridging works fine now with both Cura and SF for small distances like 2 cm, but i want 10 cm, which is harder.
Any advice about long bridges? (it is because the "raptor hand" requires it, for the e-nable project)
I have almost succeeded, tying to change feedrate and flowrate in SF, now trying 35 mm/s.
Still there are strings hanging a bit under the bridge. (I should post this in some slicer settings thread instead, sorry)

I want to try these settings: RyanMarks Skeinforge PLA Profiles

BR,
David