Print Settings Help/Info

[verdonko 0]

Hello All...my first post!

As a new Ultimaker user and a high school engineering teacher we are excited to get our ultimaker making quality prototypes as soon as possible.

TWO questions/requests for help:

1) We want to experiment to get best prints. Which settings should we start with? Which settings should we keep track of? (thinking of creating a photo-log...list of settings + photo of print) Has anyone already done this?

2) Ultimaker Controller...what are all the menu options? and what do they all mean? (i.e. Vxy-jerk ?!?) Is there a PDF out there for guiding us through the Ulti-Controller menus?

Thanks in advanced for the great community and support! -Olaf

 

[gr5 2,071]

#1

Keep track of every setting. Whenever you save a gcode file the settings that you used get saved along with it at the end. You can later choose "file" "load profile from gcode" to see what settings you used at the time. Write down the most important settings: speed, temperature, layer height.

I recommend you stick with .2mm layers for 99% of what you print. But vary speed and temperature often depending on your needs.

Everytime you start a print have a notebook where the student must write down the date/time which gcode file was printed, color of filament, and a few details like the 3 parameters I mentioned above.

#2

I don't know if there is something that explains them. And they change when you start printing (tune menu).

Don't mess with jerk. lol. It's fine as it is.

In physics velocity is the change in position (derivative). Accel is change in velocity. Jerk is change in acceleration. But Everything is discreet in the software (not continuous) so jerk is always infinite at the vertex of every move (theoretically).

So instead they created something called "jerk" but it's not jerk. It's a max delta velocity vector at the vertex.

So if X velocity is 100mm/sec and y velocity is 0 and you hit a 90 degree corner at that speed, jerk would be considered to be sqrt(100^2+100^2) or 70.7mm/sec. Since max jerk is set to something like 10 or 20 mm/sec the X axis is instead slowed down to the speed =(max jerk*1.404). This is for 90 degree corners. for only slight angle change the UM doesn't slow down as much because the velocity change at the vertex is smaller.

 

[kolia 31]

You just gave me an idea of professional reconversion =) Which country are you from? Somewhere in Scandinavia?

 

As a new Ultimaker user and a high school engineering teacher

 

 

[lumeria 0]

#1

Keep track of every setting. Whenever you save a gcode file the settings that you used get saved along with it at the end. You can later choose "file" "load profile from gcode" to see what settings you used at the time. Write down the most important settings: speed, temperature, layer height.

I recommend you stick with .2mm layers for 99% of what you print. But vary speed and temperature often depending on your needs.

Everytime you start a print have a notebook where the student must write down the date/time which gcode file was printed, color of filament, and a few details like the 3 parameters I mentioned above.

#2

I don't know if there is something that explains them. And they change when you start printing (tune menu).

Don't mess with jerk. lol. It's fine as it is.

In physics velocity is the change in position (derivative). Accel is change in velocity. Jerk is change in acceleration. But Everything is discreet in the software (not continuous) so jerk is always infinite at the vertex of every move (theoretically).

So instead they created something called "jerk" but it's not jerk. It's a max delta velocity vector at the vertex.

So if X velocity is 100mm/sec and y velocity is 0 and you hit a 90 degree corner at that speed, jerk would be considered to be sqrt(100^2+100^2) or 70.7mm/sec. Since max jerk is set to something like 10 or 20 mm/sec the X axis is instead slowed down to the speed =(max jerk*1.404). This is for 90 degree corners. for only slight angle change the UM doesn't slow down as much because the velocity change at the vertex is smaller.

 

Your very clear example makes me wonder... If an axis slows down like you calculated, will this effect the filamentfeader? When the axis slows down to 70 and filament is still pushed for 100, wouldn't that give a bit more filament at those slowdown positions?? Or will the filamentfeader/extruder automatically adjust??

 

[gr5 2,071]

Great question. The extruder will automatically adjust.

All moves are performed by the Marlin firmware which is pretty good stuff. It is pretty smart. All of the moves in gcode are X,Y,Z,E (E for extruder) moves - they are 4 dimensional or 4 axis moves (actually typically Z doesn't move for a large percent of the moves). These moves are required to be linear moves. This means you can't move the X at the same velocity as Y because the distance to cover may be different. So to move in a "straight line" you have to make sure the X,Y,E velocities are all at the same ratio as the total distance to cover.

This means as the X or Y movement decelerates, the E (extruder) also decelerates.

Unfortunately, because of the long bowden tube, and because of the somewhat high pressure of plastic in the nozzle, there is a lag (time delay) in extrusion. So what happens is you get a tiny amount of overextrusion as it slows down and underextrusion as it speeds back up. This is mitigated with slower print speeds.

It's rarely a problem though. But when I look at a print of a cube I can tell if the print head moved clockwise or counter clockwise because of this "delay" or "lag".

 

[verdonko 0]

Thanks!

That will be helpful...I already have a black book for our laser engraver (same idea to record settings. However no where near as many as Ultimaker / Cura!)

Two follow questions:

1) I noticed on the <Start/End-GCode> tab that there are several lines for setting information...do i type that in, or does CURA generate that? And I noticed also that Gcode line M107 (start with fan off)...can I just remove this line? I have been starting prints, then having to go into Ulti-controller to start/set fan speed...I really would like the fan to come on automatically at a default or set speed. (yes I have the "enable cooling fan" checked)

2) is there anyway to control the motors via the Ulti-controller? I want to be able to move the print head out of way and lower print bed.

THANKS for the help and support! happily printing away in Vermont! -OV-

 

#1

Keep track of every setting. Whenever you save a gcode file the settings that you used get saved along with it at the end. You can later choose "file" "load profile from gcode" to see what settings you used at the time. Write down the most important settings: speed, temperature, layer height.

I recommend you stick with .2mm layers for 99% of what you print. But vary speed and temperature often depending on your needs.

Everytime you start a print have a notebook where the student must write down the date/time which gcode file was printed, color of filament, and a few details like the 3 parameters I mentioned above.

#2

I don't know if there is something that explains them. And they change when you start printing (tune menu).

Don't mess with jerk. lol. It's fine as it is.

In physics velocity is the change in position (derivative). Accel is change in velocity. Jerk is change in acceleration. But Everything is discreet in the software (not continuous) so jerk is always infinite at the vertex of every move (theoretically).

So instead they created something called "jerk" but it's not jerk. It's a max delta velocity vector at the vertex.

So if X velocity is 100mm/sec and y velocity is 0 and you hit a 90 degree corner at that speed, jerk would be considered to be sqrt(100^2+100^2) or 70.7mm/sec. Since max jerk is set to something like 10 or 20 mm/sec the X axis is instead slowed down to the speed =(max jerk*1.404). This is for 90 degree corners. for only slight angle change the UM doesn't slow down as much because the velocity change at the vertex is smaller.

 

[verdonko 0]

You just gave me an idea of professional reconversion =) Which country are you from? Somewhere in Scandinavia?

 

I am in Vermont, USA.

(Dutch name though...both parents from Nederland)

What did you mean by "You just gave me an idea of professional reconversion" ?

-OV-

 

[gr5 2,071]

1) I noticed on the <Start/End-GCode> tab that there are several lines for setting information...do i type that in, or does CURA generate that?

 

Whatever is typed into the settings here ends up in the gcode at the start (or end).

Instead of deleting the fan off line you could also optionally turn it on:

M106 S128 ;turn fan on half speed

M106 S255 ;turn fan on full speed

More gcodes explained here:

http://reprap.org/wiki/G-code#M106:_Fan_On

 

2) is there anyway to control the motors via the Ulti-controller? I want to be able to move the print head out of way and lower print bed.

 

Yes. You can do this from Cura print menu, or UC, or gcodes or by pushing with fingers. I prefer to use fingers. I push the head out of the way and rotate the Z screw at the bottom. You need to disable steppers sometimes which I can also do in UC.

In UC go to "prepare" "move axis". But never use this for moving extruder as it can cause problems! Instead move by hand. To disable steppers it is also under "prepare" menu.

 

[kolia 31]

What did you mean by "You just gave me an idea of professional reconversion" ?

-OV-

 

I meant that you have an interesting job title I'm an engineer, but I didn't have an engineering teacher in highschool for sure!

Now after a few years, I can see how our education system would make even better engineers by having such courses earlier. And more important, it would encourage people to stay closer to technical fields. Lots of engineers in France are very quickly far from any technical issue... that's a bit sad imho.

-Sorry for the digression and have a good day in Vermont!-

 

[LePaul 314]

I am in Vermont, USA.

(Dutch name though...both parents from Nederland)

What did you mean by "You just gave me an idea of professional reconversion" ?

-OV-

 

Ah a fellow New Englander

 

[Nicolinux 288]

@verdonko: Here are the Cura settings/options explained:

http://blog.ultimaker.com/cura-user-manual-first-time/

http://blog.ultimaker.com/cura-user-manual-full-settings/