UM2 sequence before print...

[chrisr 18]

Couple of quick questions:

Before a print, both the extruder and bed are first heated up to temperature.

1) Am I right in thinking this function is carried out by the UM2? i.e it's not from instructions in the prints gcode ?

Next, the bed is raised to ~2cm below the extruder and the extruder is primed (in the top left corner) for a short while.

2) Is that a function also carried out by the UM2, rather than instructions in the gcode?

Finally, the bed gets raised to the correct height for printing and the print begins.

3) Is that final bed raising to print height also carried out by the UM2 or is that when the prints gcode starts executing?

Reason I'm asking is I'm trying to figure out what prefix and postfix gcode I may need for KISSlicer.

Thanks in advance for any help :smile:

 

[IRobertI 516]

Yes, yes and yes. I know someone posted a suitable pre- and postfix for KS here on the forums a while back but I can't find it at the moment. I'll look around some more.

Alternatively I think you can switch over to RepRap flavour in cura and get some code that way.

 

[IRobertI 516]

Found this:

http://umforum.ultimaker.com/index.php?/topic/6885-kisslicer-1407/

Have not tried it myself yet (I've been saying for months I need to get KS up and running... I even paid for a license *sigh*)

 

[chrisr 18]

Brilliant thanks! That looks a very useful thread indeed :smile: I did do a forum search but found nothing.

I paid for a KISSlicer license as well and thought similar that I really ought get my head around all those scary looking settings...

I now get why Daid had the UM2 control the initial warm up (rather than from Cura) as it's a much more flexible way of starting especially with other slicers in mind.

Was your answer 'yes' to 3) that it's the gcode starting which causes the bed to finally raise to print height?

I'm going to be getting my head around gcodes from today onwards... I came across this: http://www.cnccookbook.com/CCGWizardE.html

- which I thought looked interesting from the point of view of a complete gcode newb like myself!

Oh! and this: http://openscam.org/

 

[IRobertI 516]

Oops, sorry about the last "yes" hehe. If you look at the Gcode of a file you'll see that the first layer starts with something like:

G0 F12000 X31.203 Y46.524 Z0.200

so it's the actual Gcode telling the printer to go towards the center of the platform and raise the bed at the same time.

 

[chrisr 18]

Thanks :-)

 

[chrisr 18]

Oops, sorry about the last "yes" hehe. If you look at the Gcode of a file you'll see that the first layer starts with something like:

G0 F12000 X31.203 Y46.524 Z0.200

so it's the actual Gcode telling the printer to go towards the center of the platform and raise the bed at the same time.

 

Ahhh.... is the UM2s X-Y origin (0,0) the top left hand front part of the build plate? i.e the position where the nozzle primes itself before printing? Kisslicer has the bed middle as 0,0

 

[tinkergnome 926]

Ahhh.... is the UM2s X-Y origin (0,0) the top left hand front part of the build plate?...

 

Short answer: yes

 

[chrisr 18]

Thanks TinkerGnome, I'm guessing the origin will need to be offset by half the printer bed dimensions... now wondering if this should be -115 and -112.5. Hmmm.....

 

 

 

[IRobertI 516]

Yup, that would be correct. You might need to tweak it slightly later if you're trying to use 100% of your printing volume. There can be slight differences in end stops and fan shrouds that alter the build space a bit.

 

[chrisr 18]

Thanks Robert, just to clarify, should the values for the origin be negative ? i.e - 115 and -112.5. I'm wondering that the center being 0,0 (for Kisslicer) then it kinda makes sense that the (UM2s) left hand front corner would be in a negative direction for both the x and y co-ords. Am I right in thinking that?

I'd try running it, but I'm just a bit worried about banging my UM2's nozzle into the end stops.... :eek:

 

[IRobertI 516]

The values should not be negative, both should be positive.

And don't worry too much about running into the walls. It sounds horrible but shouldn't damage your printer.

 

[eldrick 64]

Set the KS bed center on the machine tab to X=115, Y=112.

 

[chrisr 18]

Thanks all. :-)

The settings for the bed are spot on. Now I've just got to work out why the bed wants to home twice before priming the nozzle and I'm then getting nothing extruded when the print starts... it appears that the feeder is retracting but not feeding the same amount despite those two distance settings being identical in KISSlicer. Very bizarre :???:

 

[IRobertI 516]

The bed up and down thing I don't know about, it was mentioned in the other thread.

As for the other thing, check that Printer -> Firmware -> Firmware Type is set to Absolute E.

 

[chrisr 18]

Ah. Good call. Thanks Robert. It was set to Relative E. I'll try it all again tomorrow.

 

[axsdenied 0]

If you get it working properly, can you post all the settings here.

I tried playing with slic3r but got scared and stopped experimenting after nozzle bumped the clip.

[chrisr 18]

Yes certainly. That's why I'm approaching this cautiously. It didn't help that my UM2 gave me a caution, warning me that I was overriding the printer settings... before I pressed 'continue' <gulp>

My main reason for looking at KISSlicer was for the support generation it produced which gave better results "out of the box" than Cura for a particular print I've been trying. Here:

http://www.thingiverse.com/thing:637261

Since then I've "discovered" you can generate supports outside of Cura and then import the whole thing back in as an .stl using this amazing free software: mishmexer, http://www.meshmixer.com/

I do want to persevere with KISSlicer as I've bought the damn thing and it seems to me that it's worthwhile perservering with. I've just got to get my head around it with the patient forum help here and also learn some Gcode in the process, which altogether isn't a bad thing!

So yes, if I get it all sussed (I hope) I'll gladly post up all the settings that work for the UM2 :smile:

 

[chrisr 18]

If you get it working properly, can you post all the settings here.

I tried playing with slic3r but got scared and stopped experimenting after nozzle bumped the clip.

 

Got my UM2 working with KISSlicer. Here are the settings I'm using.

http://umforum.ultimaker.com/index.php?/gallery/album/1757-kisslicer-settings/

 

[axsdenied 0]

Thank you!!!

Greatly appreciated!!!