Cura settings for Mendel90

Re: Cura settings for Mendel90

dawa — Tue, 09 Dec 2014 15:50:50 -0500

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

Re: Cura settings for Mendel90

minimales — Mon, 08 Dec 2014 09:53:41 -0500

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

Re: Cura settings for Mendel90

dawa — Mon, 08 Dec 2014 03:02:57 -0500

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?

Re: Cura settings for Mendel90

minimales — Mon, 08 Dec 2014 02:09:51 -0500

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

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 17:44:11 -0500

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?

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 15:57:32 -0500

Thanks a lot, minimales, I'll try!

Re: Cura settings for Mendel90

minimales — Sun, 07 Dec 2014 15:55:46 -0500

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

Re: Cura settings for Mendel90

Arakon — Sun, 07 Dec 2014 15:45:09 -0500

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).

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 15:44:13 -0500

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

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 15:08:41 -0500

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?

Re: Cura settings for Mendel90

minimales — Sun, 07 Dec 2014 14:52:57 -0500

I will give them a try when the current print finishes. Did you set to layer time to something higher, this is really small. In the meantime you could give this retraction test a shot, it should usually print very well as its not that small and narrow.

And as always: Try lower temperatures on the hotend. :)

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 14:39:25 -0500

Looks nice!

I had retract on, and I looked at the layer visualization, and I could see the retract lines.
I also saw the extruder going backwards during the print, which should correspond to retracts.
Probably the wrong values somewhere.
I found batteries for my old digital camera... so here are two pictures of the thing. I attach gcode too.
The two pictures are the result of slicing with Cura.
I also attach the scad and the two gcode files.
If you happen to have the energy ... :-)

BR,
David

Re: Cura settings for Mendel90

minimales — Sun, 07 Dec 2014 14:05:58 -0500

David,

maybe you forgot to switch on retract? I have activated retract on the basic page and and the speed on the advanced tab is set to 35mm/s and retract distance 0.5mm. The result is fine but yes, the dimensions are not the way they should be but for this project I go with the power drill to get the dimensions right.

[attachment 44806 20141207-IMG_1359.jpg]

Ingo

Re: Cura settings for Mendel90

nophead — Sun, 07 Dec 2014 11:28:50 -0500

Actually Github provides a Wiki with each project so maybe user contributions could go there: [github.com]. I am not sure if anybody with a github account can edit it or just named contributors. Perhaps somebody can try editing it.

The retract options for SF are on the Dimension tab.

Cura already has a separate engine / GUI structure. The engine is a separate GitHub project.

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 09:39:23 -0500

Thanks, I understand.
I just tried some prints of the same model with Cura and SF, and SF gives much better result, no stringing.
This may be because of my lacking configuration skills.
But I can actually see that even the Cura sliced object does retracts during the print.
There should really be a fast slicer for repraps, not written in python.
If I get time, knowlegde and energy, I will write one in Haskell :-)

I think the user interface, the printer specific config, and the slicer engine should be separated.
There should be an engine that should be shared between various projects. After all, its just a compiler.

BR,
David

Re: Cura settings for Mendel90

nophead — Sun, 07 Dec 2014 09:18:37 -0500

I think Cura sometimes misses out the retracts because it is aimed at Bowden machines that don't retract well. For that reason and the fact it doesn't get dimensions accurate I don't use it.

Also Cura and Slic3r are continually changing so I can't support them as I simply don't have time to test each new version. Skienforge never changes so there is no on going work involved to support it.

Re: Cura settings for Mendel90

dawa — Sun, 07 Dec 2014 06:21:14 -0500

Hello,
I just tried Cura 14.09 with the settings provided in this thread, by ecooak and Neil Darlow.
Thanks! I works!

I would be good if nophead could put the "latest cura settings" on his blog or somwhere easy to find, where it could be maintained.
I think many mendel90 users would benefit and could also contribute.
(Even if cura is inaccurate for layer height 0.3, it is *way* faster than skeinforge, which takes almost as long as the print itself, sometimes, and has a hopeless user interface, where you cant avoid saving the configuration without even knowing it... I save all the SF config tree in a tar ball to protect it from itself ;-) Maybe one should even have a git repo for it? sorry for this off-topic parenthesis)

I tried a small print, and there is some "stringing". Some very thin strings from where the retracts have been made.
Could it be wrong temp or wrong retract settings? Unfortunately I dont have a camera that can catch these thin strings.
I have just changed from the green filament included with the kit, to esun black PLA, 2.92 mm. I think I followed all the steps, to adjust E_STEPS_PER_MM, both in firmware and Cura. It worked well in skeinforge, no strings there. I think both SF and Cura have retract speed 40 mm/s, but Cura now has retract distance 4.5 mm and SF I think has 1 mm. But I have difficulties navigating in the SF settings, so I dont really know.
The temp is still 185 degrees. Maybe this should be changed?
But the stringing may be an indication that the temp is too high?
Any advice?

BR,
David

Re: Cura settings for Mendel90

minimales — Sun, 30 Nov 2014 16:47:57 -0500

I am printing 3D printed mechanical Clock with Anchor Escapement as a present for my dad. Most of the parts are done, two need modifications but the spring was the hardest part which introduced to much shaking.

Ingo

Re: Cura settings for Mendel90

nophead — Sun, 30 Nov 2014 14:54:09 -0500

Please post the gcode and I will try it here. I have never had my machine do that.

Re: Cura settings for Mendel90

minimales — Sun, 30 Nov 2014 14:24:45 -0500

I can play a low note on both belts and dont get any ghosting/echo effects around holes or prints.

My laptop cannot provide enough USB Speed, I print everything from SD Card and only use the laptop for selecting files via Pronterface.

I did not touch any paramter from the provided PLA 0.2 profile as well the Melzi firmware. Feed Rate is at 50mm/s and Acceleration at 2000 but I can run a diff on the files maybe I did touch something by accident.

The perimeters print okay but the violent shake seems a littlebit to much for the mechanic to follow so the head swings over the perimeters.

Re: Cura settings for Mendel90

nophead — Sun, 30 Nov 2014 09:39:52 -0500

Also I think there is something wrong with your printer or settings if it can't print anything Skeinforge throws at it. Perhaps the belts are loose or the speed or acceleration set too high, or not enough USB bandwidth. I print everything at 50mm/s with acceleration set to 2000 and don't get problems like that. It simply slows down on fine zigzags due to the acceleration limit.

Re: Cura settings for Mendel90

neildarlow — Sun, 30 Nov 2014 07:37:31 -0500

Hi,

You can produce good infill with Skeinforge although it takes a little practice to assess the required density and orientation. I have printed the Wade's gear set using Skeinforge to slice it.

For your spring objects, try and make them a multiple of the printed line width (I use 0.5mm) and avoid gaps which might cause Skeinforge to produce zig-zag infill. Although, if your bed adhesion is good, that really is not a problem.

Regards,
Neil Darlow

Re: Cura settings for Mendel90

minimales — Sun, 30 Nov 2014 07:18:13 -0500

Thanks Neil, its working right away with excellent results. The dimensional accuracy of cura seems to be a weak point but the infill on small parts like gears is something I wish for skeinforge. Just produce lines that follow the perimeter when a normal infill pattern shakes the printhead to dead and will destory the object while printing.

Ingo

20141130-IMG_1269.jpg

Re: Cura settings for Mendel90

neildarlow — Sat, 29 Nov 2014 10:50:36 -0500

Hi,

Here are my version of nophead's standard start and end GCode adapted for Cura 14.09. Bed fan control is included in end.gcode but needs to be uncommented to enable.

start.gcode:

;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
G21 ; metric values
G90 ; absolute positioning
M83 ; set extruder to relative mode
G92 E0 ; zero the extruded length
M107 ; start with the fan off
G28 ; home all axes
G1 X0 Y98 F6000 ; go to the middle of the front
G1 Z0.05 ; close to the bed
M104 S{print_temperature} ; set extruder temp
M190 S{print_bed_temperature} ; set bed temp & wait
M109 S{print_temperature} ; wait for extruder temp
G1 X50 E5 F200 ; make a thick line to prime extruder
G1 E-1 F1200 ; retract a little
G1 Z0.3 ; lift Z
M82 ; set extruder to absolute mode
G92 E0 ; zero the extruded length again

end.gcode:

;End GCode
M104 S0 ; turn off extruder
M140 S0 ; bed off
M107 ; carriage fan off
M83 ; set extruder to relative mode
G92 E0 ; zero the extruded length
G1 E-1 F1200 ; extra retract
;G1 X-100 Y100 F6000 ; go to back
;M42 P28 S255 ; bed fan on
G1 Z200 X-100 F6000 ; go to top
;G4 P300000
;M42 P28 S0 ; bed fan off
G1 Y-100 ; bed to front
M84 ; disable motors
;{profile_string}

Regards,
Neil Darlow

Re: Cura settings for Mendel90

minimales — Sat, 29 Nov 2014 08:35:15 -0500

Hello everyone,

Could someone provide an config file for the current version of cura? I figured out some things that need a change but I dont know how to include the ooze free restart to current version as there still seems no switch to configure cura to provice code with relative e.

I found a config at [wiki.imal.org] but these settings look outdated as cura 14.09 behave wrong, the retraction is working way to fast while the rest seems okay at least to me. The first layer is printed to high but maybe I can correct that as I take a closer look at the g-code.

Thanks,
Ingo

Re: Cura settings for Mendel90

nophead — Sun, 04 Aug 2013 17:39:20 -0400

Yes it prints fine with M82 but you of course lose the advantages of relative E. I.e. ability to pause mid print and change the filament, or splice together bits of g-code.

Re: Cura settings for Mendel90

richgain — Sat, 03 Aug 2013 10:06:00 -0400

Thanks, that's interesting Chris. I've not tried M82 before and wasn't aware of what it could do. I will have to investigate further.

Richard

Re: Cura settings for Mendel90

nophead — Sat, 03 Aug 2013 09:04:20 -0400

M82 works. I am printing gcode generated from it now, but it seems very buggy.

Re: Cura settings for Mendel90

nophead — Sat, 03 Aug 2013 05:44:23 -0400

Can't you simply add M82 to start.gcode?

Re: Cura settings for Mendel90

Alzibiff — Sat, 03 Aug 2013 05:26:53 -0400

FWIW, I am using V13.03 of CURA with my stock + Panelolou2 Dibond Mendel90 and it works just fine with the changes referred to for relative extrusion. It is a real pity that this has not been taken forward with later versions of CURA as the package is very well thought out and much easier to manage than SF which is still the one I use 99% of the time.

Alan