Ultimaker Mark2 - The Smart Dual-Extrusion Upgrade

[dfrez 21]

2 hours ago, only_36 said:

The second issue is probably linked to my magnet provider as I suffer some head disassembly at Xmax/ Ymin location. Magnets not strong enough or extruder orientation not correct ? I have temporary improved it thanks to a bungee cord pulling the bowden tube to the rear... Any advice is welcome !  

 

 

Most likely magnets not strong enough. I had the same problem, even with "N52" rated magnets I got from eBay. I ended up buying the same rating of magnet from a more reputable source and they are significantly stronger, even though they are supposed to be the same "rating". 

[only_36 0]

@dfrez yes I have read you got the same kind of troubles. I have ordered new magnet from the recommanded shop as the first set was included in the cheap Mark2 kit from China. Electronic stuff is ok but I was not enough cautious with magnets quality.

Edited January 15, 2020 by only_36

[Anzen 0]

hello

 

with version 4.4 of cura whatever extrude that I select it is always extrude 1 which prints

 

merci

[tinkergnome 927]

22 hours ago, Anzen said:

whatever extrude that I select it is always extrude 1 which prints

 

Can you elaborate a bit - what you're trying to achieve?

A (single material) print with the second extruder only will probably need a different start script.

[Anzen 0]

Bonjour

merci pour votre intervention
j'utilise la version 3.6 de cura, perfectly works pour la sélection des extrudeuses
je prends la configuration avec la version cura 4.4 l'impression utilise toujours l'extrusion 1

 

avez-vous le même problème avec cura 4.4 et l'imprimante foehnsturm Mark2

Edited January 27, 2020 by Anzen

[tinkergnome 927]

Well, I'm not that familiar with Cura, but what i noticed is:

Cura always adds a toolchange command with the initial extruder number right at the beginning of the file - even before the start script. This does not work. The T1 command is needed "after" the start script.

(I don't know if former Cura versions handled it different).

 

I usually edit the gcode file manually if the print really needs to start with the second extruder.

 

It may be a possible workaround to add an additional tool-change command  at the end of the start script, but i have not tried it yet.

 

...
G92 E0
T{adhesion_extruder_nr}
;end of startup sequence

 

[dfrez 21]

My first dual extrusion print came out pretty good! Thanks to everyone who made the Mark2 project possible. 

[dfrez 21]

I've searched the thread but couldn't find anything similar. But I've noticed when I'm doing ABS and HIPS prints with the bed at 100C, the printer struggles with keeping the bed up to temp, which leads to the print warping and then popping off. With a single nozzle print, I have no issues with adhesion and keeping the bed at 100C. 

 

I currently have the top of the printer covered with an old printer paper box and the front covered with a plastic lid as a means to keep heat in. 

 

The bed gets up to temp like normal when everything is heating up, but once the nozzles are turned on and the print starts, the bed starts to cool. Sounds like a power budget issue to me. I haven't had the printer shut off at all with my current settings of 175/150/40/40. So perhaps I need to increase the budget (1st number) a little more so that the printer isn't afraid to apply more power to the bed to keep it at temp? 

 

I also saw an older post here about someone powering the bed with a separate PSU, which could be an option or replacing the 220W PSU with a 280W PSU. Both are options I suppose, but was wanted to see if there was a way to just make due with the current hardware. 

[Torgeir 243]

Hi dfrez,

 

I'm using a Dell 24 VDC 12.3 Amp ~295 Watt for an UM2. Sure no problem at all.

 

Here's a picture of it together with another 24 VDC PS delivering 360W, kind of the ones used in the new series of printers.

 

 

 

Thanks

 

Torgeir

 

 

 

[dfrez 21]

16 hours ago, Torgeir said:

Hi dfrez,

 

I'm using a Dell 24 VDC 12.3 Amp ~295 Watt for an UM2. Sure no problem at all.

 

Here's a picture of it together with another 24 VDC PS delivering 360W, kind of the ones used in the new series of printers.

 

 

 

Thanks

 

Torgeir

 

 

 

Hi Torgeir, 

 

thank you for the info. Do you do abs prints with your mark2 as well? Also could you provide the PN on that Dell PSU? Might be cheaper to find than the MeanWell. I just can’t make out the number in the picture. 

[Torgeir 243]

Hi dfrez,

 

This is Dell DA-2 Series

P/N: N112H

Model: D2950P-01

 

Just search google using: dell D2950P-01

 

This unit has the right type of connector, no extra work... 🙂

 

Good luck

 

Torgeir

Edited February 15, 2020 by Torgeir
Edit.

[georgp 0]

Hey Guys, 

 

I installed Cura 4.4.1 and I'm running the mark 2 extension software 19.03 but when my Print finished it does not home the head and does not lower the building plate either. So there will always remain a little dot at the end of a print. 

 

Any thoughts how to fix that?

 

Thanks

Georg

[tinkergnome 927]

4 hours ago, georgp said:

when my Print finished it does not home the head and does not lower the building plate either

 

Hi Georg,

 

was the print started from the SD-card on the printer like common? The firmware should perform the finishing steps in this case...? 🤷‍♂️
Were the "cooling down" and "print finished" screens shown as usual?

 

 

[georgp 0]

Actually I was printing via USB connection. Could this be the issue? 

And also the Fans on the sides seem not to work - just the main Fans is running when printing

 

Any thoughts on that?

 

Thanks for your help!

[tinkergnome 927]

8 hours ago, georgp said:

Actually I was printing via USB connection. Could this be the issue?

 

In this case you can add these steps to the end-script in Cura or to the according gcode script in the printing host (if applicable).

My "print finished" script in Octoprint looks like this:

 

(it's just an example, YMMV)

;disable all heaters
{% snippet 'disable_hotends' %}
{% snippet 'disable_bed' %}
;end retract
M302 S0
G90
G92 E11.0
G1 E0 F1500
M400
M302 S170
;reset settings
M501
;move to parking pos
T0
G0 X23 Y200 F10800
;G28 Z0
G0 Z200 F2000
; disable motors
M84
M117 

 

8 hours ago, georgp said:

And also the Fans on the sides seem not to work - just the main Fans is running when printing

 

I guess that's a different issue. You can test the fans in the "Advanced" menu.

Does it apply to both printheads?

 

 

[Anzen 0]

Sorry for the late response by modifying the gcode just by adding T1 works correctly

 

Edited February 17, 2020 by Anzen

[georgp 0]

18 hours ago, tinkergnome said:

 

In this case you can add these steps to the end-script in Cura or to the according gcode script in the printing host (if applicable).

My "print finished" script in Octoprint looks like this:

 

(it's just an example, YMMV)

;disable all heaters
{% snippet 'disable_hotends' %}
{% snippet 'disable_bed' %}
;end retract
M302 S0
G90
G92 E11.0
G1 E0 F1500
M400
M302 S170
;reset settings
M501
;move to parking pos
T0
G0 X23 Y200 F10800
;G28 Z0
G0 Z200 F2000
; disable motors
M84
M117 

 

 

I guess that's a different issue. You can test the fans in the "Advanced" menu.

Does it apply to both printheads?

 

 

Thanks!

I was using your end script and it is kinda doing what it should but it doesn't home the head and the building plate entirely so i still have to do that manually after a print. Is this also the case for you?

 

The fans seem to work now. 

 

I also have another issue:

I want to print with different nozzles (also a 1.5 mm nozzle) but i cannot find the nozzle diameter in cura anymore and also there are no settings for 1.5 mm nozzles. Any ideas how to use it?

 

And any advice if i want to print with 2 different nozzle sizes?

 

Thank you so much!

 

Cheers

Georg

[tinkergnome 927]

17 hours ago, georgp said:

doesn't home the head and the building plate entirely so i still have to do that manually after a print. Is this also the case for you?

 

Yes, that's intended (on my side) - it's the ymmv-part of the example 🙂

You can change the last few movements if you prefer the actual "homing".

Like so:

 

...

T0

G0 X23 Y200 F10800

G28 X0 Y0 ;home head

G0 Z200 F2000

G28 Z0 ;home buildplate
; disable motors

M84

...

 

17 hours ago, georgp said:

And any advice if i want to print with 2 different nozzle sizes?

 

I would choose the closest variant (a.k.a. nozzle size) per extruder and adjust the line width to the real size. Line width settings are the ones that count (make all of them visible first - there are quite a few).

 

 

[dfrez 21]

Just an update to my earlier post, I played around with the power budget settings and now I'm able to print with both nozzles running and bed at 100C. 😀

 

I originally had it at a much "safer" setting of 140/170/40/40. Changed it to 180/150/35/35, which I believe is the default and it seems to be working well so far. For what it's worth, the PN of my power brick has "GS" and not "GST" which @gr5 has stated is more prone to shutting down. 

 

Now I need to mess with the support material profile...

[Whom 7]

I thought I'd post another update as I've worked through a few issues specific to my use cases. 

 

I've been doing lots of ABS prints in a hot enclosure (70C+), and it seems like my magnets are getting weaker,  losing alignment or I don't know what. I was never able to reach the furthest corners without the head popping off but it got worse and worse. 

 

I modified the head and the coupling to include an additional 4 magnets and printed everything over 11 hours with a 0.25mm nozzle in ABS (fusion+ from Innofil/BASF, it's pretty good!).

 

I also beefed up the coupling to also act as a spacer for the head assembly. What I was finding was that the original design Z height of the coupling was dependant on the top height of the plastic part of the head. And this varied depending on how tight the screws were etc. My modification (which is pig ugly) is captured in the metal part of the head assembly and so is more accurately set over time.

 

It is rock solid now, I think my magnets were crappy but now I've got 7 of them I think there is a nice safety factor. 

 

Also just found a great trick using "terrain to STL" and switching the shell extruder to a different colour for contour lines. 

 

One quick question for tinkergnome, why is it that you've set the maximum temp adjust to be + or - 25 in the Mark2 firmware but not in your normal UM2 firmware? Thanks again for the epic work everyone, I could never go back to a single extruder now.  

[tinkergnome 927]

12 hours ago, Whom said:

One quick question for tinkergnome, why is it that you've set the maximum temp adjust to be + or - 25 in the Mark2 firmware but not in your normal UM2 firmware?

 

The switch to temperature offsets in the "tune" menu (instead of absolute values) was necessary because the gcode now contains a lot of temperature changes (for multi-extruder prints). I think there are four or five temperatures for each extruder in Cura.

Any absolute tuning value would be permanently overridden by the gcode and therefor pretty useless. The +/- 25C approach was more or less adopted from the brand new UM3 back then.

 

Just to be sure:

Do you miss the offsets in the old firmware or the absolute values for the Mark2?

 

 

BTW: Normal neodymium magnets are losing their magnetic effect irreversible above 80C.

But there are neodymium magnets with higher temperature grades available.

 

[Whom 7]

4 hours ago, tinkergnome said:

 

The switch to temperature offsets in the "tune" menu (instead of absolute values) was necessary because the gcode now contains a lot of temperature changes (for multi-extruder prints). I think there are four or five temperatures for each extruder in Cura.

Any absolute tuning value would be permanently overridden by the gcode and therefor pretty useless. The +/- 25C approach was more or less adopted from the brand new UM3 back then.

 

Just to be sure:

Do you miss the offsets in the old firmware or the absolute values for the Mark2?

 

 

BTW: Normal neodymium magnets are losing their magnetic effect irreversible above 80C.

But there are neodymium magnets with higher temperature grades available.

 

Ahh that makes sense, I really should have realised this. I miss the absolute value but only because as I switch back and forth between pla or abs if I forget to update the material settings in cura I can fix it when the print starts. But with the "temperature magic" I think you called it I understand why you switched to an offset. In a perfect world the offset limit could be more than 25 for the heated bed. Or I could just learn to check by slicing settings haha 

 

80! Of course, that would have done it then. I was assuming all could manage 100+ like an RC motor but I'm pretty sure I hit 80 at least once in the enclosure. The enclosure I build was too well insulated, I've ordered some fans and control boards to make it regulated. I'll go teach myself about magnets and order some more. 

 

Thank you! I hope nobody is offended by my ugly modifications haha 

[tinkergnome 927]

6 minutes ago, Whom said:

I'll go teach myself about magnets and order some more.

 

I think these explanations about the various grades are pretty comprehensive:

 

https://www.supermagnete.de/eng/faq/What-temperatures-can-magnets-withstand

 

https://www.supermagnete.de/eng/physical-magnet-data

 

 

11 minutes ago, Whom said:

I hope nobody is offended by my ugly modifications haha 

 

I guess the mechanism is a bit over-constrained now.... but if it works... who cares? 🙂

 

[Whom 7]

1 hour ago, tinkergnome said:

 

I think these explanations about the various grades are pretty comprehensive:

 

https://www.supermagnete.de/eng/faq/What-temperatures-can-magnets-withstand

 

https://www.supermagnete.de/eng/physical-magnet-data

 

 

 

I guess the mechanism is a bit over-constrained now.... but if it works... who cares? 🙂

 

Amazing, thank you. I've got some homework to do! I think I'm going to find some higher temp ones, perhaps a different shape and remodel the heads for my "heavy duty" needs. 

 

Yeah I was worried about it no longer being a 'tripod'. But since I stiffened up the coupler with side bars it's basically two flat planes and since I used the head to set the position of the coupler magnets there doesn't seem to be any misalignment gaps (yet). But I'll keep an eye on it. I aligned the slots with the center of rotation so it drops into place nicely. 

[georgp 0]

Hi there and thanks for your previous help. 

 

I Have a new Issue. 

I just wanted to print the entire print with heaed 2 because i do not always want to change nozzles but somehow it picks head 2 but then prints everything else with head 1 even if i select head 2 to print the entire object. 

 

Any idea?

 

Thanks!

Edited February 26, 2020 by georgp